WO2021036328A1 - 一种在sr网络中转发报文的方法、设备和系统 - Google Patents

一种在sr网络中转发报文的方法、设备和系统 Download PDF

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Publication number
WO2021036328A1
WO2021036328A1 PCT/CN2020/088788 CN2020088788W WO2021036328A1 WO 2021036328 A1 WO2021036328 A1 WO 2021036328A1 CN 2020088788 W CN2020088788 W CN 2020088788W WO 2021036328 A1 WO2021036328 A1 WO 2021036328A1
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Prior art keywords
identifier
identifiers
message
segment
network device
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PCT/CN2020/088788
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English (en)
French (fr)
Inventor
胡志波
李呈
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority claimed from CN201911317222.5A external-priority patent/CN112448888A/zh
Priority to JP2022513191A priority Critical patent/JP7403635B2/ja
Priority to EP20858296.5A priority patent/EP4009596B1/en
Priority to EP24209114.8A priority patent/EP4561013A3/en
Priority to MX2022002448A priority patent/MX2022002448A/es
Priority to KR1020227009215A priority patent/KR102777222B1/ko
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Priority to CA3177466A priority patent/CA3177466A1/en
Publication of WO2021036328A1 publication Critical patent/WO2021036328A1/zh
Priority to US17/681,137 priority patent/US12328260B2/en
Anticipated expiration legal-status Critical
Priority to US19/201,929 priority patent/US20250337686A1/en
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L49/00—Packet switching elements
    • H04L49/25—Routing or path finding in a switch fabric
    • H04L49/252—Store and forward routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/50—Routing or path finding of packets in data switching networks using label swapping, e.g. multi-protocol label switch [MPLS]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/34—Source routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/74—Address processing for routing
    • H04L45/741—Routing in networks with a plurality of addressing schemes, e.g. with both IPv4 and IPv6
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/74—Address processing for routing
    • H04L45/745—Address table lookup; Address filtering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/74—Address processing for routing
    • H04L45/745—Address table lookup; Address filtering
    • H04L45/748—Address table lookup; Address filtering using longest matching prefix
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L49/00—Packet switching elements
    • H04L49/30—Peripheral units, e.g. input or output ports
    • H04L49/3009—Header conversion, routing tables or routing tags
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/22—Parsing or analysis of headers

Definitions

  • This application relates to the field of communications, and in particular to a method, network equipment, and system for forwarding packets in a segment routing (SR) network.
  • SR segment routing
  • SR is a protocol designed based on the concept of source routing to forward data packets on the network. It supports the explicit designation of the data packet forwarding path at the source node.
  • IPv6 Internet Protocol Version 6
  • SRv6 segment routing SRv6
  • MPLS Multiple Protocol Label Switch
  • SRv6 extends the segment routing header (SRH) on the basis of IPv6.
  • the SRH includes a segment list (segment list), and the segment list includes a plurality of segment identifications (segment identification, SID) arranged in sequence, and each SID corresponds to a node or link in a packet forwarding path.
  • the SRH is encapsulated in a message, and the segment list is used to carry the forwarding and processing process of the message by the SR network.
  • each SID is a 128-bit (bit) IPv6 address. Since each SID occupies 128 bits in the message, each additional SID in the segment list will increase the length of the SRH by 128 bits, and correspondingly, the length of the message will also increase by 128 bits.
  • the increase of the packet length will cause a large amount of network resources, such as bandwidth, to be occupied during the forwarding process.
  • the message forwarding path includes 100 nodes
  • the SRH includes 100 SIDs
  • the segment list length is as high as 1600 bytes
  • the segment list length is too long, which reduces the efficiency of message transmission in the SR network.
  • the present application provides a method, device, and system for forwarding messages, which are used to solve the technical problem that the length of the segment list is too long and the message transmission efficiency in the SR network is reduced.
  • a method for forwarding messages includes: receiving a first message, the first message header of the first message includes a segment list for forwarding the first message, the segment list includes a plurality of identifiers arranged in sequence, so Each of the multiple identifiers corresponds to a network device or a link, and the segment list includes a first element with a length of 128 bits, and the first element includes adjacent ones of the multiple identifiers.
  • the first message includes a first pointer; the position of the first identifier in the first element is determined according to the value of the first pointer, and the first identifier is the at least two One of the identifiers; copy at least one identifier starting with the first identifier into the second header of the first message to generate a second message; send the second message .
  • the segment list may be the segment list in the SRH of the SRv6 message.
  • the 128-bit element in the segment list can store at least two identifiers corresponding to the network device, and each identifier does not need to occupy 128 bits, thereby reducing the length of the segment list, reducing the length of the message, and improving the message Transmission efficiency.
  • the number of identifiers stored in each 128-bit element can be adjusted according to the actual situation of the network. When a 128-bit element contains multiple identifiers, these identifiers can be understood as compressed segment identifiers (micro segment ID, USID). Through the first pointer included in the message header, the position of the compressed segment identifier inside the element can be obtained accurately and quickly.
  • the multiple identifiers are mapped to multiple segment identifiers one by one, and each segment identifier of the multiple segment identifiers corresponds to a network device or a link, and the multiple Each segment identifier in the segment identifier includes a first part and a second part, the first part of each segment identifier of the plurality of segment identifiers is the prefix part, and the prefix parts of the plurality of segment identifiers are the same, and Each identifier of the plurality of identifiers respectively includes the second part of the segment identifier to which each identifier is mapped.
  • the USID can be obtained by omitting part of the content in the SID. Since the BLOCK part of the SID of all network devices is the same in a domain, the USID can be obtained by omitting the BLOCK of the SID and put the USID in the segment list, thereby reducing the length of the segment list.
  • the second packet header includes a destination address (destiantion address, DA) field, and the destination address field includes a first part and a second part;
  • the first identifier is Copying the at least one initial identifier to the second message header of the first message includes: copying at least one identifier starting from the first identifier to the second part of the destination address field.
  • the first identifier is the identifier to be added to the DA field, which may also be referred to as the identifier to be added, and the first identifier may be USID.
  • the network device A pointer determines the first identifier among multiple identifiers, copies at least one identifier starting with the first identifier into the DA field, and the prefix part of the SID is also directly put into the DA field, so that the prefix part of the SID and At least one identifier starting from the first identifier is combined to guide message forwarding.
  • the lengths of the multiple identifiers are the same; the at least one identifier starting with the first identifier is copied to the second header of the first message Before the middle, the method further includes: determining the quantity of the at least one identifier according to the length of the plurality of identifiers and the length of the prefix part.
  • the DA field one part is occupied by the prefix part, and the other part is occupied by at least one USID copied to the DA field.
  • the network device can determine the number of at least one USID that can be copied to the DA field according to the length of the USID and the length of the prefix part.
  • the segment list does not include the prefix part.
  • the head node adds the SRH to the message, it also stores the currently pending USID and the BLOCK part corresponding to the USID in the DA field, where the USID adjacent to the BLOCK part in the DA field can be called the active USID. Therefore, for the active USID and other USIDs corresponding to the same prefix part as the active USID, the prefix part corresponding to these USIDs may no longer be stored in the segment list, but only the USIDs themselves. Thus, the length of the segment list is reduced.
  • the first message includes a destination address field, the destination address field includes a second identifier, and the second identifier is one of the multiple identifiers;
  • the method further includes: determining, according to the switching flag in the second identifier, that the segment list includes the second identifier and the second identifier.
  • the copying at least one identifier starting with the first identifier into the second header of the first message includes: adding the at least one identifier Is copied into the second message header to form a forwarding identifier stack, and the at least one identifier is of a different type from the second identifier.
  • the segment list can also include other types of identifiers, such as MPLS labels or Internet Protocol version 4 (Internet Protocol, IPv4) addresses.
  • the network device builds a forwarding label stack in the message header, and copies these other types of labels to the forwarding label stack. in. Therefore, the method can be compatible with more network scenarios, and the entire forwarding path can be programmed through the segment list to improve forwarding efficiency.
  • the first message includes a quantity flag; the at least one identifier starting with the first identifier is copied to the second message of the first message before the header, the method further includes: determining the quantity of the at least one identifier according to the value of the quantity flag.
  • at least one identifier is other types of identifiers, such as MPLS labels or IPv4 addresses. Before copying these other types of identifiers to the forwarding identifier stack, the network device can first determine the number of these other types of identifiers according to the quantity identifiers, thereby Copy the corresponding number of other types of identifiers to the forwarding identifier stack.
  • the determining the position of the first identifier in the first element according to the value of the first pointer includes: determining the number of redundant identifiers in the destination address field, so The type of the redundant identifier is different from the second identifier; the value of the first pointer is corrected according to the number of redundant identifiers; the value of the first pointer is determined to be in the first pointer according to the corrected value of the first pointer Position in an element.
  • the first identifier is the first identifier among at least one other type of identifier, and the redundant identifier is another type of identifier that has been added to the DA field.
  • the network device corrects the value of the first pointer according to the number of other types of identifiers that have been added to the DA field, and determines at least one identifier to be added to the DA field in the segment list according to the corrected value of the first pointer Starting position.
  • the copying at least one identifier starting with the first identifier to the forwarding identifier stack includes: using the last identifier of the at least one identifier as the last identifier. An identifier is added to the destination address field of the first message.
  • the network device also copies the compressed segment identifiers after other types of identifiers in the segment list into the DA field, so that after the forwarding identifier stack is popped out, it continues to forward packets according to the DA field.
  • the at least one identifier is an MPLS label or an IPv4 address.
  • the other type of identification may be an MPLS label or an IPv4 address.
  • the first pointer is included in the first packet header.
  • the first pointer can be in the specific field of the SRH or in the segment list.
  • the method further includes: The value of the first pointer is modified so that the modified value of the first pointer is used to indicate the position of the second identifier in the first element, and the second identifier does not belong to the at least one identifier.
  • the network device modifies the value of the first pointer so that the value of the first pointer always points to the identifier to be added, so that subsequent network devices on the forwarding path can continue to determine the identifier to be added according to the value of the first pointer.
  • the method further includes: Modify the value of the first pointer so that the modified value of the first pointer is used to indicate the position of the second identifier in the second element, and the second identifier does not belong to the at least one identifier, The second element is different from the first element.
  • the network device may point the first pointer to the identifier in the next element, for example, reset the value of the first pointer to 0, thereby pointing to the starting position of the next element.
  • a method for forwarding messages includes: receiving a first message; obtaining a segment list, the segment list corresponding to a forwarding path of the first message, the forwarding path includes a plurality of network devices, and the segment list includes a plurality of Each identifier of the plurality of identifiers respectively corresponds to a network device of the plurality of network devices or a link in the forwarding path, and the segment list includes the first segment list with a length of 128 bits.
  • the first element includes at least two adjacent identifiers among the plurality of identifiers; adding the segment list to the first message to generate a second message, the second message including A first pointer, the value of the first pointer is used to indicate the position of a first identifier in the first element, and the first identifier is one of the at least two identifiers; sending the second message .
  • the segment list may be the segment list in the SRH of the SRv6 message.
  • the 128-bit element in the segment list can store at least two identifiers corresponding to the network device, and each identifier does not need to occupy 128 bits, thereby reducing the length of the segment list, reducing the length of the message, and improving the message Transmission efficiency.
  • the number of identifiers stored in each 128-bit element can be adjusted according to the actual situation of the network.
  • the ingress node on the message forwarding path adds a first pointer to the message header, which is used to indicate the position of the different identifiers inside the element, so that the middle of the message forwarding path The node can accurately and quickly obtain the position of the mark inside the element.
  • each segment identifier of the plurality of segment identifiers includes a first part and a second part, the first part of each segment identifier is a prefix part, and the plurality of segment identifiers The prefix part is the same, and each of the plurality of identifiers respectively includes the second part of the segment identifier to which each identifier is mapped.
  • the USID can be obtained by omitting part of the content in the SID. Since the BLOCK part of the SID of all network devices in a domain is the same, the USID can be obtained by omitting the BLOCK part of the SID and put the USID in the segment list, thereby reducing the length of the segment list.
  • the message header of the first message includes a destination address field, and the destination address field includes a first part and a second part; and the adding the first message to the first message Segment list to generate the second message, including: adding the prefix part to the first part of the destination address field; adding one or one of the multiple identifiers to the second part of the destination address field Multiple logos. Since the prefix part of the SID is omitted from the USID in the segment list, the ingress node on the forwarding path directly adds the prefix part to the DA field, and also adds the first identifier in the segment list to the DA field, so that the SID The prefix part of and the first identifier are combined to guide message forwarding.
  • the segment list does not include the prefix part.
  • the prefix part of the SID is stored in the DA field, and only the USID is stored in the segment list, and the prefix part of the SID is no longer stored.
  • the length of the segment list is reduced.
  • At least one of the multiple identifiers is an MPLS label or an IPv4 address.
  • the second message includes a quantity flag, and the value of the quantity flag is used to indicate the quantity of the at least one identifier.
  • the segment list may also include other types of identifiers.
  • the ingress node of the forwarding path adds a quantity flag to the message to indicate the quantity of other types of identifiers.
  • the first pointer is located in a message header of the second message.
  • the first pointer can be in the specific field of the SRH or in the segment list.
  • the second message further includes a second pointer, and the value of the second pointer is used to indicate the position of the first element in the segment list.
  • the second pointer may be a segment left (SL) pointer.
  • the obtaining the segment list includes: receiving the segment list.
  • the segment list may be received by the ingress node of the forwarding path from the controller in the network.
  • the obtaining the segment list includes: determining the forwarding path of the first packet, and generating the segment list corresponding to the forwarding path.
  • the segment list may be generated by the entry node of the forwarding path.
  • a method for generating a segment list for forwarding a message includes: determining a forwarding path of the message, and the forwarding path includes a plurality of network devices;
  • the segment list corresponding to the forwarding path is generated, the segment list includes the plurality of identifiers arranged in sequence, and each identifier of the plurality of identifiers corresponds to a network of the plurality of network devices.
  • the segment list includes a first element with a length of 128 bits, and the first element includes at least two adjacent identifiers among the plurality of identifiers.
  • the method may be executed by a network device that generates a segment list, and the network device that generates the segment list may be a controller in the network, or an ingress node of a packet forwarding path in the network.
  • the segment list may be the segment list in the SRH of the SRv6 message.
  • the network device stores at least two identifiers corresponding to the network device in an element with a length of 128 bits in the segment list, instead of storing only one identifier per 128 bits, thereby reducing the length of the segment list, reducing the length of the message, and improving the message Transmission efficiency.
  • the number of identifiers stored in each 128-bit element can be adjusted according to the actual situation of the network. When a 128-bit element contains multiple identifiers, these identifiers can be understood as compressed segment identifiers (USID).
  • the multiple identifiers are mapped to multiple segment identifiers one by one, and each segment identifier in the multiple segment identifiers corresponds to a network device or one of the multiple network devices.
  • each of the plurality of segment identifiers includes a first part and a second part, the first part of each of the segment identifiers is a prefix part, and each of the plurality of identifiers Each identifier respectively includes the second part of the segment identifier to which each identifier is mapped.
  • the USID can be obtained by omitting part of the content in the SID. Since the BLOCK part of the SID of all network devices in a domain is the same, the USID can be obtained by omitting the BLOCK part of the SID and put the USID in the segment list, thereby reducing the length of the segment list.
  • the segment identifiers in the plurality of segment identifiers further include a third part, the third part is a filling part, the filling parts of the multiple segment identifiers are the same, and the multiple identifiers
  • the mark in does not include the filling part.
  • the function field in the USID may be a compressed function field, and the length of the compressed function field is less than the length of the uncompressed function field. Therefore, the length of the USID is less than the length of the SID, and the USID is put into the segment list, thereby reducing the length of the segment list.
  • the multiple segment identifiers include a first segment identifier, and the segment list does not include a prefix part of the first segment identifier.
  • the multiple segment identifiers include a first segment identifier, and the segment list does not include a prefix part of the first segment identifier. Only the USID is stored in the segment list, and the prefix part of the SID is no longer stored. Thus, the length of the segment list is reduced.
  • the multiple segment identifiers further include a second segment identifier
  • the prefix part of the first segment identifier is different from the prefix part of the second segment identifier
  • the segment list includes the The prefix part of the second paragraph identification.
  • At least one of the multiple identifiers is a segment identifier, an MPLS label, or an IPv4 address.
  • the segment list further includes a quantity flag, and the value of the quantity flag is used to indicate the quantity of the at least one other identifier.
  • the method further includes: sending the segment list to the ingress device of the forwarding path; or The segment list is encapsulated in a message, and the message is sent.
  • the network device that generates the segment list is the controller in the network
  • the controller generates the segment list and sends it to the ingress node of the forwarding path, so that the ingress node encapsulates the segment list into the message and instructs the message to be forwarded.
  • the network device that generates the segment list is the ingress node of the message forwarding path, the ingress node encapsulates the segment list into the message to guide the message forwarding.
  • a network device that executes the first aspect or any one of the possible implementations of the first aspect, or the fifteenth aspect or the method in any one of the fifteenth aspects.
  • the network device includes a unit for executing the method in the first aspect or any one of the possible implementation manners of the first aspect, or the fifteenth aspect or any one of the possible implementation manners of the fifteenth aspect.
  • a network device that executes the second aspect or any one of the possible implementation manners of the second aspect, or the sixteenth aspect or the method in any one of the sixteenth aspect.
  • the network device includes a unit configured to execute the second aspect or any one possible implementation manner of the second aspect, or the sixteenth aspect or any one possible implementation manner of the sixteenth aspect.
  • a network device that executes the third aspect or the method in any one of the possible implementation manners of the third aspect.
  • the network device includes a unit for executing the third aspect or the method in any one of the possible implementation manners of the third aspect.
  • a network device in a seventh aspect, includes a processor, a communication interface, and a memory.
  • the communication interface can be a transceiver.
  • the memory may be used to store program code, and the processor is used to call the program code in the memory to execute any one of the foregoing first aspect or any possible implementation of the first aspect, or any one of the fifteenth aspect or the fifteenth aspect. The implementation method of, will not be repeated here.
  • a network device in an eighth aspect, includes a processor, a communication interface, and a memory.
  • the communication interface can be a transceiver.
  • the memory may be used to store program code, and the processor is used to call the program code in the memory to execute any one of the foregoing second aspect or any possible implementation of the second aspect, or any one of the sixteenth aspect or the sixteenth aspect. The implementation method of, will not be repeated here.
  • a network device in a ninth aspect, includes a processor, a communication interface, and a memory.
  • the communication interface can be a transceiver.
  • the memory may be used to store program code, and the processor is used to call the program code in the memory to execute the foregoing third aspect or any one of the possible implementation manners of the third aspect, which will not be repeated here.
  • a network system in a tenth aspect, includes the network device provided by the foregoing fourth, fifth, or sixth aspect, or the network system includes the network device provided by the foregoing seventh, eighth, or ninth aspect.
  • a computer-readable storage medium stores instructions that, when run on a computer, cause the computer to execute the first, second, and third aspects described above.
  • the twelfth aspect provides a computer program product including computer program instructions.
  • the network device executes the first aspect, the second aspect, the third aspect, and the fifteenth aspect.
  • the sixteenth aspect, any possible implementation of the first aspect, any possible implementation of the second aspect, any possible implementation of the third aspect, any one of the fifteenth aspect One possible implementation manner or the method provided in any one of the possible implementation manners of the sixteenth aspect.
  • a chip including a memory and a processor, the memory is used to store a computer program, and the processor is used to call and run the computer program from the memory to execute the first aspect and any possible aspects of the first aspect.
  • the processor executes the method in the second aspect or any possible implementation of the second aspect, or the processor executes the third aspect or the method in any possible implementation of the third aspect, or The processor executes the fifteenth aspect or the method in any one possible implementation manner of the fifteenth aspect, or the processor executes the sixteenth aspect or the method in any one possible implementation manner of the sixteenth aspect.
  • the aforementioned chip only includes a processor, and the processor is used to read and execute a computer program stored in the memory.
  • the processor executes the first aspect or any possible implementation method of the first aspect.
  • the processor executes the method in the second aspect or any possible implementation manner of the second aspect, or the processor executes the method in the third aspect or any possible implementation manner of the third aspect, or the processor executes the fifteenth aspect Aspect or the method in any possible implementation manner of the fifteenth aspect, or the processor executes the method in the sixteenth aspect or any one of the possible implementation manners of the sixteenth aspect.
  • a method for forwarding messages includes: receiving a first message, the first message header of the first message includes a segment list for forwarding the first message, the segment list includes a plurality of identifiers arranged in sequence, so The identifier in the multiple identifiers corresponds to a network device or a link, the segment list includes a first element and a second element, and the length of the first element and the second element is 128 bits, and the first element and the second element are 128 bits in length.
  • An element includes at least two adjacent identifiers among the plurality of identifiers; the second header of the first message includes a destination address field, the destination address field includes the first identifier, and the first An identifier is one of the multiple identifiers; the second element is added to the destination address field according to the indication of the first identifier to generate a second message; and the second message is sent.
  • the segment list may be the segment list in the SRH of the SRv6 message.
  • the 128-bit element in the segment list can store at least two identifiers corresponding to the network device, and each identifier does not need to occupy 128 bits, thereby reducing the length of the segment list, reducing the length of the message, and improving the message Transmission efficiency.
  • these identifiers can be understood as compressed segment identifiers (USID).
  • USID compressed segment identifiers
  • the segment list can also store a segment identifier (SID) with a length of 128 bits, that is, the SID and the USID are stored in the segment list at the same time.
  • SID and USID correspond to different adding methods, so it is necessary to set a switching flag between USID and SID.
  • the network device can obtain the switching flag from the DA field and take corresponding actions according to the instructions of the switching flag. For example, when the SID is added to the DA field, the entire 128-bit element in the segment list is added to the DA field. Thus, the message forwarding is ensured.
  • a method for forwarding messages includes: receiving a first message, the first message header of the first message includes a segment list for forwarding the first message, the segment list includes a plurality of identifiers arranged in sequence, so Each of the multiple identifiers corresponds to a network device or a link, and the segment list includes a first element with a length of 128 bits, and the first element includes adjacent ones of the multiple identifiers.
  • the first message includes a first pointer; the position of the first identifier in the segment list is determined according to the value of the first pointer, and the first identifier is in the at least two identifiers Copying at least one identifier starting with the first identifier to the second header of the first message to generate a second message; sending the second message.
  • the segment list may be the segment list in the SRH of the SRv6 message.
  • the 128-bit element in the segment list can store at least two identifiers corresponding to the network device, and each identifier does not need to occupy 128 bits, thereby reducing the length of the segment list, reducing the length of the message, and improving the message Transmission efficiency.
  • the number of identifiers stored in each 128-bit element can be adjusted according to the actual situation of the network. When a 128-bit element contains multiple identifiers, these identifiers can be understood as compressed segment identifiers (micro segment ID, USID). Through the first pointer included in the message header, the position of the compressed segment identifier inside the element can be obtained accurately and quickly.
  • the multiple identifiers are mapped to multiple segment identifiers one by one, and each segment identifier of the multiple segment identifiers corresponds to a network device or a link, and the multiple Each segment identifier in the segment identifier includes a first part and a second part, the first part of each segment identifier of the plurality of segment identifiers is the prefix part, and the prefix parts of the plurality of segment identifiers are the same, and Each identifier of the plurality of identifiers respectively includes the second part of the segment identifier to which each identifier is mapped.
  • the USID can be obtained by omitting part of the content in the SID. Since the BLOCK part of the SID of all network devices is the same in a domain, the USID can be obtained by omitting the BLOCK of the SID and put the USID in the segment list, thereby reducing the length of the segment list.
  • the second packet header includes a destination address (destiantion address, DA) field, and the destination address field includes a first part and a second part;
  • the first identifier is Copying the at least one initial identifier to the second message header of the first message includes: copying at least one identifier starting from the first identifier to the second part of the destination address field.
  • the first identifier is the identifier to be added to the DA field, which may also be referred to as the identifier to be added, and the first identifier may be USID.
  • the network device A pointer determines the first identifier among multiple identifiers, copies at least one identifier starting with the first identifier into the DA field, and the prefix part of the SID is also directly put into the DA field, so that the prefix part of the SID and At least one identifier starting from the first identifier is combined to guide message forwarding.
  • the lengths of the multiple identifiers are the same; the at least one identifier starting with the first identifier is copied to the second header of the first message Before the middle, the method further includes: determining the quantity of the at least one identifier according to the length of the plurality of identifiers and the length of the prefix part.
  • the DA field one part is occupied by the prefix part, and the other part is occupied by at least one USID copied to the DA field.
  • the network device can determine the number of at least one USID that can be copied to the DA field according to the length of the USID and the length of the prefix part.
  • the segment list does not include the prefix part.
  • the head node adds the SRH to the message, it also stores the currently pending USID and the BLOCK part corresponding to the USID in the DA field, where the USID adjacent to the BLOCK part in the DA field can be called the active USID. Therefore, for the active USID and other USIDs corresponding to the same prefix part as the active USID, the prefix part corresponding to these USIDs may no longer be stored in the segment list, but only the USIDs themselves. Thus, the length of the segment list is reduced.
  • the first message includes a destination address field, the destination address field includes a second identifier, and the second identifier is one of the multiple identifiers;
  • the method further includes: determining, according to the switching flag in the second identifier, that the segment list includes the second identifier and the second identifier. Identifiers with different types of identifiers; the copying at least one identifier starting with the first identifier into the second header of the first message includes: copying the at least one identifier Into the second message header to form a forwarding identifier stack, and the at least one identifier is of a different type from the second identifier.
  • the segment list can also include other types of identifiers, such as MPLS labels or Internet Protocol version 4 (Internet Protocol, IPv4) addresses.
  • the network device builds a forwarding label stack in the message header, and copies these other types of labels to the forwarding label stack. in. Therefore, the method can be compatible with more network scenarios, and the entire forwarding path can be programmed through the segment list to improve forwarding efficiency.
  • the first message includes a quantity flag; the at least one identifier starting with the first identifier is copied to the second message of the first message before the header, the method further includes: determining the quantity of the at least one identifier according to the value of the quantity flag.
  • at least one identifier is other types of identifiers, such as MPLS labels or IPv4 addresses. Before copying these other types of identifiers to the forwarding identifier stack, the network device can first determine the number of these other types of identifiers according to the quantity identifiers, thereby Copy the corresponding number of other types of identifiers to the forwarding identifier stack.
  • the copying at least one identifier starting with the first identifier to the forwarding identifier stack includes: using the last identifier of the at least one identifier as the last identifier. An identifier is added to the destination address field of the first message.
  • the network device also copies the compressed segment identifiers after other types of identifiers in the segment list into the DA field, so that after the forwarding identifier stack is popped out, it continues to forward packets according to the DA field.
  • the at least one identifier is an MPLS label or an IPv4 address.
  • the other type of identification may be an MPLS label or an IPv4 address.
  • the first pointer is included in the first packet header.
  • the first pointer can be in the specific field of the SRH or in the segment list.
  • the method further includes: The value of the first pointer is modified so that the modified value of the first pointer is used to indicate the position of the second identifier in the segment list, and the second identifier does not belong to the at least one identifier.
  • the network device modifies the value of the first pointer so that the value of the first pointer always points to the identifier to be added, so that subsequent network devices on the forwarding path can continue to determine the identifier to be added according to the value of the first pointer.
  • a method for forwarding messages includes: receiving a first message; obtaining a segment list, the segment list corresponding to a forwarding path of the first message, the forwarding path includes a plurality of network devices, and the segment list includes a plurality of Each identifier of the plurality of identifiers respectively corresponds to a network device of the plurality of network devices or a link in the forwarding path, and the segment list includes the first segment list with a length of 128 bits.
  • the first element includes at least two adjacent identifiers among the plurality of identifiers; adding the segment list to the first message to generate a second message, the second message including The first pointer, the value of the first pointer is used to indicate the position of the first identifier in the segment list, and the first identifier is one of the at least two identifiers; and the second message is sent.
  • the segment list may be the segment list in the SRH of the SRv6 message.
  • the 128-bit element in the segment list can store at least two identifiers corresponding to the network device, and each identifier does not need to occupy 128 bits, thereby reducing the length of the segment list, reducing the length of the message, and improving the message Transmission efficiency.
  • the number of identifiers stored in each 128-bit element can be adjusted according to the actual situation of the network.
  • the ingress node on the message forwarding path adds a first pointer to the message header, which is used to indicate the position of the different identifiers in the segment list, so that the message forwarding path is The intermediate node can accurately and quickly obtain the position of the identifier in the segment list.
  • each segment identifier of the plurality of segment identifiers includes a first part and a second part, the first part of each segment identifier is a prefix part, and the plurality of segment identifiers The prefix part is the same, and each of the plurality of identifiers respectively includes the second part of the segment identifier to which each identifier is mapped.
  • the USID can be obtained by omitting part of the content in the SID. Since the BLOCK part of the SID of all network devices in a domain is the same, the USID can be obtained by omitting the BLOCK part of the SID and put the USID in the segment list, thereby reducing the length of the segment list.
  • the message header of the first message includes a destination address field, and the destination address field includes a first part and a second part; and the adding the first message to the first message Segment list to generate the second message, including: adding the prefix part to the first part of the destination address field; adding one or one of the multiple identifiers to the second part of the destination address field Multiple logos. Since the prefix part of the SID is omitted from the USID in the segment list, the ingress node on the forwarding path directly adds the prefix part to the DA field, and also adds the first identifier in the segment list to the DA field, so that the SID The prefix part of and the first identifier are combined to guide message forwarding.
  • the segment list does not include the prefix part.
  • the prefix part of the SID is stored in the DA field, and only the USID is stored in the segment list, and the prefix part of the SID is no longer stored.
  • the length of the segment list is reduced.
  • At least one of the multiple identifiers is an MPLS label or an IPv4 address.
  • the second message includes a quantity flag, and the value of the quantity flag is used to indicate the quantity of the at least one identifier.
  • the segment list may also include other types of identifiers.
  • the ingress node of the forwarding path adds a quantity flag to the message to indicate the quantity of other types of identifiers.
  • the first pointer is located in a message header of the second message.
  • the first pointer can be in the specific field of the SRH or in the segment list.
  • the obtaining the segment list includes: receiving the segment list.
  • the segment list may be received by the ingress node of the forwarding path from the controller in the network.
  • the obtaining the segment list includes: determining the forwarding path of the first packet, and generating the segment list corresponding to the forwarding path.
  • the segment list may be generated by the entry node of the forwarding path.
  • FIG. 1 is a schematic diagram of an application scenario provided by an embodiment of the application
  • FIG. 2 is a schematic diagram of a format of an SID provided by an embodiment of the application.
  • FIG. 3 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 4 is a schematic structural diagram of a segment list provided by an embodiment of this application.
  • FIG. 5 is a schematic structural diagram of a SID provided by an embodiment of this application.
  • FIG. 6 is a schematic structural diagram of a segment list provided by an embodiment of this application.
  • FIG. 7 is a schematic structural diagram of a segment list provided by an embodiment of this application.
  • FIG. 8 is a schematic structural diagram of a segment list provided by an embodiment of this application.
  • FIG. 9 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 10 is a schematic diagram of the structure of a message provided by an embodiment of this application.
  • FIG. 11 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 12 is a schematic diagram of the structure of a message provided by an embodiment of this application.
  • FIG. 13 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 14 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 15 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 16 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 17 is a schematic diagram of the structure of a message provided by an embodiment of the application.
  • FIG. 18 is a flowchart of a method for processing a message according to an embodiment of the application.
  • FIG. 19 is a flowchart of a method for processing a message according to an embodiment of the application.
  • FIG. 20 is a schematic structural diagram of a network device provided by an embodiment of this application.
  • FIG. 21 is a schematic structural diagram of a network device provided by an embodiment of this application.
  • FIG. 22 is a schematic structural diagram of a network device provided by an embodiment of this application.
  • FIG. 23 is a schematic structural diagram of a network device provided by an embodiment of this application.
  • FIG. 24 is a schematic structural diagram of a network device provided by an embodiment of this application.
  • FIG. 25 is a schematic structural diagram of a network system provided by an embodiment of this application.
  • FIG. 1 shows a possible application scenario of an embodiment of the present application.
  • the network of this application scenario includes network equipment, specifically: network equipment S, network equipment 1, network equipment 2, network equipment 3, network equipment 4, network equipment 5, network equipment 6, network equipment 7, network equipment 8, network Device 9, network device 10, network device 11, and network device 12.
  • These network devices can be switches, routers or repeaters.
  • the network device S may be an entrance device of the network.
  • the network device may also include a controller, which is not shown in FIG. 1.
  • the controller can be connected to network devices 1 to 10.
  • the controller may generate a segment list corresponding to the forwarding path of the message, and send the segment list to the network entry device.
  • the controller may send control messages containing network configuration information to the network devices 1-12.
  • the network devices in the embodiments of the present application may also be referred to as network nodes or nodes.
  • the network device S is a network device that supports SR.
  • the network devices 1 to 12 may be network devices that support SR.
  • the network devices may be network devices that support SRv6, or the network devices may also be network devices that support MPLS.
  • the network device 1 to the network device 12 may also be network devices that support IPv4 but do not support SR.
  • each segment In the SR network, the message processing process is composed of multiple segments, and each segment is an instruction or a set of instructions for processing the message.
  • each segment has a corresponding segment identifier, that is, SID.
  • the segment identifier includes two types: node segment identifier (node SID) and adjacent segment identifier (adjacent SID).
  • Figure 2 shows the format of the SID in the SRv6 network. As shown in Figure 2, each SID may include a location (Locator) field and a function (Function) field.
  • the location field in the SID is used to locate the specific network device that executes the instruction or instruction set included in the segment.
  • the location field includes a prefix (BLOCK) part and a sequence number (Node ID) part.
  • BLOCK prefix part of the SID of the network device
  • Node ID sequence number
  • the prefix part of the SID of the network device may be the same.
  • the sequence number part of the SID of each network device is different, and each sequence number part is used to uniquely identify a network device in the domain.
  • the network device that is uniquely determined by the sequence number part of the SID is the network device that executes the segment identified by the SID.
  • the function field in the SID is used to indicate the specific content of the instruction or instruction set included in the segment, that is, the function in the SRv6 network.
  • the functions in the SRv6 network may also involve parameters, which are represented by the Argument field in the SID (not shown in Figure 2). When the function does not involve parameters, the parameter field may not be included in the SID.
  • the total length of the SID in the SRv6 network is 128 bits.
  • the location field and the function field are respectively specific lengths, and these specific lengths can be changed through network settings.
  • the position field is 48 bits and the function field is 80 bits, or the position field is 64 bits and the function field is 64 bits, or the position field is 48 bits, the function field is 64 bits, and the parameter field is 16 bits.
  • FIG. 3 shows the message format in the SRv6 network.
  • the header of the message includes an IPv6 header and an SRH.
  • the IPv6 header includes a destination address (DA) field.
  • the SRH includes a segment list, and the segment list includes multiple SIDs arranged in sequence. . These SIDs can be node segment identifiers, adjacent segment identifiers, or a combination of node segment identifiers and adjacent segment identifiers.
  • the segment list can be encapsulated in the message by the ingress node on the message forwarding path, and subsequent network devices on the message forwarding path can process the message according to the segment list in the message.
  • the message is sent by an ingress node on the forwarding path, and a specific network device on the forwarding path receives the message.
  • the network device determines that the DA field of the IPv6 header of the message includes the SID of the network device, and then processes the message according to the instruction set corresponding to the segment identified by the SID.
  • the specific manner of processing the message may be, for example, forwarding the message.
  • the network device also needs to update the DA field.
  • the segment list includes multiple SIDs arranged in sequence, namely Segment List[0] to Segment List[n].
  • the multiple SIDs respectively correspond to multiple network devices on the packet forwarding path, and the multiple network devices respectively execute instruction sets corresponding to multiple segments.
  • the SL pointer can point to multiple SIDs in the segment list in turn.
  • the value of the SL pointer is updated every time a segment is executed. After each update, the position of the SL pointer in the segment list is offset by the length of an SID, that is, 128 bits.
  • the multiple segments represented by multiple SIDs in the segment list are executed sequentially, and the value of the SL pointer is constantly updated. Therefore, the SL pointer is used to indicate the number of remaining segments in the segment list to be processed. In other words, each value of the SL pointer corresponds to a specific number of remaining segments to be processed in the segment list, and the SL pointer always points to the currently pending SID.
  • the multiple SIDs are arranged in the reverse order in the segment list, that is, the SID of the first executed segment is arranged at the end of the segment list.
  • the SIDs of the subsequently executed sections are arranged upwards, and the SID of the last executed section is arranged at the top of the section list.
  • Segment List[n] represents the first executed segment
  • Segment List[0] represents the last executed segment.
  • the value of the SL pointer is 3, which means that the number of remaining segments to be processed in the segment list is 4. It can also be understood that the SL pointer points to the current SID to be processed, that is, the fourth SID counted from bottom to top; SL The value of the pointer is 0, which means that the number of remaining segments to be processed is 1.
  • the SL pointer points to the current SID to be processed, that is, the last SID counted from bottom to top, that is, the Segment List[ in Figure 3 0].
  • the SID is copied to the DA field in the IPv6 packet header for subsequent processing of the packet according to the content in the DA field.
  • the specific manner of processing the message may be, for example, forwarding the message.
  • the processing method may be forwarding, that is, the message is forwarded through the network shown in FIG. 1.
  • network device S sends a message to network device 10, and the forwarding path of the message sequentially passes through network device 1, network device 2, network device 3, network device 4, network device 5, network device 6, network device 7, and network device.
  • the forwarding path also includes network device 1 to network device 10, a total of 10 network devices.
  • the segment list of the entire message forwarding process includes 10 SIDs.
  • the length of each SID is 128 bits, and the length of the segment list is 160 bytes.
  • the embodiment of the present application provides a method for forwarding a message, and a device and system based on the method. These methods, equipment and systems are based on the same inventive concept.
  • a compressed segment identifier with a smaller length can be used instead of a 128-bit SID, thereby reducing the length of the segment list, thereby reducing the length of the message, and improving the transmission efficiency and processing efficiency of the network.
  • the embodiment of the present invention provides a method for forwarding a message.
  • the method involves each node on the forwarding path of the message.
  • the network device S sends a message to the network device 10, and the forwarding path of the message sequentially passes through the network device 1, the network device 2, the network device 3, the network device 4, the network device 5, and the network device 6. , Network equipment 7, network equipment 8, network equipment 9.
  • the steps of the method include:
  • the network device S receives the message.
  • the network device S is a network entry device in the network, and is an entry node of the forwarding path of the message.
  • the network device S receives a message, and the message may be a message generated by a host (not shown in FIG. 1), and the host may be a terminal device such as a personal computer, a mobile phone, or a tablet computer.
  • the network device S needs to determine the forwarding path of the received message.
  • the network device S may find a forwarding path for forwarding the message from a plurality of stored forwarding paths according to the characteristics of the message, so as to determine the forwarding path of the message.
  • the stored multiple forwarding paths may be received by the network device S from the controller in the network.
  • the feature of the message may be any one element or a combination of multiple elements in the quintuple of the message.
  • the quintuple includes elements: the source IP address, source port, destination IP address, and destination of the message. Port and protocol number.
  • the network device S may also calculate a forwarding path for forwarding the message according to the information carried in the message and the network topology information.
  • the forwarding path includes multiple network devices.
  • the network device S sends a message to the network device 10, and the forwarding path of the message sequentially passes through the network device 1, the network device 2, the network device 3, the network device 4, the network device 5, and the network device 6. , Network equipment 7, network equipment 8, network equipment 9.
  • the network device S obtains the segment list.
  • the segment list may be the segment list in the SRH of the SRv6 message. As shown in FIG. 4, the segment list at this time corresponds to the forwarding path of the message, the forwarding path includes network device 1 to network device 10, and the segment list includes a plurality of SIDs arranged in sequence. Among the multiple SIDs Each SID of corresponds to one of the multiple network devices or a link in the forwarding path, and the length of each SID is 128 bits.
  • the segment list may be received by the network device S from the controller and stored in the device. Specifically, the network device S finds the forwarding path for forwarding the message from the stored multiple forwarding paths, and finds the corresponding List of segments in the forwarding path.
  • the segment list may also be generated by the network device S. Specifically, the network device S calculates a forwarding path for forwarding the message according to the information carried in the message, and generates a segment list corresponding to the forwarding path.
  • the forwarding path of a message can also be represented by multiple segments.
  • Each segment is executed by a specific network device, and each segment has a corresponding SID. Therefore, for a segment, there is a correspondence between the SID of this segment and the network device that executes the segment, that is, the SID corresponds to a network device, or it can be said that the SID is the SID of a network device.
  • the segment identifier of the network device 1 may be A:1:01:11::, the length of the segment identifier is 128 bits, and "::" represents all 0 bytes.
  • A:1:01 is the position field
  • the length is 48 bits
  • A:1/48 is the BLOCK part
  • the length is 32 bits
  • "/48” means the 48-bit mask
  • 01 is the serial number part
  • the length is 16 bits
  • 11:: is the function field
  • the length is 80 bits.
  • network equipment 2, network equipment 3, network equipment 4, network equipment 5, network equipment 6, network equipment 7, network equipment 8, network equipment 9, or network equipment 10 can also be network equipment in the same domain.
  • the segment identifiers of these network devices can be A:1:02:22::,A:1:03:33::,A:1:04:44::,A:1:05:55::, A:1:06:66::,A:1:07:77::,A:1:08:88::,A:1:09:99::,A:1:0a:aa::.
  • each SID In order to reduce the length of each SID, a certain part or parts of the SID can be omitted to form a compressed segment ID (microsegment ID, USID). These USIDs can be placed in the segment list instead of the SID to reduce the length of the segment list. .
  • the BLOCK part of the SID of all network devices can be the same, in order to reduce the length of each SID in the segment list, the BLOCK part of the SID can be omitted to form a USID. That is to say, the SID of the network device is divided into two parts, the first part is the BLOCK part, and the second part is the rest of the SID except the BLOCK part. When putting in the segment list, the same BLOCK part is omitted.
  • the SID of the network device 1 in Figure 1 is A:1:01:11::, where A:1/48 is the BLOCK part, 01 is the serial number part, and the length is 16 bits.
  • the remaining part is 01:11::, and the length is 96 bits.
  • network device 2, network device 3, network device 4, network device 5, network device 6, network device 7, network device 8, network device 9, or network device 10 can omit the BLOCK part of the location field of the SID.
  • the remaining parts are 02:22::,03:33::,04:44::,05:55::,06:66::,07:77::,08:88::,09:99 ::,0a:aa::.
  • the length of these remaining parts is less than the length of the SID.
  • the function field of the SID may also be set to a compressed format, and the function field of the compressed format is smaller than the function field of the uncompressed format.
  • all functional fields are divided into two parts: compressed functional fields and non-compressed functional fields.
  • FIG. 5 shows the SID including the compressed function field, and the SID including the non-compressed function field.
  • the compressed function field is used to indicate frequently used functions
  • the non-compressed function field is used to indicate uncommon functions.
  • the length of the compressed functional field is less than the length of the non-compressed functional field. For example, the length of the compressed functional field is 16 bits, and the length of the non-compressed functional field is 80 bits.
  • the compressed function field is followed by a padding part, and the padding part is the same specific content, so that the length of the entire SID is still 128 bits.
  • the filling part may be all zeros. Therefore, in order to reduce the length of the SID, when the function field in the SID is a compressed function field, the padding part after the compressed function field can be omitted to form a USID.
  • the SID of the network device 1 in FIG. 1 may be A:1:01:11::, where 11 is a function field, and is a compressed function field, the length is 16 bits, that is, the length of the padding part is 64 bits.
  • the padding part after the compressed function field of the SID is omitted, and the remaining part is A:1:01:11, and the length is 64 bits.
  • the remaining parts are A:1:02:22, A:1:03:33, A:1:04:44, A:1:05:55, A:1:06:66, A: 1:07:77, A:1:08:88, A:1:09:99, A:1:0a:aa.
  • the length of these remaining parts is less than the length of the SID.
  • the first bit of the compressed function field and the first bit of the uncompressed function field may be set to different values. Therefore, for the obtained SID, the network device can determine whether the function field of the SID is a compressed function field or an uncompressed function field through the first bit of the function field. For example, the first bit of a compressed functional field is 0, and the first bit of a non-compressed functional field is 1, or the first bit of a compressed functional field is 1, and the first bit of a non-compressed functional field is 1. The bit is 0.
  • the length of the remaining part can be further reduced.
  • the USID includes the sequence number part of the location field of the SID and the compressed function field.
  • the BLOCK part of the SID of the network device 1 in FIG. 1 and the padding part after the compressed function field can be omitted at the same time, and the remaining part is 01:11 and the length is 32 bits.
  • network equipment 2 network equipment 3, network equipment 4, network equipment 5, network equipment 6, network equipment 7, network equipment 8, network equipment 9, or network equipment 10 SID location field BLOCK part and compression function
  • the padding part after the field can be omitted, and the remaining parts are 02:22,03:33,04:44,05:55,06:66,07:77,08:88,09:99,0a:aa.
  • the length of these remaining parts is less than the length of the SID.
  • the length of the USID is less than 128 bits.
  • the length of the USID is variable.
  • the length of the USID is determined by the sum of the length of the sequence number part of the location field of the SID and the length of the compressed function field.
  • the length of the USID can be 16 bits, 32 bits, or 64 bits, and so on.
  • the compressed function fields of all SIDs have the same length, and all USIDs have the same length.
  • SIDs are arranged in sequence according to the order of the corresponding network equipment on the forwarding path, forming a segment list. Replacing the SID in the segment list with the corresponding USID can reduce the length of the segment list, thereby reducing the length of the message and improving network efficiency.
  • the space in the segment list is divided into multiple elements, and the SL pointer points to different elements after each update.
  • the space occupied by each SID can be divided into one element, that is, the length of each element is 128 bits, and the position pointed to by the SL pointer in the segment list is still offset by 128 bits after each update.
  • multiple elements in the segment list can be sorted.
  • the element initially pointed to by the SL pointer can be called the first element, and other elements can be deduced by analogy. Since the length of the USID is less than 128 bits, for example, the length of the USID can be 32 bits.
  • the network device S stores multiple USIDs, for example, at least two USIDs, in the 128-bit element of the segment list, thereby reducing the segment list
  • the BLOCK part of the location field of the SID may be included in the segment list, and the BLOCK part may be included in the first element in the segment list.
  • the BLOCK part of the location field of the SID may not be included in the segment list.
  • Figure 6 shows the structure of the segment list. For example, when the length of the USID is 32 bits, each element in the segment list stores 4 USIDs. For example, the first element stores USID1, USID2, USID3, and USID4, and the second element stores USID5, USID6, USID7, and USID8.
  • the network device S obtains the segment list.
  • the segment list corresponds to the forwarding path of the first packet, the forwarding path includes a plurality of network devices, the segment list includes a plurality of identifiers arranged in sequence, and the identifiers in the plurality of identifiers correspond to the plurality of network devices.
  • the segment list includes an element with a length of 128 bits, and the element includes at least two adjacent identifiers among the plurality of identifiers.
  • the multiple USIDs in the segment list are arranged in sequence according to the order of the corresponding network device on the forwarding path.
  • the arrangement of multiple USIDs within the element is not limited. Multiple USIDs can be arranged in order or in reverse order within the element.
  • the order of the 4 USIDs stored in the first element can be USID1, USID2, USID3 and USID4 from top to bottom.
  • the order of the 4 USIDs can also be USID4, USID3 from top to bottom. , USID2 and USID1.
  • the network device that generates the segment list can choose whether to generate the segment list including the USID.
  • the network device can publish masks of different lengths, corresponding to compressed function fields and non-compressed function fields, respectively.
  • the length of the mask identified by the compressed segment is the sum of the length of the position field in the SID and the length of the compressed function field
  • the length of the mask identified by the uncompressed segment is the length of the position field in the SID and the length of the uncompressed function field.
  • the length of the mask identified by the compressed segment is less than the length of the mask identified by the uncompressed segment.
  • the compressed mask length corresponding to the network device 1 is 64 bits
  • the uncompressed mask length corresponding to the network device 1 is 128 bits.
  • the network device that generates the segment list obtains the above-mentioned masks of different lengths issued by other network devices.
  • the segment list including the USID is bound to the mask of the compressed segment identifier.
  • the network device that generates the segment list generates the segment list including the SID, it binds the segment list including the SID with the uncompressed mask. Therefore, after the segment list is encapsulated in the message, the network device that forwards the message can obtain the SID or USID from the segment list by using masks of different lengths.
  • the segment list can include USID and other types of identifiers at the same time.
  • the other types of identifiers may be SIDs, that is to say, SIDs may still be mixed in the segment list adopting USID.
  • SIDs may still be mixed in the segment list adopting USID.
  • some network devices may not have the ability to process USIDs.
  • the segment list can still store 128-bit SIDs corresponding to these network devices.
  • network compatibility is improved.
  • the segment list stores the SID9 corresponding to the network device 9, that is, A:1:09:99:: with a length of 128 bits.
  • the network device that generates the segment list may decide to put the USID or SID of these network devices in the segment list according to whether other network devices have the ability to process USIDs.
  • the network device that generates the segment list may be a controller in the network, or an ingress node of a packet forwarding path, for example, the network device S shown in FIG. 1.
  • the network device S obtains a compression capability flag corresponding to the network device 9, and the compression capability flag is used to indicate whether the network device 9 has the ability to process the USID.
  • the network device S stores the USID corresponding to the network device 9 in the generated segment list.
  • the network device S stores the SID corresponding to the network device 9 in the generated segment list.
  • a prompt flag is included in the previous USID identified by the segment in the segment list, and the prompt flag is used to indicate the current USID
  • the latter identifier is an SID with a length of 128 bits.
  • the prompt flag may be included in the compressed function field part of the USID.
  • two associated compressed function fields can be set for each USID. When the reminder flag is included in the USID, one of the compressed function fields is used, and when the reminder flag is not included in the USID, the other compressed function field is used. Field. As shown in Fig. 6, two associated compressed function fields can be set for USID8, 87 and 88 respectively.
  • the reminder flag may be included in the USIDs other than the last USID among the consecutive multiple USIDs, that is, the reminder flag
  • the prompt flag may be included in the compressed function field part of the USID.
  • two associated compressed function fields can be set for each USID. When the reminder flag is included in the USID, one of the compressed function fields is used, and when the reminder flag is not included in the USID, the other compressed function field is used. Field. As shown in Fig. 6, two associated compressed function fields can be set for USID7, 77 and 78 respectively.
  • a reminder flag can be set at a fixed length every interval.
  • the reminder flag is used to indicate the type of the identifier in the next fixed length, that is, to indicate the next fixed length.
  • the fixed length may be 128 bits.
  • the prompt mark may be located in the last mark in the fixed length, and the prompt mark may also be an independent mark, which is not included in any mark corresponding to the network device.
  • the different values of the prompt flag correspond to different types of identifications.
  • a reminder flag can be set every 128 bits. The reminder flag is located in the last identifier of the 128 bits.
  • the reminder flag in USID8 When the value of the reminder flag in USID8 is 0, it means that the type of the identifier in the next 128 bits is SID, specifically, the next 128 bits are identified as SID9, and when the value of the prompt flag in USID4 is 1, it means that the type identified in the next 128 bits is USID, specifically, the next 128 bits are identified as USID5 , USID6, USID7 and USID8.
  • a reminder flag may also be set at a fixed length every interval, and the reminder flag is used to indicate whether the next fixed length still belongs to the current identifier. Therefore, the boundary of the current identification can be determined according to the prompt flag, and then the current identification is determined as an SID with a length of 128 bits or a USID with a length of less than 128 bits.
  • the fixed length may be 32 bits.
  • the fixed length can also be 8 bits, 16 bits, and so on.
  • the reminder flag may be located in one bit position.
  • the prompt flag may be located in the first bit or the last bit in the fixed length. As shown in Figure 6, a reminder flag can be set every 32 bits.
  • the reminder flag is located in the last bit of the 32 bits.
  • the value of this bit is 1, it means that the next fixed length still belongs to the current flag, and When the value of this bit is 0, it means that the next fixed length no longer belongs to the current identifier.
  • the value of the last bit is 0, which means that the following 32 bits no longer belong to the current identity, that is, the following 32 bits are USID8.
  • the value of the last bit is 0, which means that the following 32 bits no longer belong to the current identity, that is, the following 32 bits are the first 32 bits of SID9.
  • the value of the last bit is 1, indicating that the subsequent 32 bits still belong to the current identity, that is, the subsequent 32 bits are the second 32 bits of SID9.
  • the BLOCK part of the SID needs to be placed in the starting position of the next element of the SID in the segment list.
  • the segment list stores a 128-bit SID9 corresponding to the network device 9, and the next element in the segment list stores a BLOCK at the start position.
  • the BLOCK can be A:1 and the length is 32 bits.
  • multiple USIDs are stored in sequence, and after multiple USIDs are stored, if there are still extra bits at the end of the element, these extra bits can be filled. For example, fill these extra bits with all zeros.
  • the BLOCK part of the SID of all network devices is the same, but between different domains, the BLOCK part of the SID of the network device is different.
  • the BLOCK part of the SID of the network device is different.
  • the BLOCK part needs to be placed at the beginning of an element, that is, the BLOCK part is placed at the beginning of the next element of the USID of the previous hop network device, and then after the BLOCK part, put the The USID of the network device.
  • Fig. 7 shows a structure of a segment list.
  • the network device 9 and the network device 8 belong to different domains, and the SID of the network device 8 is A:1:8:88::,
  • the SID of network device 9 is A2:9:99::, that is, the BLOCK part of the SID of network device 8 is A:1, the BLOCK part of the SID of network device 9 is A2, and the USID8 of network device 8 is 8:88.
  • the USID9 of device 9 is 9:99.
  • the USID9 corresponding to the network device is stored in the next element of USID8, and the BLOCK is stored before USID9.
  • the BLOCK is A2 and the length is 32 bits.
  • the network device S adds a segment list to the message. Specifically, the network device S adds a segment list to the SRH of the message.
  • the message further includes an SL pointer.
  • the SRH includes an SL pointer, and the SL pointer points to a certain element in the segment list.
  • the intermediate node on the forwarding path adds the SID stored in the element pointed to by the SL pointer to the destination address (DA) field in the IPv6 header of the outer layer of the SRH.
  • the SL pointer is used to indicate the element currently to be processed in the segment list.
  • the message includes a first pointer, the value of the first pointer is used to indicate the position in the element of the first identifier that needs to be copied into the message header, and the new pointer may be referred to as a PI pointer.
  • the SL in the message can become the second pointer.
  • the value of the SL pointer is used to indicate the positions of different elements in the segment list, and the value of the PI pointer is used to indicate the positions of different USIDs in the element.
  • the intermediate node on the forwarding path can determine the identifier currently to be added in the element of the segment list according to the value of the PI pointer, for example, the USID currently to be added.
  • the location of the PI pointer may be in the message header, and the message header may be an SRH or IPv6 message header.
  • the PI pointer may be located in the PI field of the SRH, or the PI pointer may be located in the DA field of the IPv6 packet header.
  • the PI pointer can also be located in the segment list.
  • the PI pointer can be located in the first USID in each element in the segment list.
  • the PI pointer may be adjacent to the SL pointer.
  • Two adjacent pointers may be located in a specific field of the SRH, such as but not limited to the SL field.
  • the PI pointer is part of the SL field in SRH.
  • the last few bits in the SL field can be divided into PI pointers, and the other parts in the SL field can be used as SL pointers.
  • the last two bits in the SL field can be divided into PI pointers, and the other parts in the SL field can be used as SL pointers. That is, the PI pointer may be the last two bits in the SL field, that is, the least significant bit and the second least significant bit.
  • the SL pointer is used to indicate the element currently to be processed in the segment list
  • the PI pointer is used to indicate the position of the first identifier that needs to be copied into the message header in the current element to be processed.
  • the whole composed of the SL pointer and the PI pointer can also be regarded as a new pointer, and the SL pointer and the PI pointer are respectively part of the new pointer.
  • the message may only include a first pointer, and the value of the first pointer is used to indicate the position in the segment list of the first identifier that needs to be copied into the message header.
  • the new first pointer may be called For the XL pointer.
  • the XL pointer is a one-dimensional pointer.
  • the XL pointer may be located in a specific field in the SRH, such as the SL field, that is, the entire SL field may be used as the XL pointer.
  • the XL pointer may sequentially point to multiple identifiers in the segment list, and the multiple identifiers may be multiple types of identifiers, such as SID or USID.
  • the position pointed to by the XL pointer in the segment list is offset by the length of the identifier corresponding to the segment. For example, when the identifier of the offset is SID, the length is 128 bits, and when the identifier of the offset is USID, the length is less than 128 bits.
  • the XL pointer is used to indicate the position of the currently to-be-processed identifier in the segment list.
  • the network device S also adds the BLOCK part of the SID to the DA field of the IPv6 header in the message.
  • the network device S also adds at least one identifier to the DA field.
  • the at least one identification may be multiple identifications.
  • the multiple identities can be multiple USIDs, or a combination of USIDs and other types of identities.
  • the DA field of the IPv6 header in the message can also be divided into two parts.
  • the BLOCK part omitted from the segment list is placed in the first part of the DA field, and at least one identifier is placed in the second part of the DA field.
  • the number of at least one identifier added by the network device S in the DA field is determined by the length of the BLOCK and the length of the identifier.
  • the network device S adds as many identifiers as possible to the part other than the BLOCK in the DA field.
  • the number of multiple USIDs may be the integer part of (128-L BLOCK )/L USID , where L BLOCK is the length of BLOCK and L USID is the length of USID.
  • L BLOCK is the length of BLOCK
  • L USID is the length of USID.
  • 3 USIDs are added to the DA field.
  • the number of multiple identifiers including a combination of the USID and other types of identifiers may also be the integer part of (128-L BLOCK )/L USID.
  • the length of BLOCK is 32 bits
  • the length of USID is 32 bits
  • the length of MPLS label is 32 bits
  • a combination of 2 USIDs and 1 MPLS label is added to the DA field.
  • Figure 9 shows the structure of a message with a segment list and a PI pointer added.
  • the PI pointer is located in the PI field of the SRH.
  • the network device S adds the BLOCK part of the SID to the DA field.
  • 3 USIDs are added.
  • the three USIDs are USID1, USID2, and USID3.
  • the value of the PI pointer is 3, which means that the first 3 USIDs in this element of the segment list have been added to the DA field.
  • the identifier to be added in the element can be determined, that is, the fourth USID, USID4.
  • the network device S sends the message.
  • the network device S When the network device S sends the message, it will determine the next hop network device of the message according to the content of the DA field and the longest matching rule.
  • the DA field includes BLOCK and multiple USIDs arranged in sequence. The combination of BLOCK and the first USID constitutes the SID corresponding to the first USID. Therefore, the determined next-hop network device is the network device corresponding to the first USID.
  • the network device S queries the local routing table according to the longest matching rule according to the content in the DA field in the header of the message. Specifically, the part composed of BLOCK+USID1 is A:1:01:11, which is matched with the entries in the routing table, and is successfully matched with SID1, that is, network device S determines that the next hop network device is network device 1, thus The message including the segment list is sent to the network device 1.
  • the network device 1 After receiving the message, the network device 1 queries the local segment identification table (local SID table) according to the longest matching rule according to the content of the DA field, and determines the message processing action.
  • the DA field includes a BLOCK and multiple USIDs arranged in sequence. The combination of the BLOCK and the first USID constitutes the SID corresponding to the first USID. Therefore, the determined message processing action is the message processing action corresponding to the functional field in the first USID, and can also be referred to as the message processing action corresponding to the first USID.
  • a message including a segment list is sent by network device S to network device 1, and network device 1 according to the DA field in the message
  • the longest matching rule queries the local segment identification table, and the part consisting of BLOCK+USID1 matches the entry in the local segment identification table successfully, and the network device 1 executes the packet forwarding processing action corresponding to the USID1.
  • the message forwarding processing action may include updating the DA field. Specifically, the network device 1 deletes a bit of USID length in the part after the BLOCK in the DA field, moves the remaining part forward, and fills all 0s in the blank part at the end.
  • the network device 1 further determines whether the part after the BLOCK in the DA field is all 0. If it is not all 0, the network device 1 queries the local routing table according to the longest matching rule according to the content in the DA field, and continues to forward the message.
  • the processing actions of the other intermediate nodes on the message may be the same as the foregoing message processing actions of the network device 1. That is to say, the processing actions of the multiple intermediate nodes on the forwarding path to the message all include updating the DA field and judging whether the part after the BLOCK in the DA field is all 0.
  • the network device 1 is updating the DA field, the USID1 after the BLOCK in the DA field is deleted, the rest moves forward, and the blank part at the end is filled with all 0s.
  • the DA field includes BLOCK, USID2, and USID3, and the structure of the message is shown in FIG. 11.
  • the network device 1 judges that the part after the BLOCK in the DA field is not all 0, and then continues to forward the message.
  • the content of the DA field successfully matches the SID of the network device 2 according to the longest matching rule, that is, the part composed of BLOCK+USID2 matches the SID of the network device 2 successfully, and the network device 1 sends the message to the network device 2.
  • the network device 2 queries the local segment identification table according to the longest matching rule according to the DA field in the message, and the part consisting of BLOCK+USID2 is matched successfully, and the corresponding message processing action is executed.
  • the network device 2 updates the DA field, that is, deletes the USID2 in the DA field, moves the remaining part forward, and fills all 0s in the blank at the end.
  • the DA field includes BLOCK and USID3, and the structure of the message is shown in FIG. 12. The network device 2 judges that the part after the BLOCK in the DA field is not all 0, and then continues to forward the message.
  • the content of the DA field successfully matches the SID of the network device 3 according to the longest matching rule, that is, the part composed of BLOCK+USID3 matches the SID of the network device 3 successfully, and the network device 2 sends the message to the network device 3.
  • the network device 3 receives the message.
  • the network device 3 further determines that there is a remaining identifier after the BLOCK in the DA field. If there is no remaining identifier, for example, the part after the BLOCK is all 0, then the network Device 3 needs to continue to copy the ID to the DA field.
  • the network device performing the copy action may be referred to as a copy node, that is, the network device 3 is a copy node.
  • the copy node determines the position of the first identifier in the first element according to the value of the first pointer.
  • the first pointer is the PI pointer
  • the first identifier is the identifier currently to be added.
  • the network device 3 first determines the current element according to the value of the SL pointer. The network device 3 then determines the current identifier to be added in the current element according to the value of the PI pointer. Determine the current identifier to be added according to the value of the PI pointer. The current identifier to be added is the first identifier.
  • the network device 3 queries the local segment identification table according to the longest matching rule according to the DA field in the message, and the part consisting of BLOCK+USID3 matches successfully and executes the corresponding forwarding action.
  • the network device 3 updates the DA field, that is, deletes the USID3 in the DA field, moves the remaining part forward, and fills all 0s in the blank at the end.
  • only BLOCK is included in the DA field.
  • the network device 3 judges that the part after the BLOCK in the DA field is all 0, that is, it needs to add the USID to the DA field.
  • the network device 3 determines the current element according to the value of the SL pointer.
  • the value of the SL pointer in the message may be 4, and the network device 3 determines that the current element is the first element in the segment list. Furthermore, the network device 3 determines that the current identifier to be added is the fourth USID in the current element, that is, USID4, according to the value of the PI pointer of 3.
  • the copy node copies at least one identifier starting from the first identifier to the header of the first message.
  • the packet header may be an IPv6 packet header.
  • the copy node determines the number of the at least one USID.
  • the copy node determines the integer part of (128-L BLOCK )/L USID, and uses the value of the integer part as the quantity of the at least one USID.
  • the copy node compares the integer part of (128-L BLOCK )/L USID and the number of remaining USIDs in the current element that are not added to the DA field, and uses the smaller value of the two as the value of the at least one USID Quantity.
  • the copy node modifies the value of the PI pointer in the message so that the value of the PI pointer after the modification points to the current identifier to be added in the segment list.
  • the identifier to be added may be referred to as a third identifier, and the third identifier may be the next identifier of the last USID in the at least one USID in the segment list.
  • the identifier to be added may be a USID, which is located in the next element of the current element in the segment list, that is, all USIDs in the current element have been added to the DA field.
  • the USID may be the first USID in the latter element.
  • the value of the modified PI pointer is used to indicate the position of the USID in the latter element.
  • the value of the modified PI pointer may be 0.
  • the copy node modifies the value of the SL pointer in the message so that the modified value of the SL pointer points to the next element of the current element in the segment list .
  • the network device 3 determines that the identifier currently to be added is USID4. In addition, the network device 3 determines that the number of remaining USIDs that are not added to the DA field in the current element is 1, that is, there is only USID4. Since the length of the USID is 32 bits and the length of the BLOCK is 32 bits, the integer part of (128-L BLOCK )/L USID is 3, which is greater than the number of remaining USIDs. Therefore, the network device 3 determines that the number of at least one USID to be added to the DA field is one. The network device 3 adds the USID4 to the DA field of the IPv6 header of the message, and the message structure at this time is shown in FIG. 14.
  • the network device 3 modifies the value of the SL pointer in the message by subtracting the value of the SL pointer by 1, and the modified value of the SL pointer is 3, pointing to the segment list The second element in.
  • the network device 3 modifies the value of the PI pointer, and the modified PI pointer value is 0, which points to the first USID in the second element, that is, USID5.
  • the network device 3 sends the message.
  • the message continues to be forwarded along the forwarding path, and the intermediate node on the forwarding path continues to update the DA field in the message.
  • the copy node on the forwarding path continues to update the DA field in the message. For example, after at least one USID added in the DA field is processed, the copy node will continue to add at least one identifier starting from the current identifier to be added to the DA field of the message according to the value of the PI pointer.
  • the at least one identifier starting from the current identifier to be added may be a USID.
  • the processing procedure of the copy node is similar to the above description, and will not be repeated here.
  • the at least one USID is multiple USIDs.
  • the at least one USID is a plurality of USIDs, the plurality of USIDs are adjacent to each other in the segment list.
  • the copy node modifies the value of the PI pointer in the message, so that the value of the PI pointer after the modification points to the identifier currently to be added.
  • the current to be added The identifier of is the next identifier of the last USID in the at least one USID in the segment list.
  • the currently to-be-added identifier may be a USID, and both the USID and the at least one USID may be located in the current element.
  • the value of the modified PI pointer is used to indicate the position of the USID in the current element.
  • the currently to-be-added identifier may be a USID, which is located in the next element of the current element in the segment list, that is, all USIDs in the current element have been added to the DA field.
  • the USID may be the first USID in the latter element.
  • the value of the modified PI pointer is used to indicate the position of the USID in the latter element.
  • the value of the modified PI pointer may be 0.
  • the copy node modifies the value of the SL pointer in the message so that the modified value of the SL pointer points to the next element of the current element in the segment list .
  • the network device 4 receives the message, and processes the message according to BLOCK+USID4 in the DA field. In addition, the network device 4 updates the DA field, deletes the USID4 in the DA field, moves the remaining part forward, and fills all 0s in the blank part at the end. At this time, only BLOCK is included in the DA field. Then the network device 4 is a copy node. The network device 4 judges that the part after the BLOCK in the DA field is all 0, and the network device 4 continues to add an identifier to the DA field of the message.
  • the network device 4 determines that the current element is the second element in the segment list according to the value of the SL pointer in the message, and determines that the current identifier to be added is the first USID in the second element according to the value of the PI pointer, that is, USID5 .
  • the network device 4 determines that the integer part of (128-L BLOCK )/L USID is 3, determines that the number of remaining USIDs that are not added to the DA field in the current element is 4, and uses the smaller value of the two, that is, 3 as the addition To the number of USIDs in the DA field.
  • the network device 4 adds three USIDs starting with USID5 to the DA field, and the three USIDs are USID5, USID6, and USID7.
  • the message structure at this time is shown in FIG. 15.
  • the network device 4 modifies the value of the PI pointer so that the value of the PI pointer points to the USID to be added, that is, USID8.
  • the message continues to be forwarded to the network device 8 through the network device 5, the network device 6, and the network device 7.
  • the message processing actions of these network devices are similar to those of the network device 1, the network device 2, the network device 3, and the network device 4.
  • the network device 7 is also a copy node, which will not be repeated here.
  • the at least one identifier starting from the current identifier to be added may be an SID with a length of 128 bits.
  • the prompt identifier is included in the previous USID of the SID in the segment list.
  • the copy node processes the previous USID, it can determine that the next identifier of the USID is an SID with a length of 128 bits according to the prompt flag.
  • the copy node adds an SID with a length of 128 bits to the DA field of the message. In other words, the BLOCK part in the DA field will also be covered.
  • the copy node modifies the value of the PI pointer in the message, so that the value of the PI pointer after the modification points to the identifier currently to be added.
  • the current to be added The identifier of is the next identifier of the last USID in the at least one USID in the segment list.
  • the currently to-be-added identifier may be an SID with a length of 128 bits.
  • the SID occupies all the space in an element, for example, the value of the PI pointer after modification may be 0.
  • the network device 8 is also a copy node.
  • the network device 8 receives the message, processes the message according to the BLOCK+USID8 in the DA field, finds that the USID8 includes a prompt flag, and determines that the next identifier of the USID8 in the segment list is an SID with a length of 128 bits.
  • the network device 8 determines that the current element is the third element in the segment list according to the value of the SL pointer in the message, and adds the SID in this element to the DA field, that is, adds SID9 to the DA field.
  • the message structure at this time is As shown in Figure 16.
  • the message may only include the XL pointer.
  • the network device S adds at least one identifier to the DA field, and the identifier may be a USID.
  • the copy node determines the position of the first identifier in the segment list according to the value of the XL pointer, and copies at least one identifier starting from the first identifier to the header of the first message. Specifically, The copy node adds at least one identifier starting from the first identifier to the DA field.
  • the copy node modifies the value of the XL pointer in the message, so that the modified value of the XL pointer still points to the current identifier to be added in the segment list.
  • at least one identifier starting from the first identifier is an identifier, that is, the first identifier, that is, each time it is added to the DA field
  • the number of identifiers in can be one, and the position pointed to by the XL pointer in the segment list is offset by the length of one identifier at a time.
  • the network device S adds the BLOCK part of the SID in the DA field, and after the BLOCK in the DA field, adds 1 USID, that is, USID1.
  • the value of the XL pointer can be modified before or after the USID is added.
  • the network device S sets the XL pointer in the message to point to USID2, which indicates that the current identifier to be added is USID2 in the segment list.
  • the network device S queries the local routing table according to the longest matching rule according to the content in the DA field in the message header of the message.
  • the part composed of BLOCK+USID1 is A:1:01:11, which is matched with the entries in the routing table, and is successfully matched with SID1, that is, network device S determines that the next hop network device is network device 1, thus The message including the segment list is sent to the network device 1.
  • network device 1 queries the local segment identification table according to the longest matching rule. If the part consisting of BLOCK+USID1 matches the entry in the local segment identification table successfully, then network device 1 executes the corresponding USID1 Message processing action.
  • the network device corresponding to each identifier in the segment list is a copy node, that is, the network device 1 is also a copy node.
  • the network device 1 determines the position of the currently to be added USID2 in the segment list according to the value of the XL pointer, and copies the USID2 into the DA field.
  • the network device 1 modifies the value of the XL pointer in the message, and the modified XL pointer points to USID3, that is, indicates that the current identifier to be added is USID3 in the segment list.
  • the message continues to be forwarded to network device 10 through network device 3, network device 4, network device 5, network device 6, network device 7, network device 8, and network device 9.
  • the message processing actions of these network devices are respectively the same as those of network devices.
  • the device 1 is similar and will not be repeated here.
  • the segment list can include USID and other types of identifiers at the same time.
  • the other type of identification may be an MPLS label or an IPv4 address, that is to say, an MPLS label or an IPv4 address may also be mixed in the list of segments using the USID.
  • some network devices may not support SRv6, but can support MPLS, or can support IPv4.
  • the segment list directly stores the MPLS labels or IPv4 addresses corresponding to these network devices . Thereby, network compatibility is improved, and network efficiency is improved.
  • the network device S sends a message to the network device 10, and the forwarding path of the message sequentially passes through the network device 1, the network device 2, the network device 3, the network device 4, the network device 5, and the network device 6. , Network equipment 7, network equipment 8, network equipment 9. Among them, network device 3, network device 4, network device 5, and network device 6 do not support SRv6, but can support MPLS.
  • the USID and MPLS label and/or IPv4 address are arranged in sequence according to the order of the corresponding network device on the forwarding path.
  • the length of each MPLS label can be 32 bits, and the length of each IPv4 address can also be 32 bits.
  • the length of the MPLS label or IPv4 address can be the same as the length of the USID, or it can be different from the length of the USID.
  • Figure 8 shows the structure of the segment list at this time. Since network equipment 3, network equipment 4, network equipment 5, and network equipment 6 do not support SRv6, but can support MPLS, the segment list can be stored corresponding to these network equipment.
  • MPLS labels namely M3, M4, M5 and M6.
  • the segment list also stores the USID or SID corresponding to other network devices.
  • the length of the MPLS label is 32 bits, which is the same length as the USID.
  • these MPLS labels can be stored in one element with the USID. As shown in Figure 8, the first element in the segment list contains USID1, USID2, M3 and M4, and the second element stores M5, M6, USID7 and USID8. .
  • the storage method of IPv4 addresses is similar to that of MPLS labels, so I won't repeat them here.
  • the network device S adds a handover flag to the message, and the handover flag may be located in the segment list.
  • the handover flag may be located in a specific identifier in the segment list, and the specific identifier is called, for example, the second identifier.
  • the second identifier may be in the previous USID of the first MPLS label or IPv4 address.
  • the handover flag may be an independent identifier that is added between the last USID and the first MPLS label or IPv4 address.
  • the switch flag is used to indicate that the next identifier in the segment list will include the MPLS label and/or IPv4 address, so that when the network device reads the previous USID, it can determine that the USID is at the end of the segment list.
  • An identifier will include an MPLS label and/or IPv4 address. The specific process will be described in detail below.
  • the network device S when the network device S adds at least one identifier to the DA field, the network device S will determine whether each of the added at least one identifier includes the handover flag, and if a certain identifier includes Switching the flag, the network device S will not add the last flag of this flag to the DA field after adding this flag to the DA field.
  • at least one identifier added to the DA field is all USID, and does not include other types of identifiers.
  • the network device S when the segment list includes MPLS labels and/or IPv4 addresses, the network device S also adds a quantity flag to the message, and the value of the quantity flag is used to indicate the number of MPLS labels and/or IPv4 addresses in the segment list .
  • the position of the quantity indicator may be in the message header, and the message header may be an SRH or an IPv6 message header.
  • the quantity flag may be located in a specific field of the SRH, or the quantity flag may be located in the DA field of the IPv6 packet header.
  • the quantity flag can also be located in the segment list.
  • the quantity indicator when the segment list includes consecutively arranged multiple MPLS labels or IPv4 addresses, the quantity indicator may be located in the previous USID of the first MPLS label or IPv4 address.
  • the PI pointer is used to indicate the positions of different USIDs, MPLS labels or IPv4 addresses in this element.
  • the switching flag and the number flag may be the same flag, that is, the number flag also functions as a switching flag.
  • the segment list includes multiple MPLS labels or IPv4 addresses arranged consecutively, and the number flag may be located in the previous USID of the first MPLS label or IPv4 address.
  • FIG. 10 shows the structure of the message with the segment list and PI pointer added, and the segment list includes the MPLS label.
  • the network device S adds the BLOCK part of the SID to the DA field. After the BLOCK in the DA field, add 2 USIDs and 1 MPLS label. As shown in Figure 10, two USIDs are USID1 and USID2, and one MPLS label is M3.
  • the value of the PI pointer is 3, which means that the first 3 identifiers in this element of the segment list have been added to the DA field. According to the value of the PI pointer, the identifier to be added in the element, namely M3, can be determined, and the specific content will be described in detail below.
  • intermediate nodes on the forwarding path can copy other types of identifiers to the forwarding identifier stack in the message, and the forwarding identifier The stack is used to guide message forwarding.
  • the intermediate node that performs the above copy behavior may be called a copy node.
  • the copy node on the forwarding path processes the current USID, it can determine that the latter identifier in the segment list will include the MPLS label or the IPv4 address through the above-mentioned switching flag or the number flag. At this time, the current identifier to be added should be the first MPLS label or IPv4 address. The copy node then determines the first MPLS label or IPv4 address according to the value of the PI pointer.
  • the copy node can directly determine the first MPLS label or IPv4 address in the segment list according to the value of the PI pointer.
  • the copy node may respectively obtain other identifiers that have been added to the DA field and other identifiers that have not been added to the DA field.
  • the copy node can also determine the number N of MPLS labels or IPv4 addresses that have been added to the DA field, where N is an integer, and then the value of the PI pointer can be corrected according to the value of the PI pointer and the number N.
  • the value of the subsequent PI pointer determines the first MPLS label or IPv4 address in the segment list. Specifically, the copy node corrects the value of the PI pointer by subtracting the value of the number N from the value of the PI pointer.
  • the above process can also be regarded as the rollback of the PI pointer in the segment list.
  • the DA field in the message includes BLOCK, USID2, and M3, and the USID2 includes a quantity flag, and the value of the quantity flag can be 4.
  • the value of the PI pointer in the message can be 3.
  • the foregoing copy node may be the network device 2.
  • the network device 2 queries the local segment identification table according to the longest matching rule according to the DA field in the message, the part consisting of BLOCK+USID2 matches successfully, and executes the corresponding forwarding action.
  • the network device 2 processes the current USID2, it is determined by the number flag included in the USID2, the USID2 will include the MPLS label in the latter identifier in the segment list, and the number of MPLS labels is 4. At this time, the current identifier to be added should be the first MPLS label.
  • Network device 2 determines that the current USID2 is not the last USID in the DA field, there are 32 non-zero bits after USID2 in the DA field, and there is an MPLS label after USID2, which means that the first MPLS label has been added To the DA field.
  • the network device 2 determines that the value of the PI pointer after the correction should be 2 according to the value of the PI pointer of 3 and the number of MPLS labels that have been added to the DA field as 1.
  • the first An MPLS label should be the third identifier in the current element, that is, M3.
  • the copy node when the at least one identifier starting from the first identifier is at least one other type of identifier, such as an MPLS label or an IPv4 address, the copy node adds these other types of identifiers to the second message
  • the header is used to form a forwarding identification stack, such as an MPLS label stack or an IPv4 address stack.
  • the copy node can obtain other identifiers that have been added to the DA field and other identifiers that have not been added to the DA field. , And add the other identifiers of these two parts to the second message header to form a forwarding identifier stack; optionally, the copy node can also determine the first one in the segment list according to the value of the corrected PI pointer. The location of other types of identifiers to obtain all other types of identifiers from the segment list.
  • the copy node determines the number of the at least one MPLS label or IPv4 address.
  • the intermediate node uses the value of the quantity flag as the quantity of the at least one MPLS label or IPv4 address.
  • the at least one MPLS label or IPv4 address corresponds to at least one network device supporting MPLS or IPv4.
  • the message may enter the SRv6 network again.
  • these USIDs can be copied into the DA field by the intermediate node.
  • these USIDs can also be copied into the DA field by the last network device among the at least one network device supporting MPLS or IPv4.
  • the copy node modifies the value of the PI pointer in the message to make the value of the PI pointer after modification It points to other identifiers in the segment list, and this other identifier may be called a third identifier, for example.
  • the third identifier may be the next identifier in the segment list of the last USID among the above-mentioned USIDs copied into the DA field.
  • the third identifier may be located in the same element in the segment list as the last USID, or may be located in a different element in the segment list from the last USID.
  • the first element and the second element may be the same or different.
  • the copy node also modifies the value of the SL pointer in the message, so that the modified SL pointer points to the second element.
  • the second element may be the next element of the first element in the segment list.
  • the above-mentioned copy node may be the network device 2, and the structure of the message received by the network device 2 is shown in FIG. 13.
  • the network device 2 determines that the first MPLS label should be the third identifier in the current element, that is, M3.
  • the network device 2 determines that the number of the at least one MPLS label to be added to the DA field is 4 according to the value of the number flag.
  • the network device 2 establishes an MPLS packet header outside the IPv6 packet header of the packet, and the MPLS packet header includes a forwarding identification stack, that is, an MPLS label stack.
  • the network device 2 adds 4 MPLS labels starting with M3 to the MPLS label stack.
  • the 4 MPLS labels include M3, M4, M5, and M6.
  • the network device 2 copies at least one USID after M6 in the segment list into the DA field. Specifically, the network device 2 copies USID7 and USID8 into the DA field.
  • network device 2 modifies the value of the SL pointer, the value of the modified SL pointer is 2, which points to the third element in the segment list, and the network device 2 modifies the value of the PI pointer, and the value of the modified PI pointer is 0. Point to the first identifier in the third element, namely SID9. At this time, the structure of the message is shown in Figure 17.
  • the network device 2 forwards the message to the network device 3 according to the top label of the MPLS label stack in the MPLS message header, that is, M3.
  • M3 on the top of the MPLS label stack is popped out, and M4 becomes the label on the top of the stack.
  • the network device 3 forwards the message to the network device 4 according to M4.
  • the message then arrives at the network device 4, the network device 5, and the network device 6 in sequence.
  • the specific process is similar to the above description, and will not be repeated here.
  • the MPLS header in the message is stripped.
  • the network device 6 supports both MPLS and SRv6.
  • the network device 6 continues to forward the message according to the DA field in the IPv6 header of the message. Referring to the message structure shown in FIG. 17, the DA field includes BLOCK, USID7, and USID8. Thus, the network device 6 forwards the message to the network device 7.
  • the specific process is similar to the above description, and will not be repeated here.
  • the above is an example of the processing procedure of the MPLS label.
  • the processing procedure of the IPv4 address is similar to the above description, and will not be repeated here.
  • the embodiment of the present invention provides a method for forwarding a message.
  • Figure 18 shows a method flow chart of this method.
  • the method involves a network device 401 and a network device 402.
  • the network device 401 may be a network entry device in the network, and is used to encapsulate the segment list of the forwarding path of the corresponding message in the message, for example, the network device S shown in FIG. 1.
  • the network device 402 may be a forwarding device in the network.
  • the network device 402 is the copy node in the above-mentioned embodiment, for example, the network device 3, the network device 4, the network device 7, the network device 8 or the network device shown in FIG. Device 9, or, network device 2 shown in Figure 1.
  • the steps of the method include:
  • S410 The network device 401 receives the message.
  • the network device 401 obtains the segment list.
  • the segment list corresponds to the forwarding path of the first packet, the forwarding path includes a plurality of network devices, the segment list includes a plurality of identifiers arranged in sequence, and the identifiers in the plurality of identifiers correspond to the A network device among a plurality of network devices or a link in the forwarding path, the segment list includes an element with a length of 128 bits, and the element includes at least two adjacent identifiers among the plurality of identifiers .
  • the network device 401 adds the segment list to the message, the segment list includes a first pointer, the value of the first pointer is used to indicate the position of the first identifier in the element, and the first identifier is Said at least one of the two logos.
  • the network device 401 may be a network entry device in the network, and the network device 401 is an entry node of the forwarding path of the packet, for example, the network device S shown in FIG. 1.
  • the network device S shown in FIG. 1.
  • the network device 402 receives the message.
  • the message header of the message includes a list of segments for forwarding the message, and the segment list includes a plurality of identifiers arranged in sequence, and each identifier of the plurality of identifiers corresponds to a network device or a network device.
  • the segment list includes a first element with a length of 128 bits, the first element includes at least two adjacent identifiers among the plurality of identifiers, and the first message includes a first pointer.
  • the network device 402 determines the position of the first identifier in the first element according to the value of the first pointer.
  • S470 The network device 402 copies at least one identifier starting from the first identifier into a header of the message.
  • S480 The network device 402 sends the message.
  • the network device 402 may be a copy node of the forwarding path of the message, that is, the network device 402 is an intermediate node that copies at least one identifier to the message.
  • the at least one identifier copied by the network device 402 may be a USID, an MPLS label or an IPv4 address.
  • the network device 402 may be the network device 2, the network device 3, the network device 4, the network device 7, the network device 8 or the network device 9 in 1.
  • the network device 2 refer to the description of the network device 2, the network device 3, the network device 4, the network device 7, the network device 8 or the network device 9 in the foregoing embodiment, and the similarities are not repeated here.
  • the forwarding path of the message can be generated by the controller or the ingress node of the forwarding path.
  • the controller When the controller generates the forwarding path of the message, the controller will also generate a segment list corresponding to the forwarding path, and the segment list may be a segment list including the USID.
  • the controller sends the segment list to the entry node of the forwarding path.
  • the ingress node of the forwarding path After receiving the message, the ingress node of the forwarding path determines the forwarding path of the message from the several forwarding paths stored in the device, and determines the segment list corresponding to the forwarding path. Encapsulate the segment list into the message for forwarding the message.
  • the embodiment of the present invention provides a method for forwarding a message.
  • Figure 19 shows a method flow chart of this method.
  • the method involves network device 301, network device 302, and network device 303.
  • the network device 301 may be a controller in the network, which is used to calculate the forwarding path of the packet and generate a segment list corresponding to the forwarding path.
  • the network device 302 may be a network entry device for encapsulating a segment list in a message, for example, the network device S shown in FIG. 1.
  • the network device 303 may be a forwarding device in the network for forwarding packets according to the segment list.
  • the network device 303 may be the copy node in the above-mentioned embodiment, for example, the network device 2, the network device 3, and the network device 3 shown in FIG. Network device 4, network device 7, network device 8, or network device 9.
  • the steps of the method include:
  • the network device 301 determines a packet forwarding path, where the forwarding path includes multiple network devices.
  • the network device 301 may be a controller in the network.
  • the controller calculates the forwarding path used to forward the message.
  • the network device 301 generates the segment list corresponding to the forwarding path, the segment list includes the plurality of identifiers arranged in sequence, and each identifier of the plurality of identifiers corresponds to the plurality of networks respectively.
  • the network device 301 obtains multiple segment identifiers, and the multiple segment identifiers correspond to at least one network device of the multiple network devices or at least one link in the forwarding path.
  • the controller obtains the SID of each network device on the forwarding path.
  • the network device 301 obtains multiple identifiers according to the multiple segment identifiers, and the multiple identifiers are mapped to the multiple segment identifiers one by one.
  • the controller can convert multiple SIDs into multiple USIDs, and multiple USIDs are mapped to multiple SIDs one by one. Specific methods include omitting the BLOCK part of the SID and/or setting the function field of the SID to a compressed format. For the specific process, refer to the description of step S420, and the similarities will not be repeated.
  • the network device 301 generates the segment list corresponding to the forwarding path, the segment list includes the plurality of identifiers arranged in sequence, the segment list includes an element with a length of 128 bits, and the element includes the plurality of identifiers. At least two adjacent marks in the marks. For example, the controller puts multiple USIDs instead of multiple SIDs into the segment list, thereby reducing the length of the segment list.
  • the space in the segment list can be divided into multiple elements, and the length of each element can be 128 bits. At least two USIDs can be stored in each element. For the specific process, refer to the description of step S420, and the similarities will not be repeated.
  • S320 The network device 301 sends the segment list to the network device 302.
  • the network device 302 is a network device in the network, and the network device 302 is an entry node of the forwarding path of the message, for example, the network device S shown in FIG. 1.
  • the network device 302 obtains a segment list, the segment list corresponding to the forwarding path of the message, and the segment list includes a plurality of identifiers arranged in sequence, and each identifier of the plurality of identifiers corresponds to one of the plurality of network devices Of a network device.
  • S325 The network device 302 receives the message.
  • the network device 302 receives the message and determines the forwarding path of the message.
  • the network device 302 may find a forwarding path for forwarding the message from a plurality of stored forwarding paths, so as to determine the forwarding path of the message.
  • the stored multiple forwarding paths may be received by the network device 302 from the controller.
  • the network device 302 adds the segment list to the message, the segment list includes the first pointer, and the value of the first pointer is used to indicate the position of the first identifier in the element.
  • An identifier is one of the at least two identifiers.
  • step S330 For the specific process of step S330, reference may be made to the description of step S430, and the similarities will not be repeated.
  • S335 The network device 302 sends the message.
  • step S33 For the specific process of step S335, refer to the description of step S440, and the similarities will not be repeated.
  • S340 The network device 303 receives the message.
  • step S340 For the specific process of step S340, reference may be made to the description of step S450, and the similarities will not be repeated.
  • the network device 303 determines the position of the first identifier in the first element according to the value of the first pointer.
  • the first pointer is the newly added PI pointer described above.
  • step S345 For the specific process of step S345, reference may be made to the description of step S460, and the similarities will not be repeated.
  • the network device 303 copies at least one identifier starting from the first identifier into a header of the message.
  • step S350 For the specific process of step S350, refer to the description of step S470, and the similarities will not be repeated.
  • step S355 For the specific process of step S355, refer to the description of step S480, and the similarities will not be repeated.
  • FIG. 20 is a schematic structural diagram of a device 400 provided by an embodiment of the present application. Any network device in Figure 1 can be implemented by the device shown in Figure 20.
  • the network device 401 and the network device 402 in the embodiment shown in FIG. 18, and the network device 301, the network device 302, and the network device 303 in the embodiment shown in FIG. 19 may be implemented by the device shown in FIG. 20.
  • the device 2000 includes at least one processor 2001, a communication bus 2002, and at least one communication interface 2004.
  • the device 2000 may further include a memory 2003.
  • the processor 2001 and the processor 1502 can be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), and an on-site A field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute various logical blocks, modules, and circuits described in conjunction with the disclosure of the embodiments of the present invention.
  • the processor may also be a combination for realizing computing functions, for example, including a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on. .
  • the processor can be used to generate a list of segments, or process the received message, and continue to forward the processed message through the communication interface. To implement the method provided in the embodiment of the present application.
  • the processor can be used to generate a segment list, so that the network device can forward the corresponding message according to the segment list.
  • the processor can be used to add a segment list to the received message, so that subsequent network devices can follow the segment list in the message The message is forwarded, and the specific function implementation can refer to the processing part of the network entrance device in the method embodiment.
  • the forwarding device in the network in FIG. 1 is implemented by the device shown in FIG. 20
  • the processor can be used to forward the message according to the segment list in the message
  • the specific function implementation can refer to the method implementation The processing part of the forwarding device in the example.
  • the communication bus 2002 is used to transfer information between the processor 2001, the communication interface 2004, and the memory and 2003.
  • the bus may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus.
  • PCI peripheral component interconnect
  • EISA extended industry standard architecture
  • the bus can be divided into an address bus, a data bus, a control bus, and so on. For ease of presentation, only one thick line is used to represent in FIG. 20, but it does not mean that there is only one bus or one type of bus.
  • the memory 2003 can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM), or other types that can store information and instructions
  • the dynamic storage device can also be electrically erasable programmable read-only memory (EEPROM), compact disc read-only Memory (CD-ROM) or other optical disc storage, optical disc storage (Including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or can be used to carry or store desired program codes in the form of instructions or data structures and can be used by a computer Any other media accessed, but not limited to this.
  • the memory 2003 may exist independently, and is connected to the processor 2001 through a communication bus 2002.
  • the memory 403 may also be integrated with the processor 2001.
  • the memory 2003 is used to store program codes or instructions for executing the solutions of the present application, and the processor 2001 controls the execution.
  • the processor 2001 is configured to execute the program code stored in the memory 2003.
  • One or more software modules can be included in the program code.
  • the processor 2001 itself may also store program codes or instructions for executing the solutions of the present application.
  • the communication interface 2004 uses any device such as a transceiver to communicate with other devices or communication networks.
  • the communication network may be Ethernet, wireless access network (RAN), or wireless local area networks (WLAN).
  • the communication interface 2004 may be used to receive messages sent by other nodes in the segment routing network, and may also send messages to other nodes in the segment routing network.
  • the communication interface 2004 may be an Ethernet interface (Ethernet) interface, a Fast Ethernet (FE) interface, a Gigabit Ethernet (GE) interface, or an asynchronous transfer mode (Asynchronous Transfer Mode, ATM) interface.
  • the device 2000 may include multiple processors, such as the processor 2001 and the processor 2005 shown in FIG. 20.
  • processors can be a single-CPU (single-CPU) processor or a multi-core (multi-CPU) processor.
  • the processor here may refer to one or more devices, circuits, and/or processing cores for processing data (for example, computer program instructions).
  • FIG. 21 is a schematic structural diagram of a device 2100 provided by an embodiment of the present application. Any network device other than the controller in FIG. 1 can be implemented by the device shown in FIG. 21.
  • the network device 401 and the network device 402 in the embodiment shown in FIG. 18, and the network device 302 and the network device 303 in the embodiment shown in FIG. 19 may be implemented by the device shown in FIG. 21.
  • the device 2100 includes a main control board and one or more interface boards, and the main control board is in communication connection with the interface board.
  • the main control board is also called the main processing unit (MPU) or the route processor card.
  • MPU main processing unit
  • the main control board is responsible for the control and management of each component in the device 2100, including routing calculation, device management and maintenance functions .
  • the interface board is also called a line processing unit (LPU) or a line card (line card), and is used to forward data.
  • the device 2100 may also include a switching network board.
  • the switching network board is in communication connection with the main control board and the interface board.
  • the switching network board is used to forward data between the interface boards.
  • the switching network board may also be called a switching network. Board unit (switch fabric unit, SFU).
  • the interface board includes a central processing unit, a memory, a forwarding chip, and a physical interface card (PIC).
  • the central processing unit is respectively communicatively connected with the memory, the network processor and the physical interface card.
  • the memory is used to store the forwarding table.
  • the forwarding chip is used to forward the received data frame based on the forwarding table stored in the memory. If the destination address of the data frame is the address of the device 2100, the data frame is sent to the CPU for processing; if the destination address of the data frame is not the address of the device 2100 Address, the next hop and outbound interface corresponding to the destination address are found from the forwarding table according to the destination address, and the data frame is forwarded to the outbound interface corresponding to the destination address.
  • the forwarding chip may be a network processor (NP).
  • the PIC is also called a daughter card, which can be installed on the interface board and is responsible for converting the photoelectric signal into a data frame and forwarding the data frame to the forwarding chip for processing after legality checking.
  • the central processing unit can also perform the function of a forwarding chip, such as realizing software forwarding based on a general-purpose CPU, so that no forwarding chip is required in the interface board.
  • the communication connection between the main control board, the interface board, and the switching network board can be realized through a bus.
  • the forwarding chip may be implemented by an application-specific integrated circuit (ASIC) or a field programmable gate array (FPGA).
  • the device 2100 includes a control plane and a forwarding plane.
  • the control plane includes a main control board and a central processing unit.
  • the forwarding plane includes various components that perform forwarding, such as memory, PIC, and NP.
  • the control plane performs functions such as routers, generation of forwarding tables, processing of signaling and protocol messages, configuration and maintenance of the state of PE1.
  • the control plane delivers the generated forwarding tables to the forwarding plane.
  • the NP is based on the control plane’s
  • the forwarding table looks up and forwards the message received by the PIC of the device 2100.
  • the forwarding table issued by the control plane can be stored in the memory. In some embodiments, the control plane and the forwarding plane may be completely separated and not on the same device.
  • FIG. 22 shows a schematic diagram of a possible structure of the network device involved in the foregoing embodiment.
  • the network device 1400 can implement the functions of the network device 402 or the network device 303 in the foregoing embodiment.
  • the network device 1400 includes: a receiving unit 1401, a processing unit 1402, and a sending unit 1403. These units can perform the corresponding functions of the network device 402 or the network device 303 in the foregoing method. for example,
  • the receiving unit 1401 is configured to receive a first message.
  • the first message header of the first message includes a segment list used to forward the first message, and the segment list includes a plurality of segments arranged in sequence.
  • the identifier in the plurality of identifiers corresponds to a network device or a link
  • the segment list includes a first element with a length of 128 bits
  • the first element includes adjacent ones of the plurality of identifiers. At least two identifiers
  • the first message includes a first pointer and a second pointer.
  • the processing unit 1402 is configured to determine the position of the first element in the segment list according to the value of the second pointer, and determine that the first identifier is in the first element according to the value of the first pointer
  • the first identifier is one of the at least two identifiers; the at least one identifier starting with the first identifier is copied to the second header of the first message to Generate the second message.
  • the sending unit 1403 is configured to send the second message.
  • the network device 1400 can also be implemented by the device shown in FIG. 20. At this time, the network device 1400 includes: at least one processor, a communication bus, and at least one communication interface. Optionally, the network device 1400 may further include a memory.
  • the processor in the network device 1400 is configured to receive a first message through a communication interface, and the first message header of the first message includes a list of segments used to forward the first message, so
  • the segment list includes a plurality of identifiers arranged in sequence, and each identifier of the plurality of identifiers corresponds to a network device or a link, and the segment list includes a first element with a length of 128 bits.
  • the element includes at least two adjacent identifiers among the plurality of identifiers, and the first message includes a first pointer; the first identifier in the first element is determined according to the value of the first pointer.
  • the first identifier is one of the at least two identifiers; at least one identifier starting with the first identifier is copied to the second header of the first message to generate The second message; the second message is sent through the communication interface 1503.
  • the processes S450, S460, S470, and S480 please refer to the detailed descriptions of the processes S340, S345, S350, and S355 in the foregoing embodiment, which will not be repeated here.
  • the communication interface in the network device 1400 is used for the network device 1400 to receive and send messages through the network system.
  • the specific process please refer to the detailed descriptions of S450, S480, S340, and S355 in the foregoing embodiment, which will not be repeated here.
  • the network device 1400 can also be implemented by the device shown in FIG. 21.
  • the network device 1400 includes a main control board and one or more interface boards, and the main control board is in communication connection with the interface board.
  • the main control board is in communication connection with the interface board.
  • FIG. 23 shows a schematic diagram of a possible structure of the network device involved in the foregoing embodiment.
  • the network device 1600 can implement the functions of the network device 401 or the network device 302 in the foregoing embodiment.
  • the network device 1600 includes: a receiving unit 1601, a processing unit 1602, and a sending unit 1603. These units can perform the corresponding functions of the network device 401 or the network device 302 in the above method. for example,
  • the receiving unit 1601 is configured to receive the first message.
  • the processing unit 1602 is configured to obtain a segment list, the segment list corresponding to a forwarding path of the first packet, the forwarding path includes a plurality of network devices, the segment list includes a plurality of identifiers arranged in sequence, the The identifier in the plurality of identifiers corresponds to a network device in the plurality of network devices or a link in the forwarding path, the segment list includes a first element with a length of 128 bits, and the first element includes At least two adjacent identifiers among the plurality of identifiers; adding the segment list to the first message to generate a second message, the second message including a first pointer, the first The value of the pointer is used to indicate the position of the first identifier in the first element, and the first identifier is one of the at least two identifiers.
  • the sending unit 1603 is configured to send the second message.
  • the network device 1600 can also be implemented by the device shown in FIG. 20.
  • the network device 1600 includes: at least one processor, a communication bus, and at least one communication interface.
  • the network device 1600 may further include a memory.
  • the processor in the network device 1600 is configured to receive a first message through a communication interface; obtain a segment list, the segment list corresponds to a forwarding path of the first message, and the forwarding path includes a plurality of A network device, the segment list includes a plurality of identifiers arranged in sequence, each of the plurality of identifiers corresponds to a network device of the plurality of network devices or a link in the forwarding path,
  • the segment list includes a first element with a length of 128 bits, and the first element includes at least two adjacent identifiers among the plurality of identifiers; the segment list is added to the first message to generate
  • the second message the second message includes a first pointer, the value of the first pointer is used to indicate the position of the first identifier in the first element, and the first identifier is the at least two One of the logos.
  • the second message is sent through the communication interface.
  • the detailed processing process of the processor please refer to the detailed descriptions of the processes S410, S420, and S430 and the processes S325, S330, and S335 in the foregoing embodiment, which will not be repeated here.
  • the communication interface in the network device 1600 is used for the network device 1600 to receive and send messages through the network system.
  • the network device 1600 can also be implemented by the device shown in FIG. 21.
  • the network device 1600 includes a main control board and one or more interface boards, and the main control board is in communication connection with the interface board.
  • the main control board is in communication connection with the interface board.
  • FIG. 24 shows a schematic diagram of a possible structure of the network device 301 involved in the foregoing embodiment.
  • the network device 1800 can implement the functions of the network device 301 or the network device 401 in the foregoing embodiment.
  • the network device 1800 includes: a determining unit 1801 and a processing unit 1802. These units can perform the corresponding functions of the network device 301 or the network device 401 in the foregoing method. for example,
  • the determining unit 1801 is configured to determine a forwarding path of a packet, where the forwarding path includes multiple network devices.
  • the processing unit 1802 is configured to generate the segment list corresponding to the forwarding path, where the segment list includes the plurality of identifiers arranged in sequence, and each identifier of the plurality of identifiers corresponds to the plurality of identifiers respectively.
  • the network device 1800 further includes: a sending unit 1803.
  • the sending unit 1803 is configured to send the segment list to the entry device of the forwarding path.
  • the processing unit 1802 is further configured to encapsulate the segment list into a message; the sending unit 1803 is configured to send the message.
  • the network device 1800 can also be implemented by the device shown in FIG. 20. At this time, the network device 1800 includes: at least one processor, a communication bus, and at least one communication interface. Optionally, the network device 1800 may further include a memory.
  • the processor in the network device 1800 is configured to determine a forwarding path of a packet, the forwarding path includes multiple network devices; and the segment list corresponding to the forwarding path is generated, and the segment list includes successively The plurality of identifiers arranged, each of the plurality of identifiers respectively corresponds to a network device of the plurality of network devices or a link in the forwarding path, and the segment list includes a length of A 128-bit first element, where the first element includes at least two adjacent identifiers among the plurality of identifiers.
  • the processor in the network device 1800 is further configured to send the segment list through a communication interface.
  • the communication interface in the network device 1800 is used for the network device 1900 to receive and send information through the network system.
  • the specific process please refer to the detailed description of S320 and S420 in the foregoing embodiment, which will not be repeated here.
  • FIG. 25 shows a schematic diagram of a possible structure of a network system provided by an embodiment of the present invention.
  • the network system 2200 includes a first network device 2201 and a second network device 2202.
  • the first network device 2201 in the network system can execute the processing steps S410, S420, S430, S440 of the network device 401 in the embodiment shown in FIG. 18, or the processing steps of the network device 302 in the embodiment shown in FIG. 19 S325, S330, S335.
  • the second network device 2202 in the network system can execute the processing steps S450, S460, and S470 of the network device 402 in the embodiment shown in FIG. 20, or the processing steps S340, S345, and S350 of the network device 303.
  • the network system 2200 further includes a third network device 2203.
  • the first network device 2203 in the network system can execute the processing steps S310, S315, and S320 of the network device 301 in the embodiment shown in FIG. 19 above.
  • the first network device 2201 in the network system may be the network device 1600 in the embodiment shown in FIG. 23, and the second network device 2202 in the network device may be the network device in the embodiment shown in FIG. 22 Device 1400, the third network device 2203 in the network devices may be the network device 1800 in the embodiment shown in FIG. 24.
  • the third network device is configured to determine a forwarding path of a message, the forwarding path includes a plurality of network devices; the segment list corresponding to the forwarding path is generated, and the segment list includes sequentially arranged
  • the plurality of identifiers each of the plurality of identifiers respectively corresponds to a network device in the plurality of network devices or a link in the forwarding path, and the segment list includes a length of 128 bits
  • the first element includes at least two adjacent identifiers in the plurality of identifiers.
  • the second network device is configured to receive a first message; obtain a segment list, the segment list corresponding to a forwarding path of the first message, the forwarding path includes a plurality of network devices, and the segment list includes A plurality of identifiers arranged in sequence, each of the plurality of identifiers respectively corresponds to a network device of the plurality of network devices or a link in the forwarding path, and the segment list includes a length of 128
  • the first element of the bit the first element includes at least two adjacent identifiers among the plurality of identifiers; adding the segment list to the first message to generate a second message, the first element
  • the second message includes a first pointer, the value of the first pointer is used to indicate the position of the first identifier in the first element, and the first identifier is one of the at least two identifiers; sending the The second message.
  • obtaining the segment list by the second network device means that the second network device receives the segment list sent by the third network device .
  • obtaining the segment list by the second network device means that the second network device generates the segment list.
  • the first network device is configured to receive the second message, the first message header of the second message includes the segment list, and the second message includes the first pointer;
  • the value of a pointer determines the position of the first identifier in the first element; at least one identifier starting with the first identifier is copied to the second header of the second message, To generate a third message; the sending unit is used to send the third message.
  • the embodiment of the present invention also provides a non-transitory storage medium for storing the software instructions used in the foregoing embodiment, which includes a program for executing the method shown in the foregoing embodiment, when it is on a computer or network device When executed, the computer or network device shown is caused to execute the method in the foregoing method embodiment.
  • the embodiment of the present invention also provides a computer program product including computer program instructions, which when the computer program product runs on a computer, causes a network node to execute the method in the foregoing method embodiment.
  • the "first" of the first message, the first network device, the first identifier, the first pointer, and the quantity identifier mentioned in the embodiment of the present invention is only used as a name identifier, and does not represent the first in order. This rule also applies to "second", “third” and “fourth”. However, the "first” in the first identifier mentioned in the embodiment of the present invention represents the first in order. This rule also applies to the "Nth”.
  • a and/or B is considered to include A alone, B alone, and A+B.
  • any of the device embodiments described above are only illustrative, and the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physically separate.
  • the physical unit can be located in one place or distributed across multiple network units. Some or all of the modules can be selected according to actual needs to achieve the objectives of the solutions of the embodiments.
  • the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement it without creative work.
  • the steps of the method or algorithm described in the disclosure of the embodiment of the present invention may be implemented in a hardware manner, or may be implemented in a manner in which a processor executes software instructions.
  • Software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable read-only memory (erasable programmable ROM, EPROM), electrically erasable programmable read-only memory (electrically erasable programmable read-only memory (EPROM, EEPROM), hard disk, mobile hard disk, optical disk, or any other form of storage medium known in the art.
  • the storage medium is coupled to the processor, so that the processor can read information from the storage medium.
  • the storage medium may also be an integral part of the processor.

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Abstract

公开了一种转发报文的方法。该方法包括：接收报文，报文的第一报文头中包括用于转发报文的段列表，段列表包括依次排列的多个标识，多个标识中的每个标识分别对应于一个网络设备或一个链路，列表包括长度为128比特的第一元素，第一元素包括多个标识中的相邻的至少两个标识，第一报文包括第一指针；根据第一指针的值确定第一标识在第一元素中的位置，第一标识为至少两个标识中的一个；将以第一标识为起始的至少一个标识拷贝至第一报文的第二报文头中，以生成第二报文；并发送第二报文。通过该方法，能够减少段列表的长度，提高报文传输的效率。

Description

一种在SR网络中转发报文的方法、设备和系统
本申请要求于2019年8月31日提交中国国家知识产权局、申请号201910819877.6、申请名称为“一种在SR网络中转发报文的方法、设备和系统”的中国专利申请、以及于2019年12月19日提交中国国家知识产权局、申请号201911317222.5、申请名称为“一种在SR网络中转发报文的方法、设备和系统”的中国专利申请的优先权，它们的全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信领域，尤其涉及一种在段路由(segment routing,SR)网络中转发报文的方法、网络设备和系统。
背景技术
SR是一种基于源路由理念设计的、在网络上转发数据包的协议，支持在源节点显式指定数据包转发路径。当SR部署在第六版本的互联网协议6(Internet Protocol Version 6，IPv6)数据平面上时，称为IPv6segment routing(SRv6)，当SR部署在多协议标签交换(Multiple Protocol Label Switch，MPLS)数据平面上时，称为SR-MPLS。其中，SRv6在IPv6的基础上扩展了段路由头(segment routing header,SRH)。
SRH包括段列表(segment list)，segment list包括依次排列的多个段标识(segment identification,SID)，每个SID对应报文转发路径中的一个节点或链路。SRH被封装在报文中，通过其中的segment list承载SR网络对该报文的转发和处理过程。其中，每个SID是一个128比特(bit)的IPv6地址。由于每个SID在报文中占用128bit，因此在段列表中每增加一个SID，SRH的长度就会增加128bit，相应的，报文的长度也会增加128bit。一方面，报文长度增加将导致转发过程中占用大量的网络资源，如：带宽。举例来说，当报文转发路径中包括100个节点时，SRH包括100个SID，段列表长度高达1600字节，段列表长度过长，降低SR网络中报文传输的效率。
发明内容
本申请提供了一种转发报文的方法、设备和系统，用于解决段列表长度过长导致SR网络中报文传输效率降低的技术问题。
第一方面，提供了一种转发报文的方法。所述方法包括：接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针；根据所述第一指针的值确定所述第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一 个；将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文；发送所述第二报文。
该方法可以由报文转发路径上的中间节点执行。其中，所述段列表可以是SRv6报文的SRH中的段列表。所述段列表中长度为128比特的元素中能够存放至少两个对应于网络设备的标识，不需要每个标识都占用128比特，从而减少段列表的长度，减少报文的长度，提升报文传输效率。每个128比特的元素中存放的标识的数量可以根据网络的实际情况调整。当一个128比特元素中包含多个标识时，这些标识可以理解成压缩段标识(micro segment ID,USID)。通过在报文头中包括的第一指针，能够准确、快速的获得压缩段标识在元素内部的位置。
在一种可能的实现方式中，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于一个网络设备或一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述多个段标识的的每个段标识的第一部分为所述前缀部分，所述多个段标识的前缀部分相同，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。USID可以通过省略SID中的部分内容而获得。由于在一个域(domain)内，所有网络设备的SID的BLOCK部分是相同的，因此，可以通过省略SID的BLOCK以获得USID，将USID放入段列表中，从而减少段列表的长度。
在一种可能的实现方式中，所述第二报文头包括目的地址(destiantion address,DA)字段，所述目的地址字段包括第一部分和第二部分；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中，包括：将以所述第一标识为起始的至少一个标识拷贝至所述目的地址字段的第二部分中。所述第一标识为待添加至DA字段中的标识，也可以称为待添加的标识，且所述第一标识可以为USID，当段列表的元素中包括多个标识时，网络设备根据第一指针在多个标识中确定第一标识，将以第一标识为起始的至少一个标识拷贝至DA字段中，并且SID的前缀部分也被直接放入DA字段中，从而SID的前缀部分和以第一标识为起始的至少一个标识组合起来，指导报文转发。
在一种可能的实现方式中，所述多个标识的长度相同；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之前，所述方法还包括：根据所述多个标识的长度和所述前缀部分的长度确定所述至少一个标识的数量。在DA字段中，一部分被前缀部分占据，另一部分被拷贝至DA字段的至少一个USID占据，网络设备可以根据USID的长度和前缀部分的长度确定能够拷贝至DA字段的至少一个USID的数量。
在一种可能的实现方式中，所述段列表不包括所述前缀部分。由于头节点在报文中添加SRH时，也将当前待处理的USID以及该USID对应的BLOCK部分存放在DA字段中，其中，在DA字段中与BLOCK部分相邻的USID可以称为active USID。因此，对于active USID，以及与active USID对应相同的前缀部分的其他USID来说，段列表中可以不再存放这些USID对应的前缀部分，而只存放这些USID本身。从而，减少段列表的长度。
在一种可能的实现方式中，所述第一报文包括目的地址字段，所述目的地址字 段包括第二标识，所述第二标识是所述多个标识中的一个；所述根据所述第一指针的值确定所述第一标识在所述第一元素中的位置之前，所述方法还包括：根据所述第二标识中的切换标志，确定所述段列表中包括与所述第二标识的类型不同的标识；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中，包括：将所述至少一个标识拷贝至所述第二报文头中以形成转发标识栈，所述至少一个标识与所述第二标识的类型不同。段列表中还可以包括其他类型的标识，如MPLS标签或互联网协议版本4(Internet Protocol，IPv4)地址，网络设备在报文头中建立转发标识栈，将这些其他类型的标识拷贝至转发标识栈中。从而，该方法能够兼容更多的网络场景，并且通过段列表对整个转发路径进行编程，提高转发效率。
在一种可能的实现方式中，所述第一报文包括数量标志；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之前，所述方法还包括：根据所述数量标志的值确定所述至少一个标识的数量。其中，至少一个标识是其他类型的标识，如MPLS标签或IPv4地址，在将这些其他类型的标识拷贝至转发标识栈中之前，网络设备可以先根据数量标志确定这些其他类型的标识的数量，从而将相应数量的其他类型的标识拷贝至转发标识栈中。
在一种可能的实现方式中，所述根据所述第一指针的值确定所述第一标识在所述第一元素中的位置，包括：确定所述目的地址字段中多余标识的数量，所述多余标识的类型与所述第二标识不同；根据所述多余标识的数量校正所述第一指针的值；根据校正后的所述第一指针的值确定所述第一标识在所述第一元素中位置。所述第一标识是至少一个其他类型的标识中的第一个标识，所述多余标识是已经添加至DA字段中的其他类型的标识。网络设备根据已经添加至DA字段中的其他类型的标识的数量，对第一指针的值进行校正，根据校正后的所述第一指针的值确定段列表中待添加至DA字段的至少一个标识的起始位置。
在一种可能的实现方式中，所述将以所述第一标识为起始的至少一个标识拷贝至所述转发标识栈中，包括：将以所述至少一个标识中的最后一个标识的后一个标识添加在所述第一报文的目的地址字段中。网络设备还将段列表中其他类型的标识之后的压缩段标识拷贝至DA字段中，以便在所述转发标识栈被弹出以后，继续根据所述DA字段转发报文。
在一种可能的实现方式中，所述至少一个标识为MPLS标签或IPv4地址。所述其他类型的标识可以是MPLS标签或IPv4地址。
在一种可能的实现方式中，所述第一指针包括在所述第一报文头中。第一指针可以在SRH的特定字段中，也可以在段列表中。
在一种可能的实现方式中，所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之后，所述方法还包括：修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第二标识在所述第一元素中的位置，所述第二标识不属于所述至少一个标识。网络设备修改所述第一指针的值，以使得所述第一指针的值始终指向待添加的标识，从而转发路径上的后续网络设备能够继续根据第一指针的值确定待添加的标识。
在一种可能的实现方式中，所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之后，所述方法还包括：修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第二标识在第二元素中的位置，所述第二标识不属于所述至少一个标识，所述第二元素与所述第一元素不同。当前元素中的标识处理完毕以后，网络设备可以将所述第一指针指向下一个元素中的标识，例如，将所述第一指针的值归0，从而指向下一个元素的起始位置。
第二方面，提供了一种转发报文的方法。所述方法包括：接收第一报文；获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；发送所述第二报文。
该方法可以由报文转发路径上的入口节点执行。其中，所述段列表可以是SRv6报文的SRH中的段列表。所述段列表中长度为128比特的元素中能够存放至少两个对应于网络设备的标识，不需要每个标识都占用128比特，从而减少段列表的长度，减少报文的长度，提升报文传输效率。每个128比特的元素中存放的标识的数量可以根据网络的实际情况调整。当一个128比特元素中包含多个标识时，报文转发路径上的入口节点在报文头中添加第一指针，用于指示不同标识在元素内部的位置，从而使得报文转发路径上的中间节点能够准确、快速的获得标识在元素内部的位置。
在一种可能的实现方式中，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个段标识的前缀部分相同，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。USID可以通过省略SID中的部分内容而获得。由于在一个domain内，所有网络设备的SID的BLOCK部分是相同的，因此，可以通过省略SID的BLOCK部分以获得USID，将USID放入段列表中，从而减少段列表的长度。
在一种可能的实现方式中，所述第一报文的报文头包括目的地址字段，所述目的地址字段包括第一部分和第二部分；所述在所述第一报文中添加所述段列表以生成所述第二报文，包括：在所述目的地址字段的第一部分中添加所述前缀部分；在所述目的地址字段的第二部分中添加所述多个标识中的一个或多个标识。由于段列表中的USID中省略了SID的前缀部分，因而转发路径上的入口节点将前缀部分直接添加至DA字段中，并且还将段列表中的第一个标识添加至DA字段中，从而SID的前缀部分和所述第一标识组合起来，指导报文转发。
在一种可能的实现方式中，所述段列表不包括所述前缀部分。SID的前缀部分存放在DA字段中，段列表中只存放USID，而不再存放SID的前缀部分。从而，减少段列表的长度。
在一种可能的实现方式中，所述多个标识中的至少一个标识为MPLS标签或IPv4地址。
在一种可能的实现方式中，所述第二报文包括数量标志，所述数量标志的值用于指示所述至少一个标识的数量。段列表中还可以包括其他类型的标识，此时，转发路径的入口节点在所述报文中添加数量标志，用于指示其他类型的标识的数量。
在一种可能的实现方式中，所述第一指针位于所述第二报文的报文头中。第一指针可以在SRH的特定字段中，也可以在段列表中。
在一种可能的实现方式中，所述第二报文还包括第二指针，所述第二指针的值用于指示所述第一元素在所述段列表中的位置。所述第二指针可以是段剩余(Segment Left,SL)指针。
在一种可能的实现方式中，所述获得段列表包括：接收所述段列表。所述段列表可以是转发路径的入口节点从网络中的控制器接收到的。
在一种可能的实现方式中，所述获得段列表包括：确定所述第一报文的所述转发路径，生成对应于所述转发路径的所述段列表。所述段列表可以是转发路径的入口节点生成的。
第三方面，提供了一种生成用于转发报文的段列表的方法，其特征在于，所述方法包括：确定报文的转发路径，所述转发路径包括多个网络设备；
生成对应于所述转发路径的所述段列表，所述段列表包括依次排列的所述多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识。
该方法可以由生成段列表的网络设备执行，该生成段列表的网络设备可以是网络中的控制器，也可以是网络中的报文转发路径的入口节点。其中，所述段列表可以是SRv6报文的SRH中的段列表。网络设备在段列表中长度为128比特的元素中存放至少两个对应于网络设备的标识，而不是每128比特仅存放一个标识，从而减少段列表的长度，减少报文的长度，提升报文传输效率。每个128比特的元素中存放的标识的数量可以根据网络的实际情况调整。当一个128比特元素中包含多个标识时，这些标识可以理解成压缩段标识(USID)。
在一种可能的实现方式中，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个标识的每个标识分别包括所述每个标识所映射到的段标识的第二部分。USID可以通过省略SID中的部分内容而获得。由于在一个domain内，所有网络设备的SID的BLOCK部分是相同的，因此，可以通过省略SID的BLOCK部分以获得USID，将USID放入段列表中，从而减少段列表的长度。
在一种可能的实现方式中，所述多个段标识中的段标识还包括第三部分，所述第三部分为填充部分，所述多个段标识的填充部分相同，所述多个标识中的标识不包括所述填充部分。USID中的功能字段可以是压缩的功能字段，压缩的功能字段的 长度小于非压缩的功能字段的长度。从而，USID的长度小于SID的长度，将USID放入段列表中，从而减少段列表的长度。
在一种可能的实现方式中，所述多个段标识包括第一段标识，所述段列表不包括所述第一段标识的前缀部分。所述多个段标识包括第一段标识，所述段列表不包括所述第一段标识的前缀部分。段列表中只存放USID，而不再存放SID的前缀部分。从而，减少段列表的长度。
在一种可能的实现方式中，所述多个段标识还包括第二段标识，所述第一段标识的前缀部分和所述第二段标识的前缀部分不同，所述段列表包括所述第二段标识的前缀部分。当转发路径上的多个网络设备属于不同的网络域时，这些网络设备的SID的前缀部分至少有两种，此时，第一种前缀部分不存放在段列表中，第二种前缀部分存放在段列表中。第一种前缀部分由转发路径的入口节点直接放入DA字段中。
在一种可能的实现方式中，所述多个标识中的至少一个标识为段标识、MPLS标签或IPv4地址。
在一种可能的实现方式中，所述段列表还包括数量标志，所述数量标志的值用于指示所述至少一个其他标识的数量。
在一种可能的实现方式中，所述生成对应于所述转发路径的所述段列表之后，所述方法还包括：向所述转发路径的入口设备发送所述段列表；或者，将所述段列表封装至报文中，并发送所述报文。当生成段列表的网络设备为网络中的控制器时，控制器生成段列表并向转发路径的入口节点发送，以便入口节点将段列表封装至报文中，指导报文转发。当生成段列表的网络设备为报文转发路径的入口节点时，该入口节点将所述段列表封装至报文中，指导报文转发。
第四方面，提供了一种网络设备，执行第一方面或第一方面的任意一种可能的实现方式，或者第十五方面或第十五方面的任意一种可能的实现方式中的方法。具体地，该网络设备包括用于执行第一方面或第一方面的任意一种可能的实现方式，或者第十五方面或第十五方面的任意一种可能的实现方式中的方法的单元。
第五方面，提供了一种网络设备，执行第二方面或第二方面的任意一种可能的实现方式，或者第十六方面或第十六方面的任意一种可能的实现方式中的方法。具体地，该网络设备包括用于执行第二方面或第二方面的任意一种可能的实现方式，或者第十六方面或第十六方面的任意一种可能的实现方式中的方法的单元。
第六方面，提供了一种网络设备，执行第三方面或第三方面的任意一种可能的实现方式中的方法。具体地，该网络设备包括用于执行第三方面或第三方面的任意一种可能的实现方式中的方法的单元。
第七方面，提供了一种网络设备，该网络设备包括：处理器、通信接口和存储器。通信接口可以是收发器。存储器可以用于存储程序代码，处理器用于调用存储器中的程序代码执行前述第一方面或第一方面的任意一种可能的实现方式，或者第十五方面或第十五方面的任意一种可能的实现方式，此处不再赘述。
第八方面，提供了一种网络设备，该网络设备包括：处理器、通信接口和存储器。通信接口可以是收发器。存储器可以用于存储程序代码，处理器用于调用存储器中的程序代码执行前述第二方面或第二方面的任意一种可能的实现方式，或者第 十六方面或第十六方面的任意一种可能的实现方式，此处不再赘述。
第九方面，提供了一种网络设备，该网络设备包括：处理器、通信接口和存储器。通信接口可以是收发器。存储器可以用于存储程序代码，处理器用于调用存储器中的程序代码执行前述第三方面或第三方面的任意一种可能的实现方式，此处不再赘述。
第十方面，提供了一种网络系统，该网络系统包括前述第四、五或六方面提供的网络设备，或者该网络系统包括前述第七、八或九方面提供的网络设备。
第十一方面，提供了一种计算机可读存储介质，所述计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机执行上述第一方面、第二方面、第三方面、第十五方面、第十六方面、第一方面的任意一种可能的实现方式、第二方面的任意一种可能的实现方式、第三方面的任意一种可能的实现方式、第十五方面的任意一种可能的实现方式或者第十六方面的任意一种可能的实现方式所述的方法。
第十二方面，提供了一种包括计算机程序指令的计算机程序产品，当该计算机程序产品在网络设备上运行时，使得网络设备执行第一方面、第二方面、第三方面、、第十五方面、第十六方面、第一方面的任意一种可能的实现方式、第二方面的任意一种可能的实现方式、第三方面的任意一种可能的实现方式、第十五方面的任意一种可能的实现方式或者第十六方面的任意一种可能的实现方式中提供的方法。
第十三方面，提供了一种芯片，包括存储器和处理器，存储器用于存储计算机程序，处理器用于从存储器中调用并运行该计算机程序，以执行上述第一方面及其第一方面任意可能的实现方式中的方法，或者，处理器执行第二方面或第二方面任意可能的实现方式中的方法，或者，处理器执行第三方面或第三方面任意可能的实现方式中的方法，或者处理器执行第十五方面或第十五方面的任意一种可能的实现方式中的方法，或者处理器执行第十六方面或第十六方面的任意一种可能的实现方式中的方法。
可选地，上述芯片仅包括处理器，处理器用于读取并执行存储器中存储的计算机程序，当计算机程序被执行时，处理器执行第一方面或第一方面任意可能的实现方式中的方法，或者，处理器执行第二方面或第二方面任意可能的实现方式中的方法，或者，处理器执行第三方面或第三方面任意可能的实现方式中的方法，或者处理器执行第十五方面或第十五方面的任意一种可能的实现方式中的方法，或者处理器执行第十六方面或第十六方面的任意一种可能的实现方式中的方法。
第十四方面，提供了一种转发报文的方法。所述方法包括：接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的标识对应于一个网络设备或一个链路，所述段列表包括第一元素和第二元素，所述第一元素和所述第二元素的长度为128比特，所述第一元素包括所述多个标识中的相邻的至少两个标识；所述第一报文的第二报文头中包括目的地址字段，所述目的地址字段中包括第一标识，所述第一标识为所述多个标识中的一个标识；根据所述第一标识的指示向所述目的地址字段中添加所 述第二元素，以生成第二报文；发送所述第二报文。
该方法可以由报文转发路径上的中间节点执行。其中，所述段列表可以是SRv6报文的SRH中的段列表。所述段列表中长度为128比特的元素中能够存放至少两个对应于网络设备的标识，不需要每个标识都占用128比特，从而减少段列表的长度，减少报文的长度，提升报文传输效率。当一个128比特元素中包含多个标识时，这些标识可以理解成压缩段标识(USID)。所述段列表中还可以存放长度为128比特的段标识(SID)，即SID与USID同时存放在段列表中。在被添加至DA字段中时，SID与USID对应不同的添加方式，因而需要在USID与SID之间设置切换标志，网络设备可以从DA字段中获得该切换标志，并根据切换标志的指示采取相应的添加方式，例如，将SID添加至DA字段中时，将段列表中长度为128比特的元素整体添加至DA字段中。从而，确保报文转发。
第十五方面，提供了一种转发报文的方法。所述方法包括：接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针；根据所述第一指针的值确定第一标识在所述段列表中的位置，所述第一标识为所述至少两个标识中的一个；将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文；发送所述第二报文。
该方法可以由报文转发路径上的中间节点执行。其中，所述段列表可以是SRv6报文的SRH中的段列表。所述段列表中长度为128比特的元素中能够存放至少两个对应于网络设备的标识，不需要每个标识都占用128比特，从而减少段列表的长度，减少报文的长度，提升报文传输效率。每个128比特的元素中存放的标识的数量可以根据网络的实际情况调整。当一个128比特元素中包含多个标识时，这些标识可以理解成压缩段标识(micro segment ID,USID)。通过在报文头中包括的第一指针，能够准确、快速的获得压缩段标识在元素内部的位置。
在一种可能的实现方式中，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于一个网络设备或一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述多个段标识的的每个段标识的第一部分为所述前缀部分，所述多个段标识的前缀部分相同，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。USID可以通过省略SID中的部分内容而获得。由于在一个域(domain)内，所有网络设备的SID的BLOCK部分是相同的，因此，可以通过省略SID的BLOCK以获得USID，将USID放入段列表中，从而减少段列表的长度。
在一种可能的实现方式中，所述第二报文头包括目的地址(destiantion address,DA)字段，所述目的地址字段包括第一部分和第二部分；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中，包括：将以所述第一标识为起始的至少一个标识拷贝至所述目的地址字段的第二部分中。所述第一标识为待添加至DA字段中的标识，也可以称为待添加的标识，且所述第一标识可以为 USID，当段列表的元素中包括多个标识时，网络设备根据第一指针在多个标识中确定第一标识，将以第一标识为起始的至少一个标识拷贝至DA字段中，并且SID的前缀部分也被直接放入DA字段中，从而SID的前缀部分和以第一标识为起始的至少一个标识组合起来，指导报文转发。
在一种可能的实现方式中，所述多个标识的长度相同；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之前，所述方法还包括：根据所述多个标识的长度和所述前缀部分的长度确定所述至少一个标识的数量。在DA字段中，一部分被前缀部分占据，另一部分被拷贝至DA字段的至少一个USID占据，网络设备可以根据USID的长度和前缀部分的长度确定能够拷贝至DA字段的至少一个USID的数量。
在一种可能的实现方式中，所述段列表不包括所述前缀部分。由于头节点在报文中添加SRH时，也将当前待处理的USID以及该USID对应的BLOCK部分存放在DA字段中，其中，在DA字段中与BLOCK部分相邻的USID可以称为active USID。因此，对于active USID，以及与active USID对应相同的前缀部分的其他USID来说，段列表中可以不再存放这些USID对应的前缀部分，而只存放这些USID本身。从而，减少段列表的长度。
在一种可能的实现方式中，所述第一报文包括目的地址字段，所述目的地址字段包括第二标识，所述第二标识是所述多个标识中的一个；所述根据所述第一指针的值确定所述第一标识在所述段列表中的位置之前，所述方法还包括：根据所述第二标识中的切换标志，确定所述段列表中包括与所述第二标识的类型不同的标识；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中，包括：将所述至少一个标识拷贝至所述第二报文头中以形成转发标识栈，所述至少一个标识与所述第二标识的类型不同。段列表中还可以包括其他类型的标识，如MPLS标签或互联网协议版本4(Internet Protocol，IPv4)地址，网络设备在报文头中建立转发标识栈，将这些其他类型的标识拷贝至转发标识栈中。从而，该方法能够兼容更多的网络场景，并且通过段列表对整个转发路径进行编程，提高转发效率。
在一种可能的实现方式中，所述第一报文包括数量标志；所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之前，所述方法还包括：根据所述数量标志的值确定所述至少一个标识的数量。其中，至少一个标识是其他类型的标识，如MPLS标签或IPv4地址，在将这些其他类型的标识拷贝至转发标识栈中之前，网络设备可以先根据数量标志确定这些其他类型的标识的数量，从而将相应数量的其他类型的标识拷贝至转发标识栈中。
在一种可能的实现方式中，所述将以所述第一标识为起始的至少一个标识拷贝至所述转发标识栈中，包括：将以所述至少一个标识中的最后一个标识的后一个标识添加在所述第一报文的目的地址字段中。网络设备还将段列表中其他类型的标识之后的压缩段标识拷贝至DA字段中，以便在所述转发标识栈被弹出以后，继续根据所述DA字段转发报文。
在一种可能的实现方式中，所述至少一个标识为MPLS标签或IPv4地址。所述 其他类型的标识可以是MPLS标签或IPv4地址。
在一种可能的实现方式中，所述第一指针包括在所述第一报文头中。第一指针可以在SRH的特定字段中，也可以在段列表中。
在一种可能的实现方式中，所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之后，所述方法还包括：修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第二标识在所述段列表中的位置，所述第二标识不属于所述至少一个标识。网络设备修改所述第一指针的值，以使得所述第一指针的值始终指向待添加的标识，从而转发路径上的后续网络设备能够继续根据第一指针的值确定待添加的标识。
第十六方面，提供了一种转发报文的方法。所述方法包括：接收第一报文；获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述段列表中的位置，所述第一标识为所述至少两个标识中的一个；发送所述第二报文。
该方法可以由报文转发路径上的入口节点执行。其中，所述段列表可以是SRv6报文的SRH中的段列表。所述段列表中长度为128比特的元素中能够存放至少两个对应于网络设备的标识，不需要每个标识都占用128比特，从而减少段列表的长度，减少报文的长度，提升报文传输效率。每个128比特的元素中存放的标识的数量可以根据网络的实际情况调整。当一个128比特元素中包含多个标识时，报文转发路径上的入口节点在报文头中添加第一指针，用于指示不同标识在段列表中的位置，从而使得报文转发路径上的中间节点能够准确、快速的获得标识在段列表中的位置。
在一种可能的实现方式中，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个段标识的前缀部分相同，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。USID可以通过省略SID中的部分内容而获得。由于在一个domain内，所有网络设备的SID的BLOCK部分是相同的，因此，可以通过省略SID的BLOCK部分以获得USID，将USID放入段列表中，从而减少段列表的长度。
在一种可能的实现方式中，所述第一报文的报文头包括目的地址字段，所述目的地址字段包括第一部分和第二部分；所述在所述第一报文中添加所述段列表以生成所述第二报文，包括：在所述目的地址字段的第一部分中添加所述前缀部分；在所述目的地址字段的第二部分中添加所述多个标识中的一个或多个标识。由于段列表中的USID中省略了SID的前缀部分，因而转发路径上的入口节点将前缀部分直接添加至DA字段中，并且还将段列表中的第一个标识添加至DA字段中，从而SID的前缀部分和所述第一标识组合起来，指导报文转发。
在一种可能的实现方式中，所述段列表不包括所述前缀部分。SID的前缀部分存放在DA字段中，段列表中只存放USID，而不再存放SID的前缀部分。从而，减少段列表的长度。
在一种可能的实现方式中，所述多个标识中的至少一个标识为MPLS标签或IPv4地址。
在一种可能的实现方式中，所述第二报文包括数量标志，所述数量标志的值用于指示所述至少一个标识的数量。段列表中还可以包括其他类型的标识，此时，转发路径的入口节点在所述报文中添加数量标志，用于指示其他类型的标识的数量。
在一种可能的实现方式中，所述第一指针位于所述第二报文的报文头中。第一指针可以在SRH的特定字段中，也可以在段列表中。
在一种可能的实现方式中，所述获得段列表包括：接收所述段列表。所述段列表可以是转发路径的入口节点从网络中的控制器接收到的。
在一种可能的实现方式中，所述获得段列表包括：确定所述第一报文的所述转发路径，生成对应于所述转发路径的所述段列表。所述段列表可以是转发路径的入口节点生成的。
附图说明
为了更清楚地说明本申请的技术方案，下面将对实施例中使用的附图作简单地介绍。显而易见地，下面附图只是本申请的一些实施例的附图，对于本领域普通技术人员来说，在不付出创造性劳动性的前提下，还可以根据这些附图获得同样能实现本申请的其他技术方案和附图。
图1为本申请实施例提供的一种应用场景示意图；
图2为本申请实施例提供的一种SID的格式示意图；
图3为本申请实施例提供的一种报文的结构示意图；
图4为本申请实施例提供的一种段列表的结构示意图；
图5为本申请实施例提供的一种SID的结构示意图；
图6为本申请实施例提供的一种段列表的结构示意图；
图7为本申请实施例提供的一种段列表的结构示意图；
图8为本申请实施例提供的一种段列表的结构示意图；
图9为本申请实施例提供的一种报文的结构示意图；
图10为本申请实施例提供的一种报文的结构示意图；
图11为本申请实施例提供的一种报文的结构示意图；
图12为本申请实施例提供的一种报文的结构示意图；
图13为本申请实施例提供的一种报文的结构示意图；
图14为本申请实施例提供的一种报文的结构示意图；
图15为本申请实施例提供的一种报文的结构示意图；
图16为本申请实施例提供的一种报文的结构示意图；
图17为本申请实施例提供的一种报文的结构示意图；
图18为本申请实施例提供的一种处理报文的方法流程图；
图19为本申请实施例提供的一种处理报文的方法流程图；
图20为本申请实施例提供的一种网络设备的结构示意图；
图21为本申请实施例提供的一种网络设备的结构示意图；
图22为本申请实施例提供的一种网络设备的结构示意图；
图23为本申请实施例提供的一种网络设备的结构示意图；
图24为本申请实施例提供的一种网络设备的结构示意图；
图25为本申请实施例提供的一种网络系统的结构示意图。
具体实施方式
下面结合附图，对本申请的实施例进行描述。
图1示出了本申请实施例的一种可能的应用场景。该应用场景的网络中包括网络设备，具体包括：网络设备S、网络设备1、网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9、网络设备10、网络设备11和网络设备12。这些网络设备可以是交换机、路由器或转发器。其中，网络设备S可以是网络的入口设备。网络设备还可以包括控制器，图1中未示出。控制器可以与网络设备1至10连接。控制器可以生成对应报文的转发路径的段列表，并将段列表发送至网络入口设备。控制器可以向网络设备1至12发送包含网络配置信息的控制报文。本申请实施例中的网络设备也可以称为网络节点，或者节点。
其中，网络设备S为支持SR的网络设备。网络设备1至网络设备12可以是支持SR的网络设备，具体的，所述网络设备可以是支持SRv6的网络设备，或者，所述网络设备也可以是支持MPLS的网络设备。网络设备1至网络设备12也可以是支持IPv4但不支持SR的网络设备。
在SR网络中，对报文的处理过程由多个段组成，每个段为处理报文的指令或指令集合。在SRv6网络中，每个段具有相应的段标识，即SID。段标识包括节点段标识(node SID)和邻接段标识(adjacent SID)两种类型。图2示出了SRv6网络中SID的格式，如图2所示，每个SID可以包括位置(Locator)字段和功能(Function)字段。
SID中的位置字段用于定位到执行段所包括的指令或指令集合的具体网络设备。位置字段包括前缀(BLOCK)部分和序号(Node ID)部分。在一个SRv6网络域(domain)内，网络设备的SID的前缀部分可以是相同的。在一个SRv6网络域(domain)内，每个网络设备的SID的序号部分是不同的，每个序号部分用于唯一确定该域内的一个网络设备。对于一个特定的SID来说，该SID的序号部分所唯一确定的网络设备就是执行该SID所标识的段的网络设备。
SID中的功能字段用于表示段所包括的指令或指令集合的具体内容，也就是SRv6网络中的功能(Function)。SRv6网络中的功能还可能涉及到参数，用SID中的参数(Argument)字段表示(图2中未示出)。当功能不涉及参数时，则SID中可以不包括参数字段。
通常来说，SRv6网络中SID的总长度为128比特。其中位置字段和功能字段分别为特定长度，且这些特定长度是可以通过网络设置进行改变的。例如，位置字段 为48比特，功能字段为80比特，或者位置字段为64比特，功能字段为64比特，或者位置字段为48比特，功能字段为64比特，参数字段为16比特。
多个SID组成段列表。图3示出了SRv6网络中报文的格式。如图3所示，该报文的报文头包括IPv6报文头和SRH，IPv6报文头包括目的地址(destination address,DA)字段，SRH包括段列表，段列表包括依次排列的多个SID。这些SID可以是节点段标识、邻接段标识、或节点段标识和邻接段标识的组合。
段列表可以由报文转发路径上的入口节点封装在报文中，报文转发路径上后续的网络设备可以根据报文中的段列表处理该报文。具体的，报文由转发路径上的入口节点发出，转发路径上的特定网络设备接收报文。该网络设备确定报文的IPv6报文头的DA字段中包括该网络设备的SID，则根据该SID所标识的段所对应的指令集合对报文进行处理。所述处理报文的具体方式例如可以是转发报文。该网络设备还需要更新所述DA字段。在更新DA字段的过程中，需要利用SRH中的段剩余(segments left,SL)指针。如图3所示，段列表中包括依次排列的多个SID，即Segment List[0]至Segment List[n]。所述多个SID分别对应于报文转发路径上的多个网络设备，多个网络设备分别执行多个段所对应的指令集合。SL指针可以依次指向段列表中的多个SID。具体的，在报文的处理过程中，每执行一个段就更新一次SL指针的值，SL指针每次更新后在段列表中指向的位置偏移一个SID的长度，即128比特，随着对段列表中多个SID所表示的多个段的依次执行，不断更新SL指针的值。因此，该SL指针用于指示段列表中剩余待处理的段的数量。或者说，SL指针的每个取值对应于段列表中剩余待处理的段的特定数量，SL指针始终指向当前待处理的SID。并且，按照多个SID所表示的段在报文处理过程中的先后顺序，所述多个SID在段列表中倒序排列，也就是说，最先执行的段的SID排列在段列表中的最下方，后续执行的段的SID依次向上排列，最后执行的段的SID排列在段列表的最上方。参见图3，其中Segment List[n]表示最先执行的段，Segment List[0]表示最后执行的段。例如，SL指针的值为3，则表示段列表中剩余待处理的段的数量为4个，也可以理解为SL指针指向当前待处理的SID，即从下向上数的第4个SID；SL指针的值为0，则表示剩余待处理的段的数量为1个，也可以理解为SL指针指向当前待处理的SID，即从下向上数的最后一个SID，即图3中的Segment List[0]。网络设备根据SL指针确定当前待处理的SID以后，将该SID拷贝至IPv6报文头中的DA字段，用于后续根据DA字段中的内容处理报文。所述处理报文的具体方式例如可以是转发报文。
报文可以通过图1所示的网络进行处理。例如，所述处理方式可以是转发，即报文通过图1所示的网络进行转发。例如，网络设备S向网络设备10发送报文，报文的转发路径依次经过网络设备1、网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9。即网络设备S是该转发路径的头节点。除了头节点网络设备S以外，该转发路径还包括网络设备1至网络设备10，共10个网络设备。如果10个网络设备均为支持SRv6的网络设备，并且每个网络设备处的转发行为分别对应一个段，则表示整个报文转发过程的段列表包括10个SID。每个SID的长度为128比特，段列表的长度为160字节。从而报文中段列表的 存在导致了报文长度的增加，降低网络的传输效率和处理效率。
本申请实施例提供了转发报文的方法以及基于该方法的设备和系统。这些方法、设备和系统基于同一发明构思。通过该方法能够使用长度较小的压缩段标识代替长度为128比特的SID，从而减少段列表的长度，进而减少报文长度，提高网络的传输效率和处理效率。
本发明实施例提供了一种转发报文的方法。该方法涉及报文的转发路径上的各个节点。结合图1所示的应用场景，网络设备S向网络设备10发送报文，报文的转发路径依次经过网络设备1、网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9。该方法的步骤包括：
网络设备S接收报文。网络设备S是网络中的网络入口设备，并且是所述报文的转发路径的入口节点。网络设备S接收报文，该报文可以是主机(图1中未示出)生成的报文，主机可以是个人计算机、手机或平板电脑等终端设备。
作为报文的转发路径的入口节点，网络设备S需要确定接收到的报文的转发路径。可选的，网络设备S可以根据报文的特征从存储的多个转发路径中查找出用于转发所述报文的转发路径，从而确定所述报文的转发路径。所述存储的多个转发路径可以是网络设备S从网络中的控制器接收到的。所述报文的特征可以是报文的五元组中的任意一个元素或多个元素的组合，该五元组包括的元素为：报文的源IP地址、源端口、目的IP地址、目的端口和协议号。可选的，网络设备S也可以根据所述报文携带的信息以及网络拓扑信息计算出用于转发报文的转发路径。所述转发路径包括多个网络设备。结合图1所示的应用场景，网络设备S向网络设备10发送报文，报文的转发路径依次经过网络设备1、网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9。
网络设备S获得段列表。所述段列表可以是SRv6报文的SRH中的段列表。如图4所示，此时的段列表对应于报文的转发路径，所述转发路径包括网络设备1至网络设备10，所述段列表包括依次排列的多个SID，所述多个SID中的每个SID对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，每个SID的长度为128比特。
该段列表可以是网络设备S从控制器接收并存储在设备内部的，具体的，网络设备S从存储的多个转发路径中查找出用于转发所述报文的转发路径，并且查找出对应于该转发路径的段列表。该段列表也可以是网络设备S生成的，具体的，网络设备S根据所述报文携带的信息计算出用于转发报文的转发路径，并且生成对应于该转发路径的段列表。
在SRv6网络中，报文的转发路径也可以用多个段来表示。每个段由特定的网络设备执行，并且每个段具有相应的SID。从而，对于一个段来说，这个段的SID与执行这个段的网络设备之间存在对应关系，即该SID对应于一个网络设备，或者可以说该SID是一个网络设备的SID。
结合图1所示的应用场景进行举例说明，网络设备1的段标识可以是A:1:01:11::，该段标识的长度为128比特，“::”表示全0字节。其中，A:1:01为位置字段，长度为48比特，A:1/48为BLOCK部分，长度为32比特，“/48”表示48位的掩 码，01为序号部分，长度为16比特，即位置字段长度为48比特。11::为功能字段，长度为80比特。类似地，网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9或网络设备10也可以是相同domain内的网络设备，此时，这些网络设备的段标识可以分别是A:1:02:22::,A:1:03:33::,A:1:04:44::,A:1:05:55::,A:1:06:66::,A:1:07:77::,A:1:08:88::,A:1:09:99::,A:1:0a:aa::。
为了减少每个SID的长度，可以省略SID的某个部分或某些部分，以形成压缩段标识(micro segment ID,USID)，将这些USID代替SID放入段列表中，可以减少段列表的长度。
由于在一个domain内，所有网络设备的SID的BLOCK部分可以是相同的，因此，在段列表中，为了减少每个SID的长度，可以省略SID的BLOCK部分，以形成USID。也就是说，将网络设备的SID划分为两部分，第一部分为BLOCK部分，第二部分为SID中除BLOCK部分以外的其余部分，在放入段列表时，将相同的BLOCK部分省略。例如，图1中网络设备1的SID是A:1:01:11::，其中A:1/48为BLOCK部分，01为序号部分，长度为16比特。省略SID的BLOCK部分，剩余部分为01:11::，长度为96比特。类似地，网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9或网络设备10的SID的位置字段的BLOCK部分都可以被省略，剩余部分分别为02:22::,03:33::,04:44::,05:55::,06:66::,07:77::,08:88::,09:99::,0a:aa::。这些剩余部分的长度均小于SID的长度。
可选地，在段列表中，为了减少SID的长度，还可以将SID的功能字段设置为压缩格式，压缩格式的功能字段小于非压缩格式的功能字段。在SID规划时，将所有功能字段分成压缩的功能字段和非压缩的功能字段两部分。图5示出了包括压缩的功能字段的SID，和包括非压缩的功能字段的SID。其中，压缩的功能字段用于表示常用的功能，非压缩的功能字段用于表示不常用的功能。压缩的功能字段的长度小于非压缩的功能字段的长度，例如压缩的功能字段的长度为16比特，非压缩的功能字段的长度为80比特。如图5所示，当SID采用压缩的功能字段时，压缩的功能字段之后为填充部分，填充部分为相同的特定内容，以使得整个SID的长度仍为128比特。例如，该填充部分可以为全0。因此，为了减少SID的长度，当SID中的功能字段为压缩的功能字段时，可以省略压缩的功能字段后的填充部分，以形成USID。例如，图1中网络设备1的SID可以是A:1:01:11::，其中11为功能字段，且为压缩的功能字段，长度为16比特，即填充部分长度为64比特。省略SID的压缩的功能字段后的填充部分，剩余部分为A:1:01:11，长度为64比特。类似地，网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9或网络设备10的SID的压缩的功能字段后的填充部分都可以被省略，剩余部分分别为A:1:02:22,A:1:03:33,A:1:04:44,A:1:05:55,A:1:06:66,A:1:07:77,A:1:08:88,A:1:09:99,A:1:0a:aa。这些剩余部分的长度均小于SID的长度。
可选的，压缩的功能字段的第一个比特和非压缩的功能字段的第一个比特可以被设置为不同值。从而，对于获得的SID，网络设备可以通过功能字段的第一个比特判断该SID的功能字段是压缩的功能字段或者是非压缩的功能字段。例如，压缩的功能字段的第一个比特为0，非压缩的功能字段的第一个比特为1，或者，压缩的功能 字段的第一个比特为1，非压缩的功能字段的第一个比特为0。
优选的，如果同时省略SID的位置字段的BLOCK部分和SID的压缩的功能字段后的填充部分，就可以进一步减少剩余部分的长度，此时USID包括SID的位置字段的序号部分和压缩的功能字段。例如，图1中网络设备1的SID的BLOCK部分和压缩的功能字段后的填充部分可以同时被省略，剩余部分为01:11，长度为32比特。类似地，网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9或网络设备10的SID的位置字段的BLOCK部分和压缩的功能字段后的填充部分都可以被省略，剩余部分分别为02:22,03:33,04:44,05:55,06:66,07:77,08:88,09:99,0a:aa。这些剩余部分的长度均小于SID的长度。
由此可见，USID的长度小于128比特。可选的，USID的长度是可变的。当USID包括SID的位置字段的序号部分和压缩的功能字段时，USID的长度由SID的位置字段的序号部分的长度和压缩的功能字段的长度之和决定。例如，USID的长度可以是16比特，32比特或64比特，等等。USID与SID之间存在一一映射关系，USID与SID表示的段之间也存在一一映射关系，即每个SID都可以获得唯一的一个USID，该SID与该USID之间为一一映射关系。从而，对于一个段来说，这个段的USID与这个段的SID之间存在对应关系，这个段的USID与执行这个段的网络设备之间存在对应关系，即该USID对应于一个网络设备，或者可以说该USID是一个网络设备的USID。
可选的，所有SID的压缩的功能字段的长度相同，所有USID的长度相同。
多个SID按照对应的网络设备在转发路径上的顺序依次排列，就构成段列表。而将段列表中的SID替换为对应的USID，可以减少段列表的长度，进而减少报文的长度，提高网络效率。
在本申请实施例中，将段列表中的空间划分为多个元素，SL指针每次更新后指向不同的元素。例如，可以将每个SID占据的空间划分为一个元素，即每个元素的长度为128比特，SL指针每次更新后在段列表中指向的位置仍然偏移128比特。按照SL指针偏移的先后顺序，可以为段列表中的多个元素进行排序，SL指针最初指向的元素可以被称为第一个元素，其他元素依次类推。由于USID的长度小于128比特，例如USID的长度可以是32比特，因而，网络设备S在段列表的长度为128比特的元素中存放多个USID，例如，至少两个USID，从而达到减少段列表长度的目的。可选的，所述SID的位置字段的BLOCK部分可以包括在段列表中，该BLOCK部分可以包括在段列表中第一个元素中。可选的，所述SID的位置字段的BLOCK部分可以不包括在段列表中。图6示出了段列表的结构，例如，当USID的长度为32比特时，段列表中每个元素存放4个USID。例如，第一个元素中存放USID1,USID2,USID3和USID4，第二个元素中存放USID5,USID6,USID7和USID8。
从而，网络设备S获得段列表。所述段列表对应于第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的标识对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的元素，所述元素包括所述多个标识中的相邻的至少两个标识。
在本申请实施例中，段列表中的多个USID按照所对应的网络设备在转发路径上的顺序依次排列。但对多个USID在元素内部的排列方式不做限定。多个USID在元素内部可以顺序排列，也可以倒序排列。如图6所示，第一个元素中存放的4个USID的排列顺序从上至下可以是USID1,USID2,USID3和USID4，这4个USID的排列顺序从上至下也可以是USID4,USID3,USID2和USID1。
可选的，生成段列表的网络设备可以选择是否生成包括USID的段列表。网络设备可以发布不同长度的掩码，分别对应于压缩的功能字段和非压缩的功能字段。例如，压缩段标识的掩码的长度为SID中位置字段的长度与压缩的功能字段的长度之和，非压缩段标识的掩码的长度为SID中位置字段的长度与非压缩的功能字段的长度之和。并且，压缩段标识的掩码的长度小于非压缩段标识的掩码的长度。结合图1所示的应用场景，对应于网络设备1的压缩的掩码长度为64比特，对应于网络设备1的非压缩的掩码长度为128比特。从而，生成段列表的网络设备获得其他网络设备发布的上述不同长度的掩码。当生成段列表的网络设备生成包括USID的段列表时，将该包括USID的段列表与压缩段标识的掩码绑定。当生成段列表的网络设备生成包括SID的段列表时，将该包括SID的段列表与非压缩的掩码绑定。从而，段列表封装在报文中以后，转发报文的网络设备能够利用不同长度的掩码从段列表中获得SID或USID。
可选的，段列表中可以同时包括USID和其他类型的标识。所述其他类型的标识可以是SID，也就是说，采取USID的段列表中仍然可以夹杂有SID。在报文的转发路径所经过的网络设备中，某些网络设备可能不具备处理USID的能力，此时，段列表中仍然可以存放对应这些网络设备的长度为128比特的SID。从而，提高网络兼容性。如图6所示，当网络设备9不具备处理USID的能力时，段列表中存放对应于网络设备9的SID9，即长度为128比特的A:1:09:99::。
可选的，生成段列表的网络设备可以根据其他网络设备是否具备处理USID的能力，从而决定在段列表中放入这些网络设备的USID或SID。其中，生成段列表的网络设备可以是网络中的控制器，也可以是报文转发路径的入口节点，例如，图1所示的网络设备S。例如，网络设备S获得对应于网络设备9的压缩能力标志，该压缩能力标志用于指示网络设备9是否具备处理USID的能力。当压缩能力标志指示网络设备9具备处理USID的能力时，网络设备S在生成的段列表中存放对应于网络设备9的USID，当压缩能力标志指示网络设备9不具备处理USID的能力时，网络设备S在生成的段列表中存放对应于网络设备9的SID。
可选的，当段列表中存放有对应于某个网络设备的长度为128比特的SID时，在段列表中该段标识的前一个USID中包括提示标志，该提示标志用于指示当前USID的后一个标识为长度为128比特的SID。可选地，该提示标志可以包括在USID的压缩的功能字段部分。例如，可以为每个USID设置两个相关联的压缩的功能字段，当USID中包括提示标志时，采用其中的一个压缩的功能字段，当USID中不包括提示标志时，采用另一个压缩的功能字段。如图6所示，可以为USID8设置两个相关联的压缩的功能字段，分别为87和88，当USID8中包括提示标志时，采用87，当USID8中不包括提示标志时，采用88。由于图6所示的段列表中存放对应于网络设备9的长 度为128比特的SID9，则USID8中应当包括提示标志，即USID8为08:87。
可选的，当段列表中存放有对应于某个网络设备的长度为128比特的SID时，可以在连续的多个USID中除最后一个USID以外的其他USID中包括提示标志，即该提示标志用于指示当前USID的后一个标识仍为长度小于128比特的USID。可选地，该提示标志可以包括在USID的压缩的功能字段部分。例如，可以为每个USID设置两个相关联的压缩的功能字段，当USID中包括提示标志时，采用其中的一个压缩的功能字段，当USID中不包括提示标志时，采用另一个压缩的功能字段。如图6所示，可以为USID7设置两个相关联的压缩的功能字段，分别为77和78，当USID7中包括提示标志时，采用77，当USID7中不包括提示标志时，采用78。由于图6所示的段列表中存放对应于网络设备8的长度小于128比特的USID8，则USID7中应当包括提示标志，即USID7为07:77。
可选的，当段列表中同时包括USID和其他类型的标识时，可以每间隔固定长度设置提示标志，该提示标志用于指示下一个固定长度中标识的类型，也即用于指示下一个固定长度中单个标识的长度。例如，所述固定长度可以是128比特。可选的，所述提示标志可以位于所述固定长度中的最后一个标识中，所述提示标志也可以是一个独立的标识，不包括在任何一个对应于网络设备的标识中。所述提示标志的不同取值对应于不同类型的标识。如图6所示，可以每间隔128比特设置提示标志，该提示标志位于128比特中的最后一个标识中，在USID8中该提示标志的值为0时，表示下一个128比特中标识的类型为SID，具体的，下一个128比特中标识为SID9，而在USID4中该提示标志的值为1时，表示下一个128比特中标识的类型为USID，具体的，下一个128比特中标识为USID5,USID6,USID7和USID8。
可选的，当段列表中同时包括USID和其他类型的标识时，也可以每间隔固定长度设置提示标志，该提示标志用于指示下一个固定长度是否仍属于当前标识。从而可以根据该提示标志确定当前标识的边界，进而确定当前标识为长度128比特的SID或者为长度小于128比特的USID。例如，所述固定长度可以是32比特。所述固定长度也可以是8比特、16比特，等等。例如，所述提示标志可以位于一个比特位中。例如，所述提示标志可以位于所述固定长度中的第一个比特位或者最后一个比特位中。如图6所示，可以每间隔32比特设置提示标志，该提示标志位于32比特中的最后一个比特位中，当该比特位的值为1时，表示下一个固定长度仍属于当前标识，而当该比特位的值为0时，表示下一个固定长度不再属于当前标识。对于USID7所属的32比特，其中最后一个比特位的值为0，表示随后的32比特不再属于当前标识，即随后的32比特为USID8。对于SID8所属的32比特，其中最后一个比特位的值为0，表示随后的32比特不再属于当前标识，即随后的32比特为SID9的第一个32比特。而对于SID9的第一个32比特，其中最后一个比特位的值为1，表示随后的32比特仍属于当前标识，即随后的32比特为SID9的第二个32比特。
可选的，当段列表中存放的长度为128比特的SID之后，需要在段列表中该SID的后一个元素的起始位置放入SID的BLOCK部分。如图6所示，段列表中存放对应于网络设备9的长度为128比特的SID9，则段列表中下一元素起始位置存放一个BLOCK，该BLOCK可以是A:1，长度为32比特。在该BLOCK后继续存放对应于网 络设备10的USID10。
可选的，在段列表的元素中，多个USID依次存放，并且在存放完多个USID后，如果在该元素的末尾仍然有多余的比特，则可以对这些多余的比特进行填充。例如，将这些多余的比特填充为全0。
可选的，当报文的转发路径中的多个网络设备属于不同的domain时，也需要在段列表中放入SID的BLOCK部分。在一个domain内，所有网络设备的SID的BLOCK部分是相同的，而在不同的domain之间，网络设备的SID的BLOCK部分不相同。当一个网络设备与转发路径中的上一跳网络设备属于不同的domain时，需要在段列表中放入该网络设备的SID的BLOCK部分。可选的，该BLOCK部分需要放在一个元素的起始部分，即该BLOCK部分放在上一跳网络设备的USID的后一个元素的起始部分，然后，在该BLOCK部分之后，放入该网络设备的USID。图7示出了一种段列表的结构，结合图1所示的应用场景，网络设备9与网络设备8分属不同的域，网络设备8的SID为A:1:8:88::，网络设备9的SID为A2:9:99::，即网络设备8的SID的BLOCK部分为A:1，网络设备9的SID的BLOCK部分为A2，网络设备8的USID8为8:88，网络设备9的USID9为9:99。如图7所示，对应于网络设备的USID9存放在USID8的下一元素中，并且USID9之前存放BLOCK，该BLOCK为A2，长度为32比特。
作为报文的转发路径的入口节点，网络设备S在报文中添加段列表。具体的，网络设备S在报文的SRH中添加段列表。
可选的，所述报文还包括SL指针。结合以上描述，SRH中包括SL指针，该SL指针指向段列表中的某一元素。在报文的转发过程中，转发路径上的中间节点将SL指针所指向的元素中存放的SID添加至SRH外层的IPv6报文头中的目的地址(destination address,DA)字段中。也就是说，SL指针用于指示段列表中当前待处理的元素。
在采用USID时，由于USID的长度小于SID的长度，原来存放一个SID的元素空间可以存放多个USID。因而需要设置新的指针，用于在每个元素内部指示不同的USID的位置。可选地，所述报文包含第一指针，第一指针的值用于指示需要拷贝到报文头中的第一标识在元素中的位置，该新的指针可以称为PI指针。报文中的SL可以成为第二指针，SL指针的值用于指示不同的元素在段列表中的位置，PI指针的值用于指示不同的USID在该元素中的位置。PI指针与SL指针共同构成二维指针。从而，转发路径上的中间节点能够根据PI指针的值确定段列表的元素中当前待添加的标识，例如，当前待添加的USID。
该PI指针的位置可以在报文头中，所述报文头可以是SRH或IPv6报文头。例如，该PI指针可以位于SRH的PI字段中，或者，该PI指针可以位于IPv6报文头的DA字段中。该PI指针也可以位于段列表。例如，该PI指针可以位于段列表中每个元素中的第一个USID中。
可选的，所述PI指针可以与SL指针相邻。两个相邻的指针可以位于SRH的特定字段中，例如但不限于SL字段。例如，PI指针是SRH中SL字段的一部分。具体的，可以将SL字段中的末尾若干比特划分为PI指针，而将SL字段中的其他部分作 为SL指针。例如，可以将SL字段中的最后两个比特划分为PI指针，而将SL字段中的其他部分作为SL指针。即所述PI指针可以是SL字段中的最后两个比特，即最低位比特和次低位比特。此时，SL指针用于指示段列表中当前待处理的元素，PI指针用于指示需要拷贝到报文头中的第一标识在当前待处理的元素中的位置。此时，由于SL指针和PI指针相邻，也可以将SL指针和PI指针组成的整体视为一个新的指针，则SL指针和PI指针分别为该新的指针的一部分。
可选的，所述报文可以仅包括第一指针，该第一指针的值用于指示需要拷贝到报文头中的第一标识在段列表中的位置，该新的第一指针可以称为XL指针。XL指针为一维指针。可选的，该XL指针可以位于SRH中的特定字段中，例如SL字段，即可以将SL字段整体作为XL指针。具体的，该XL指针可以依次指向段列表中的多个标识，所述多个标识可以多种类型的标识，例如SID或USID。在报文的处理过程中，每执行完段列表中的一个标识所表示的内容，则XL指针在段列表中指向的位置偏移该段对应的标识的长度。例如，当偏移的标识为SID时，该长度为128比特，当偏移的标识为USID时，该长度小于128比特。随着对段列表中多个标识所表示的多个段的依次执行，不断XL指针的位置不断偏移。从而，该XL指针用于指示当前待处理的标识在段列表中的位置。
可选的，网络设备S还在报文中IPv6报文头的DA字段中添加SID的BLOCK部分。可选的，网络设备S还在所述DA字段中添加至少一个标识。该至少一个标识可以是多个标识。该多个标识可以是多个USID，也可以是USID和其他类型标识的组合。也就是说，报文中IPv6报文头的DA字段也可以划分为两部分。DA字段的第一部分中放入在段列表中省略的BLOCK部分，DA字段的第二部分中放入至少一个标识。
可选的，网络设备S在所述DA字段中添加的至少一个标识的数量由BLOCK的长度和标识的长度决定。网络设备S在DA字段中除BLOCK以外的部分中，添加尽量多的标识。例如，当该多个标识是多个USID时，多个USID的数量可以是(128-L BLOCK)/L USID的整数部分，其中，L BLOCK是BLOCK的长度，L USID是USID的长度。例如，当BLOCK的长度为32比特，USID的长度为32比特时，3个USID被添加至DA字段。例如，当其他类型的标识与USID的长度相同时，则包括USID和其他类型的标识的组合的多个标识的数量也可以是(128-L BLOCK)/L USID的整数部分。例如，当BLOCK的长度为32比特，USID的长度为32比特，MPLS标签的长度为32比特时，2个USID和1个MPLS标签的组合被添加至DA字段。
结合图9进行举例说明。图9示出了添加有段列表和PI指针的报文的结构，PI指针位于SRH的PI字段中。并且，网络设备S在DA字段中添加SID的BLOCK部分。在DA字段的BLOCK之后，添加3个USID。如图9所示，3个USID为USID1,USID2,USID3。PI指针的值为3，表示段列表的该元素中前3个USID已经添加至DA字段中。根据PI指针的值能够确定该元素中待添加的标识，即第4个USID，USID4。
网络设备S发送所述报文。网络设备S发送所述报文时，将根据DA字段的内容，按照最长匹配规则确定报文的下一跳网络设备。DA字段中包括BLOCK和依次 排列的多个USID，BLOCK与第一个USID组合，就构成与该第一个USID对应的SID。因而，确定出的下一跳网络设备为第一个USID对应的网络设备。
参见图9所示的报文结构，结合图1所示的应用场景进行举例说明，网络设备S根据报文的报文头中DA字段中的内容，按照最长匹配规则查询本地路由表。具体的，由BLOCK+USID1组成的部分为A:1:01:11，与路由表中的表项进行匹配，与SID1匹配成功，即网络设备S确定下一跳网络设备为网络设备1，从而将包括段列表的报文向网络设备1发送。
网络设备1接收所述报文后，根据DA字段的内容，按照最长匹配规则查询本地段标识表(local SID table)，确定报文处理动作。DA字段中包括BLOCK和依次排列的多个USID，BLOCK与第一个USID组合，就构成与该第一个USID对应的SID。因而，确定出的报文处理动作为第一个USID中功能字段对应的报文处理动作，也可以称为第一个USID对应的报文处理动作。
参见图9所示的报文结构，结合图1所示的应用场景进行举例说明，包括段列表的报文由网络设备S发送至网络设备1，网络设备1根据报文中的DA字段，按照最长匹配规则查询本地段标识表，由BLOCK+USID1组成的部分与本地段标识表中的表项匹配成功，则网络设备1执行该USID1对应的报文转发处理动作。
可选的，该报文转发处理动作可以包括对DA字段进行更新。具体的，网络设备1将所述DA字段中BLOCK之后的部分，删除一个USID长度的比特，其余部分向前移动，末尾空白部分填充全0。
可选的，网络设备1在完成上述对DA字段的更新之后，进一步判断所述DA字段中BLOCK之后的部分是否全部为0。如果不是全部为0，则网络设备1根据DA字段中的内容，按照最长匹配规则查询本地路由表，继续转发所述报文。
可选的，所述报文到达转发路径上的其他中间节点之后，其他中间节点对所述报文的处理动作可能与网络设备1的上述报文处理动作相同。也就是说，转发路径上的多个中间节点对所述报文的处理动作都包括对DA字段进行更新，以及判断所述DA字段中BLOCK之后的部分是否全部为0。
结合图1所示的应用场景进行举例说明，网络设备1在对DA字段进行更新，DA字段中BLOCK之后的USID1被删除，其余部分向前移动，末尾空白部分填充全0。此时，DA字段中包括BLOCK、USID2及USID3，所述报文的结构如图11所示。网络设备1判断DA字段中BLOCK之后的部分不是全部为0，则继续转发所述报文。此时DA字段的内容按照最长匹配规则与网络设备2的SID匹配成功，即BLOCK+USID2组成的部分与网络设备2的SID匹配成功，网络设备1向网络设备2发送所述报文。
所述报文到达网络设备2，网络设备2根据报文中的DA字段，按照最长匹配规则查询本地段标识表，由BLOCK+USID2组成的部分匹配成功，执行相应的报文处理动作。并且，网络设备2更新DA字段，即将DA字段中USID2删除，其余部分向前移动，末尾空白部分填充全0。此时，DA字段中包括BLOCK及USID3，所述报文的结构如图12所示。网络设备2判断DA字段中BLOCK之后的部分不是全部为0，则继续转发所述报文。此时DA字段的内容按照最长匹配规则与网络设备3的SID匹 配成功，即BLOCK+USID3组成的部分与网络设备3的SID匹配成功，网络设备2向网络设备3发送所述报文。
网络设备3接收报文。可选的，网络设备3在完成对DA字段的更新之后，进一步判断所述DA字段中BLOCK之后还存在剩余的标识，如果不存在剩余的标识，例如，BLOCK之后的部分全部为0，则网络设备3需要继续向DA字段中拷贝标识。执行该拷贝动作的网络设备可以称为拷贝节点，即网络设备3为拷贝节点。
拷贝节点根据第一指针的值确定第一标识在所述第一元素中的位置。其中，第一指针为PI指针，第一标识为当前待添加的标识。可选的，在根据PI指针的值确定当前待添加的标识之前，网络设备3先根据SL指针的值确定当前元素。网络设备3进而根据PI指针的值在当前元素中确定当前待添加的标识。根据PI指针的值确定当前待添加的标识。当前待添加的标识即所述第一标识。
结合图1所示的应用场景进行举例说明，网络设备3根据报文中的DA字段，按照最长匹配规则查询本地段标识表，由BLOCK+USID3组成的部分匹配成功，执行相应的转发动作。并且，网络设备3更新DA字段，即将DA字段中USID3删除，其余部分向前移动，末尾空白部分填充全0。此时，DA字段中仅包括BLOCK。网络设备3判断DA字段中BLOCK之后的部分全部为0，即需要向DA字段中添加USID。此时，网络设备3根据SL指针的值确定当前元素。例如，报文中的SL指针的值可以为4，网络设备3确定当前元素为段列表中的第一个元素。进而，网络设备3根据PI指针的值为3，确定当前待添加的标识为当前元素中的第4个USID，即USID4。
拷贝节点将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的报文头中。可选的，以所述第一标识为起始的至少一个标识可以是至少一个USID时，所述报文头可以是IPv6报文头。拷贝节点确定所述至少一个USID的数量。
可选的，拷贝节点确定(128-L BLOCK)/L USID的整数部分，将该整数部分的值作为所述至少一个USID的数量。
可选的，拷贝节点比较(128-L BLOCK)/L USID的整数部分以及当前元素中未添加至DA字段中的剩余USID的数量，将两者中较小的值作为所述至少一个USID的数量。
可选地，拷贝节点在DA字段添加所述至少一个USID之后，修改所述报文中PI指针的值，以使得修改后的PI指针的值指向段列表中的当前待添加的标识，该当前待添加的标识可以称为第三标识，该第三标识可以是所述至少一个USID中最后一个USID在段列表中下一个标识。
可选的，所述待添加的标识可以是USID，该USID位于当前元素在段列表中的后一个元素中，也就是说，当前元素中的所有USID已经添加至DA字段中。此时，该USID可以是所述后一个元素中的第一个USID。此时，修改后的PI指针的值用于指示该USID在后一个元素中的位置，例如，修改后的PI指针的值可以是0。
可选的，当前元素中的所有标识已经添加至DA字段之后，拷贝节点修改所述报文中SL指针的值，以使得修改后的SL指针的值指向当前元素在段列表中的后一个元素。
结合图1所示的应用场景进行举例说明，网络设备3确定当前待添加的标识为USID4。并且，网络设备3确定当前元素中未添加至DA字段中的剩余USID的数量 为1，即只有USID4。由于USID的长度为32比特，BLOCK的长度为32比特，(128-L BLOCK)/L USID的整数部分为3，大于剩余USID的数量。因而，网络设备3确定待添加至DA字段中的至少一个USID的数量为1。网络设备3将USID4添加至报文的IPv6报文头的DA字段中，此时的报文结构如图14所示。并且，由于当前元素中的所有USID已经被添加至DA字段中，网络设备3修改报文中SL指针的值，将SL指针的值减1，修改后的SL指针的值为3，指向段列表中的第二个元素。并且，网络设备3修改PI指针的值，修改后的PI指针的值为0，指向第二个元素中的第一个USID，即USID5。
网络设备3发送所述报文。所述报文继续沿转发路径转发，转发路径上的中间节点继续对报文中的DA字段进行更新。当DA字段中的标识处理完毕，即DA字段中BLOCK之后不存在剩余的标识时，转发路径上的拷贝节点继续对报文中的DA字段进行更新。例如，当DA字段中添加的至少一个USID被处理完毕以后，拷贝节点将根据PI指针的值继续向报文的DA字段中添加以当前待添加的标识为起始的至少一个标识。
可选的，以当前待添加的标识为起始的至少一个标识可以是USID，此时，拷贝节点的处理过程与以上描述类似，在此不再赘述。
可选的，所述至少一个USID是多个USID。当所述至少一个USID是多个USID时，多个USID在所述段列表中彼此相邻。
可选地，拷贝节点在DA字段添加所述至少一个USID之后，修改所述报文中PI指针的值，以使得修改后的PI指针的值指向当前待添加的标识，此时，当前待添加的标识是所述至少一个USID中最后一个USID在段列表中下一个标识。
可选的，所述当前待添加的标识可以是USID，该USID与所述至少一个USID可以都位于当前元素中。此时，修改后的PI指针的值用于指示该USID在当前元素中的位置。
可选的，所述当前待添加的标识可以是USID，该USID位于当前元素在段列表中的后一个元素中，也就是说，当前元素中的所有USID已经添加至DA字段中。此时，该USID可以是所述后一个元素中的第一个USID。此时，修改后的PI指针的值用于指示该USID在后一个元素中的位置，例如，修改后的PI指针的值可以是0。
可选的，当前元素中的所有标识已经添加至DA字段之后，拷贝节点修改所述报文中SL指针的值，以使得修改后的SL指针的值指向当前元素在段列表中的后一个元素。
网络设备4接收报文，根据DA字段中的BLOCK+USID4对所述报文进行处理。并且，网络设备4更新DA字段，将DA字段中USID4删除，其余部分向前移动，末尾空白部分填充全0。此时，DA字段中仅包括BLOCK。则网络设备4为拷贝节点。网络设备4判断DA字段中BLOCK之后的部分全部为0，则网络设备4继续向报文的DA字段中添加标识。网络设备4根据报文中SL指针的值确定当前元素为段列表中的第二个元素，并且根据PI指针的值确定当前待添加的标识为第二个元素中的第一个USID，即USID5。网络设备4确定(128-L BLOCK)/L USID的整数部分为3，确定当前元素中未添加至DA字段中的剩余USID的数量为4，将两者中较小的值，即3作 为添加至DA字段中的USID的数量。从而，网络设备4将以USID5为起始的3个USID添加至DA字段中，3个USID为USID5,USID6和USID7，此时的报文结构如图15所示。并且，网络设备4修改PI指针的值，以使得PI指针的值指向待添加的USID，即USID8。
此后，报文继续经过网络设备5、网络设备6、网络设备7转发至网络设备8，这些网络设备的报文处理动作分别与网络设备1、网络设备2、网络设备3和网络设备4类似，其中，网络设备7也是拷贝节点，在此不再赘述。
可选的，以当前待添加的标识为起始的至少一个标识可以是长度为128比特的SID，结合以上描述，此时在段列表中该SID的前一个USID中包括提示标志。当拷贝节点处理所述前一个USID时，能够根据所述提示标志，确定该USID的后一个标识为长度为128比特的SID。可选的，所述拷贝节点在所述报文的DA字段中添加长度为128比特的SID。也就是说，所述DA字段中的BLOCK部分也将被覆盖。
可选地，拷贝节点在DA字段添加所述至少一个USID之后，修改所述报文中PI指针的值，以使得修改后的PI指针的值指向当前待添加的标识，此时，当前待添加的标识是所述至少一个USID中最后一个USID在段列表中下一个标识。
可选的，所述当前待添加的标识可以是长度为128比特的SID。此时，由于SID占据一个元素中的全部空间，例如，修改后的PI指针的值可以是0。
例如，网络设备8也是拷贝节点。网络设备8接收报文，根据DA字段中的BLOCK+USID8对报文进行处理，发现USID8包括提示标志，确定USID8在段列表中的下一个标识为长度为128比特的SID。网络设备8根据报文中SL指针的值确定当前元素为段列表中的第三个元素，将该元素中的SID添加至DA字段中，即将SID9添加至DA字段中，此时的报文构如图16所示。
结合以上描述，所述报文中可以仅包括XL指针。可选的，当所述报文中仅包括XL指针时，作为报文的转发路径的入口节点，网络设备S在所述DA字段中添加至少一个标识，该标识可以是USID。拷贝节点根据XL指针的值确定第一标识在段列表中的位置，并将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的报文头中，具体的，拷贝节点将以所述第一标识为起始的至少一个标识添加至DA字段中。拷贝节点修改所述报文中XL指针的值，以使得修改后的XL指针的值仍然指向段列表中的当前待添加的标识。可选的，当所述报文中仅包括XL指针时，以所述第一标识为起始的至少一个标识为一个标识，即第一标识，也就是说，每次添加至所述DA字段中的标识的数量可以为1个，则XL指针在段列表中指向的位置每次偏移一个标识的长度。
当所述报文中仅包括XL指针时，结合图1所示的应用场景进行举例说明。例如，网络设备S在DA字段中添加SID的BLOCK部分，在DA字段的BLOCK之后，添加1个USID，即USID1。修改XL指针的值可以在添加USID之前进行，也可以在添加USID之后进行。例如，当修改XL指针的值在添加USID之后进行时，网络设备S设置报文中的XL指针指向USID2，即指示当前待添加的标识为段列表中的USID2。网络设备S根据报文的报文头中DA字段中的内容，按照最长匹配规则查询本地路由表。具体的，由BLOCK+USID1组成的部分为A:1:01:11，与路由表中的表 项进行匹配，与SID1匹配成功，即网络设备S确定下一跳网络设备为网络设备1，从而将包括段列表的报文向网络设备1发送。网络设备1根据报文中的DA字段，按照最长匹配规则查询本地段标识表，由BLOCK+USID1组成的部分与本地段标识表中的表项匹配成功，则网络设备1执行该USID1对应的报文处理动作。当以所述第一标识为起始的至少一个标识为一个标识时，段列表中每个标识对应的网络设备均为拷贝节点，即网络设备1也是拷贝节点。网络设备1根据XL指针的值确定当前待添加的USID2在段列表中的位置，并将USID2拷贝至DA字段中。网络设备1修改所述报文中XL指针的值，修改后的XL指针指向USID3，即指示当前待添加的标识为段列表中的USID3。此后，报文继续经过网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9转发至网络设备10，这些网络设备的报文处理动作分别与网络设备1类似，在此不再赘述。
可选的，段列表中可以同时包括USID和其他类型的标识。所述其他类型的标识可以是MPLS标签或者IPv4地址，也就是说，采取USID的段列表中还可以夹杂有MPLS标签或者IPv4地址。在报文的转发路径所经过的网络设备中，某些网络设备可能不支持SRv6，但能够支持MPLS，或者能够支持IPv4，此时，段列表中直接存放对应这些网络设备的MPLS标签或者IPv4地址。从而，提高网络兼容性，提升网络效率。结合图1所示的应用场景，网络设备S向网络设备10发送报文，报文的转发路径依次经过网络设备1、网络设备2、网络设备3、网络设备4、网络设备5、网络设备6、网络设备7、网络设备8、网络设备9。其中，网络设备3、网络设备4、网络设备5和网络设备6不支持SRv6，但能够支持MPLS。
在段列表中，USID与MPLS标签和/或IPv4地址按照所对应的网络设备在转发路径上的顺序依次排列。其中，每个MPLS标签的长度可以为32比特，每个IPv4地址的长度也可以为32比特。MPLS标签或者IPv4地址的长度可以与USID的长度相同，也可以与USID的长度不同。图8示出了此时的段列表的结构，由于网络设备3、网络设备4、网络设备5和网络设备6不支持SRv6，但能够支持MPLS时，段列表中可以存放分别对应于这些网络设备的MPLS标签，即M3、M4、M5和M6。段列表中同时存放分别对应于其他网络设备的USID或SID。MPLS标签的长度均为32比特，与USID长度相同。并且，这些MPLS标签可以和USID共同存放在一个元素中，如图8所示，段列表中第一个元素中USID1,USID2,M3和M4，第二个元素中存放M5,M6,USID7和USID8。IPv4地址的存放方式与MPLS标签类似，在此不再赘述。
可选的，当段列表中包括MPLS标签和/或IPv4地址时，网络设备S在报文中添加切换标志，该切换标志可以位于段列表中。例如，当段列表中包括连续排列的多个MPLS标签或IPv4地址时，该切换标志可以位于段列表中的特定标识中，该特定标识例如称为第二标识。该第二标识可以是第一个MPLS标签或IPv4地址的前一个USID中。或者，该切换标志可以是一个独立的标识，该独立的标识添加在最后一个USID和第一个MPLS标签或IPv4地址之间。该切换标志用于指示段列表中的后一个标识中将包括MPLS标签和/或IPv4地址，从而，当网络设备读取到所述前一个USID时，就能确定该USID在段列表中的后一个标识中将包括MPLS标签和/或IPv4地址。具体过程将在下文中详细描述。
可选的，当网络设备S在所述DA字段中添加至少一个标识时，网络设备S将判断被添加的至少一个标识中的每个标识中是否包括所述切换标志，如果某个标识中包括切换标志，则网络设备S在向DA字段中添加完这个标识以后，不再向DA字段中添加这个标识的后一个标识。此时，添加到DA字段中的至少一个标识全部为USID，而不包括其他类型的标识。
可选的，当段列表中包括MPLS标签和/或IPv4地址时，网络设备S还在报文中添加数量标志，该数量标志的值用于指示段列表中MPLS标签和/或IPv4地址的数量。该数量标志的位置可以在报文头中，所述报文头可以是SRH或IPv6报文头。例如，该数量标志可以位于SRH的特定字段中，或者，该数量标志可以位于IPv6报文头的DA字段中。该数量标志也可以位于段列表。例如，当段列表中包括连续排列的多个MPLS标签或IPv4地址时，该数量标志可以位于第一个MPLS标签或IPv4地址的前一个USID中。此时，PI指针用于指示不同的USID、MPLS标签或IPv4地址在该元素中的位置。
可选的，所述切换标志和所述数量标志可以为同一个标志，也就是说，所述数量标志同时起到切换标志的作用。此时，段列表中包括连续排列的多个MPLS标签或IPv4地址，该数量标志可以位于第一个MPLS标签或IPv4地址的前一个USID中。
结合图10进行举例说明。图10示出了添加有段列表和PI指针的报文的结构，并且段列表中包括MPLS标签。并且，网络设备S在DA字段中添加SID的BLOCK部分。在DA字段的BLOCK之后，添加2个USID和1个MPLS标签。如图10所示，2个USID为USID1,USID2，1个MPLS标签为M3。PI指针的值为3，表示段列表的该元素中前3个标识已经添加至DA字段中。根据PI指针的值能够确定该元素中待添加的标识，即M3，具体内容将在下文详细描述。
当报文的段列表中还包括其他类型的标识，例如MPLS标签和/或IPv4地址时，转发路径上的中间节点可以将其他类型的标识拷贝至报文中的转发标识栈中，该转发标识栈用于指导报文转发。执行上述拷贝行为的中间节点可以称为拷贝节点。
可选的，转发路径上的拷贝节点在处理当前USID时，能够通过上述切换标志或数量标志确定段列表中的后一个标识中将包括MPLS标签或IPv4地址。此时，当前待添加的标识应当为第一个MPLS标签或IPv4地址。拷贝节点进而根据PI指针的值确定第一个MPLS标签或IPv4地址。
如果所述当前USID为DA字段中的最后一个USID，即DA字段中该USID之后不存在其他标识，则拷贝节点可以根据PI指针的值在段列表中直接确定第一个MPLS标签或IPv4地址。
如果所述当前USID不是DA字段中的最后一个USID，即DA字段中该USID之后还存在其他标识，则说明已经有部分MPLS标签或IPv4地址已经被添加至DA字段中，并且第一个MPLS标签或IPv4地址已经被添加至DA字段中。可选的，拷贝节点可以分别获取已经被添加至DA字段中的其他标识，以及未被添加至DA字段中的其他标识。可选的，拷贝节点也可以确定已经被添加至DA字段中的MPLS标签或IPv4地址的数量N，N为整数，再可以根据PI指针的值和数量N对PI指针的值进行校正，根据校正后的PI指针的值在段列表中确定第一个MPLS标签或IPv4地址。具 体的，拷贝节点通过将PI指针的值减去数量N的值，对PI指针的值进行校正。上述过程也可以看作是段列表中PI指针的回退。
参见图13所示的报文结构，报文中DA字段包括BLOCK、USID2和M3，并且USID2中包括数量标志，数量标志的值可以为4。并且，报文中PI指针的值可以为3。结合图1所示的应用场景进行举例说明，上述拷贝节点可以是网络设备2。网络设备2根据报文中的DA字段，按照最长匹配规则查询本地段标识表，由BLOCK+USID2组成的部分匹配成功，执行相应的转发动作。并且，网络设备2在处理当前USID2时，通过USID2中包括的数量标志确定，USID2在段列表中的后一个标识中将包括MPLS标签，并且MPLS标签的数量为4个。此时，当前待添加的标识应当为第一个MPLS标签。
网络设备2进而判断当前的USID2不是DA字段中的最后一个USID，DA字段中USID2之后还有32个非0比特，USID2之后还有1个MPLS标签，也就是说第一个MPLS标签已经被添加至DA字段中。网络设备2根据PI指针的值为3，结合已经被添加至DA字段中的MPLS标签的数量为1，确定校正后的PI指针的值应当为2，根据校正后的PI指针的值，确定第一个MPLS标签应为当前元素中的第3个标识，即M3。
可选的，当以所述第一标识为起始的至少一个标识为至少一个其他类型的标识，例如MPLS标签或IPv4地址时，拷贝节点将这些其他类型的标识添加至所述第二报文头中以形成转发标识栈，例如MPLS标签栈或者IPv4地址栈。
结合以上描述，当部分其他类型的标识已经被添加至DA字段中时，可选的，拷贝节点可以分别获取已经被添加至DA字段中的其他标识，以及未被添加至DA字段中的其他标识，并将这两部分其他标识共同添加至所述第二报文头中以形成转发标识栈；可选的，拷贝节点也可以根据根据校正后的PI指针的值在段列表中确定第一个其他类型的标识的位置，以从段列表中获取所有其他类型的标识。
拷贝节点确定所述至少一个MPLS标签或IPv4地址的数量。可选的，中间节点将所述数量标志的值作为所述至少一个MPLS标签或IPv4地址的数量。
所述至少一个MPLS标签或IPv4地址对应至少一个支持MPLS或IPv4的网络设备，在经过这些网络设备之后，报文可能再次进入SRv6网络。此时，在段列表中，所述至少一个MPLS标签或IPv4地址之后还存在一个或多个USID，这些USID也需要被拷贝至报文中IPv6报文头的DA字段中。可选的，这些USID可以由中间节点拷贝至DA字段中。可选的，这些USID也可以由所述至少一个支持MPLS或IPv4的网络设备中的最后一个网络设备拷贝至DA字段中。
当这些USID可以由中间节点拷贝至DA字段中时，可选的，拷贝节点在将这些USID拷贝至DA字段之后，修改所述报文中PI指针的值，以使得修改后的PI指针的值指向段列表中的其他标识，该其他标识例如可以称为第三标识。该第三标识可以是上述被拷贝至DA字段中的这些USID中最后一个USID在段列表中的下一个标识。该第三标识可以与上述最后一个USID位于段列表中的相同元素中，也可以与上述最后一个USID位于段列表中的不同元素中。例如，当最后一个USID所在的元素为第一元素，第三标识所在的元素为第二元素时，该第一元素与第二元素可以相同，也 可以不同。可选的，当第一元素与第二元素不同时，拷贝节点还修改所述报文中SL指针的值，以使得修改后的SL指针指向所述第二元素。例如，该第二元素可以是第一元素在段列表中的后一个元素。
结合图1所示的应用场景进行举例说明，上述拷贝节点可以是网络设备2，网络设备2接收到的报文的结构如图13所示。网络设备2确定第一个MPLS标签应为当前元素中的第3个标识，即M3。并且，网络设备2根据数量标志的值为4，确定待添加至DA字段中的至少一个MPLS标签的数量为4。网络设备2在报文的IPv6报文头外建立MPLS报文头，该MPLS报文头包括转发标识栈，即MPLS标签栈。网络设备2将以M3为起始的4个MPLS标签添加至MPLS标签栈中。这4个MPLS标签包括M3、M4、M5和M6。并且网络设备2将段列表中M6之后的至少一个USID拷贝至DA字段中，具体的，网络设备2将USID7和USID8拷贝至DA字段中。并且，网络设备2修改SL指针的值，修改后的SL指针的值为2，指向段列表中的第三个元素，网络设备2修改PI指针的值，修改后的PI指针的值为0，指向第三个元素中的第1个标识，即SID9。此时，报文的结构如图17所示。
网络设备2根据MPLS报文头中MPLS标签栈的栈顶标签，即M3，向网络设备3转发报文。报文到达网络设备3，MPLS标签栈顶的M3弹出，M4成为栈顶标签。网络设备3根据M4，向网络设备4转发报文。随后报文依次到达网络设备4、网络设备5和网络设备6，具体过程与以上描述类似，在此不再赘述。在网络设备5或网络设备6处，报文中的MPLS报文头被剥离。网络设备6同时支持MPLS和SRv6。网络设备6根据报文的IPv6报文头中的DA字段继续转发报文，参见图17所示的报文结构，DA字段中包括BLOCK、USID7和USID8。从而，网络设备6将报文向网络设备7转发。具体过程与以上描述类似，在此不再赘述。
以上通过MPLS标签的处理过程进行举例说明，IPv4地址的处理过程与以上描述类似，在此不再赘述。
本发明实施例提供了一种转发报文的方法。图18示出了该方法的方法流程图。该方法涉及网络设备401和网络设备402。其中网络设备401可以是网络中的网络入口设备，用于在报文中封装对应报文的转发路径的段列表，例如，图1所示的网络设备S。网络设备402可以是网络中的转发设备，具体的，网络设备402是上述实施例中的拷贝节点，例如，图1所示的网络设备3、网络设备4、网络设备7、网络设备8或网络设备9，或者，图1所示的网络设备2。该方法的步骤包括：
S410，网络设备401接收报文。
S420，网络设备401获得段列表。所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的标识对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的元素，所述元素包括所述多个标识中的相邻的至少两个标识。
S430，网络设备401在报文中添加所述段列表，所述段列表包括第一指针，所述第一指针的值用于指示第一标识在元素中的位置，所述第一标识为所述至少两个标识中的一个。
S440，网络设备401发送所述报文。
网络设备401可以是网络中的网络入口设备，并且，网络设备401是所述报文的转发路径的入口节点，例如，图1所示的网络设备S。具体过程可以参照上述实施例中对网络设备S的描述，相似之处在此不再赘述。
S450，网络设备402接收报文。所述报文的报文头包括用于转发所述报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针。
S460，网络设备402根据所述第一指针的值确定所述第一标识在所述第一元素中的位置。
S470，网络设备402将以所述第一标识为起始的至少一个标识拷贝至所述报文的报文头中。
S480,网络设备402发送所述报文。
网络设备402可以是所述报文的转发路径的拷贝节点，即网络设备402是拷贝至少一个标识至报文中的中间节点。网络设备402拷贝的至少一个标识可以是USID，也可以是MPLS标签或IPv4地址。具体的，结合图1所示的应用场景，网络设备402可以是1中的网络设备2、网络设备3、网络设备4、网络设备7、网络设备8或网络设备9。具体过程可以参照上述实施例中对网络设备2、网络设备3、网络设备4、网络设备7、网络设备8或网络设备9的描述，相似之处在此不再赘述。
在实际网络中，报文的转发路径可以由控制器生成，也可以由转发路径的入口节点生成。当控制器生成报文的转发路径时，控制器也将生成对应该转发路径的段列表，该段列表可以是包括USID的段列表。控制器将该段列表向转发路径的入口节点发送。转发路径的入口节点在接收到报文以后，从设备内部存储的若干转发路径中确定所述报文的转发路径，并确定对应该转发路径的段列表。将所述段列表封装至所述报文中，用于转发所述报文。
本发明实施例提供了一种转发报文的方法。图19示出了该方法的方法流程图。该方法涉及网络设备301，网络设备302和网络设备303。其中网络设备301可以是网络中的控制器，用于计算报文的转发路径，并生成对应所述转发路径的段列表。网络设备302可以是网络入口设备，用于在报文中封装段列表，例如，图1所示的网络设备S。网络设备303可以是网络中的转发设备，用于根据段列表转发报文，具体的，网络设备303可以上述实施例中的拷贝节点，例如，图1所示的网络设备2、网络设备3、网络设备4、网络设备7、网络设备8或网络设备9。该方法的步骤包括：
S310，网络设备301确定报文的转发路径，所述转发路径包括多个网络设备。
网络设备301可以是网络中的控制器。控制器计算用于转发报文的转发路径。
S315，网络设备301生成对应于所述转发路径的所述段列表，所述段列表包括依次排列的所述多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识。
可选的，网络设备301获取多个段标识，所述多个段标识对应于所述多个网络设 备中的至少一个网络设备或所述转发路径中的至少一个链路。例如，控制器获得转发路径上的各个网络设备的SID。网络设备301根据所述多个段标识获得多个标识，所述多个标识一一映射至所述多个段标识。为了减少SID的长度，控制器可以将多个SID转换为多个USID，多个USID一一映射至多个SID。具体方法包括省略SID的BLOCK部分和/或将SID的功能字段设置为压缩的格式。具体过程可以参照对步骤S420的描述，相似之处不再赘述。
网络设备301生成对应于所述转发路径的所述段列表，所述段列表包括依次排列的所述多个标识，所述段列表包括长度为128比特的元素，所述元素包括所述多个标识中的相邻的至少两个标识。例如，控制器将多个USID代替多个SID，放入段列表中，从而减少段列表的长度。段列表中的空间可以被划分为多个元素，每个元素的长度可以是128比特。每个元素中可以存入至少两个USID。具体过程可以参照对步骤S420的描述，相似之处不再赘述。
S320，网络设备301向网络设备302发送所述段列表。
网络设备302是网络中的网络设备，并且，网络设备302是所述报文的转发路径的入口节点，例如，图1所示的网络设备S。网络设备302获得段列表，所述段列表对应于报文的转发路径，所述段列表包括依次排列的多个标识，所述多个标识中的每一个标识对应于所述多个网络设备中的一个网络设备。
S325，网络设备302接收报文。
作为转发路径的入口节点，网络设备302接收报文，并且确定报文的转发路径。可选的，网络设备302可以从存储的多个转发路径中查找出用于转发所述报文的转发路径，从而确定所述报文的转发路径。所述存储的多个转发路径可以是网络设备302从所述控制器接收到的。
S330，网络设备302在报文中添加所述段列表，所述段列表包括所述第一指针，所述第一指针的值用于指示第一标识在所述元素中的位置，所述第一标识为所述至少两个标识中的一个。
步骤S330的具体过程可以参照对步骤S430的描述，相似之处不再赘述。
S335，网络设备302发送所述报文。
步骤S335的具体过程可以参照对步骤S440的描述，相似之处不再赘述。
S340，网络设备303接收报文。
步骤S340的具体过程可以参照对步骤S450的描述，相似之处不再赘述。
S345，网络设备303根据所述第一指针的值确定所述第一标识在所述第一元素中的位置。所述第一指针为以上描述的新增的PI指针。
步骤S345的具体过程可以参照对步骤S460的描述，相似之处不再赘述。
S350，网络设备303将以所述第一标识为起始的至少一个标识拷贝至所述报文的报文头中。
步骤S350的具体过程可以参照对步骤S470的描述，相似之处不再赘述。
S355,网络设备303发送所述报文。
步骤S355的具体过程可以参照对步骤S480的描述，相似之处不再赘述。
图20是本申请实施例提供的一种设备400的结构示意图。图1中任一网络设备 可以通过图20所示的设备来实现。图18所示实施例中的网络设备401、网络设备402，以及图19所示实施例中的网络设备301、网络设备302和网络设备303可以通过图20所示的设备来实现。参见图20，该设备2000包括至少一个处理器2001，通信总线2002以及至少一个通信接口2004，可选地，该设备2000还可以包括存储器2003。
处理器2001处理器1502可以是中央处理器(central processing unit，CPU)、通用处理器，数字信号处理器(digital signal processor，DSP)、专用集成电路(application-specific integrated circuit，ASIC)、现场可编程门阵列(field programmable gate array，FPGA)或者其他可编程逻辑器件、晶体管逻辑器件、硬件部件或者其任意组合。其可以实现或执行结合本发明实施例公开内容所描述的各种逻辑方框、模块和电路。所述处理器也可以是实现计算功能的组合，例如包括一个或多个微处理器组合，DSP和微处理器的组合等等。。处理器可以用于生成段列表，或者对接收到的报文进行处理，并将处理后的报文通过通信接口继续转发。以实现本申请实施例中提供的方法。
比如，当网络中的控制器或网络入口设备通过图20所示的设备来实现时，该处理器可以用于生成段列表，以便于网络设备根据段列表对相应的报文进行转发处理，具体功能实现可参考方法实施例中控制器或网络入口设备的处理部分。比如，当图1中的网络入口设备通过图20所示的设备来实现时，该处理器可以用于在接收到的报文中添加段列表，以便于后续网络设备根据报文中的段列表对报文进行转发处理，具体功能实现可参考方法实施例中网络入口设备的处理部分。又比如，当图1中网络中的转发设备通过图20所示的设备来实现时，该处理器可以用于根据报文中的段列表对报文进行转发处理，具体功能实现可参考方法实施例中转发设备的处理部分。
通信总线2002用于在处理器2001、通信接口2004和存储器、2003之间传送信息。总线可以是外设部件互连标准(peripheral component interconnect，简称PCI)总线或扩展工业标准结构(extended industry standard architecture，简称EISA)总线等。所述总线可以分为地址总线、数据总线、控制总线等。为便于表示，图20中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。
存储器2003可以是只读存储器(read-only memory，ROM)或可存储静态信息和指令的其它类型的静态存储设备，随机存取存储器(random access memory，RAM)或者可存储信息和指令的其它类型的动态存储设备，也可以是电可擦可编程只读存储器(electrically erasable programmable read-only memory，EEPROM)、只读光盘(compact disc read-only Memory，CD-ROM)或其它光盘存储、光碟存储(包括压缩光碟、激光碟、光碟、数字通用光碟、蓝光光碟等)、磁盘存储介质或者其它磁存储设备、或者能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其它介质，但不限于此。存储器2003可以是独立存在，通过通信总线2002与处理器2001相连接。存储器403也可以和处理器2001集成在一起。
可选地，存储器2003用于存储执行本申请方案的程序代码或指令，并由处理器2001来控制执行。处理器2001用于执行存储器2003中存储的程序代码。程序代码中 可以包括一个或多个软件模块。可选地，处理器2001自身也可以存储执行本申请方案的程序代码或指令。
通信接口2004，使用任何收发器一类的装置，用于与其它设备或通信网络通信，通信网络可以为以太网、无线接入网(RAN)或无线局域网(wireless local area networks，WLAN)等。在本申请实施例中，通信接口2004可以用于接收分段路由网络中的其他节点发送的报文，也可以向分段路由网络中的其他节点发送报文。通信接口2004可以为以太接口(Ethernet)接口、快速以太(Fast Ethernet，FE)接口、千兆以太(Gigabit Ethernet，GE)接口或异步传输模式(Asynchronous Transfer Mode，ATM)接口。
在具体实现中，作为一种实施例，设备2000可以包括多个处理器，例如图20中所示的处理器2001和处理器2005。这些处理器中的每一个可以是一个单核(single-CPU)处理器，也可以是一个多核(multi-CPU)处理器。这里的处理器可以指一个或多个设备、电路、和/或用于处理数据(例如计算机程序指令)的处理核。
图21是本申请实施例提供的一种设备2100的结构示意图。图1中除控制器外的任一网络设备可以通过图21所示的设备来实现。图18所示实施例中的网络设备401、网络设备402，以及图19所示实施例中的网络设备302和网络设备303可以通过图21所示的设备来实现。参见图21所示的设备结构示意图。设备2100包括主控板和一个或多个接口板，主控板与接口板通信连接。主控板也称为主处理单元(main processing unit，MPU)或路由处理卡(route processor card)，主控板负责对设备2100中各个组件的控制和管理，包括路由计算、设备管理和维护功能。接口板也称为线卡(line processing unit，LPU)或线卡(line card)，用于转发数据。在一些实施例中，设备2100也可以包括交换网板，交换网板与主控板、接口板通信连接，交换网板用于转发接口板之间的数据，交换网板也可以称为交换网板单元(switch fabric unit，SFU)。接口板包括中央处理器、存储器、转发芯片和物理接口卡(physical interface card，PIC)。中央处理器与存储器、网络处理器和物理接口卡分别通信连接。存储器用于存储转发表。转发芯片用于基于存储器中保存的转发表转发接收到的数据帧，如果数据帧的目的地址为设备2100的地址，则将该数据帧上送CPU处理；如果数据帧的目的地址不是设备2100的地址，则根据该目的地址从转发表中查找到该目的地址对应的下一跳和出接口，将该数据帧转发到该目的地址对应的出接口。转发芯片可以是网络处理器(network processor，NP)。PIC也称为子卡，可安装在接口板上，负责将光电信号转换为数据帧并对数据帧进行合法性检查后转发给转发芯片处理。在一些实施例中，中央处理器也可执行转发芯片的功能，比如基于通用CPU实现软件转发，从而接口板中不需要转发芯片。主控板、接口板、交换网板之间的通信连接可以通过总线来实现。在一些实施例中，转发芯片可以通过专用集成电路(application-specific integrated circuit，ASIC)或现场可编程门阵列(field programmable gate array，FPGA)实现。
在逻辑上，设备2100包括控制面和转发面，控制面包括主控板和中央处理器，转发面包括执行转发的各个组件，比如存储器、PIC和NP。控制面执行路由器、生成转发表、处理信令和协议报文、配置与维护PE1的状态等功能，控制面将生成的 转发表下发给转发面，在转发面，NP基于控制面下发的转发表对设备2100的PIC收到的报文查表转发。控制面下发的转发表可以保存在存储器中。在有些实施例中，控制面和转发面可以完全分离，不在同一设备上。
图22示出了上述实施例中所涉及的网络设备的一种可能的结构示意图，网络设备1400可以实现上述实施例中网络设备402或网络设备303的功能。参阅图20，该网络设备1400包括：接收单元1401、处理单元1402和发送单元1403。这些单元可以执行上述方法中网络设备402或网络设备303的相应功能。举例来说，
接收单元1401，用于用于接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的标识对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针和第二指针。
处理单元1402，用于根据所述第二指针的值确定所述第一元素在所述段列表中的位置，根据所述第一指针的值确定所述第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文。
发送单元1403，用于发送所述第二报文。
网络设备1400也可以通过图20所示的设备来实现。此时，网络设备1400包括：至少一个处理器、通信总线以及至少一个通信接口。可选的，网络设备1400还可以包括存储器。
在具体实施例中，网络设备1400中的处理器用于通过通信接口接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针；根据所述第一指针的值确定所述第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文；通过通信接口1503发送所述第二报文。该处理器的详细处理过程请参考上述实施例中的过程S450,S460,S470,S480以及过程S340,S345,S350,S355的详细描述，这里不再赘述。
网络设备1400中的通信接口用于网络设备1400通过网络系统接收和发送报文。具体的过程请参考上述实施例中S450,S480以及S340,S355的详细描述，这里不再赘述。
网络设备1400也可以通过图21所示的设备来实现。此时，网络设备1400包括主控板和一个或多个接口板，主控板与接口板通信连接。具体参见上述实施例中对网络设备2100的描述，在此不再赘述。
图23示出了上述实施例中所涉及的网络设备的一种可能的结构示意图，网络设备1600可以实现上述实施例中网络设备401或网络设备302的功能。参阅图23，该网络设备1600包括：接收单元1601、处理单元1602和发送单元1603。这些单元可 以执行上述方法中网络设备401或网络设备302的相应功能。举例来说，
接收单元1601，用于接收第一报文。
处理单元1602，用于获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的标识对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个。
发送单元1603，用于发送所述第二报文。
网络设备1600也可以通过图20所示的设备来实现。此时，网络设备1600包括：至少一个处理器、通信总线以及至少一个通信接口。可选的，网络设备1600还可以包括存储器。
在具体实施例中，网络设备1600中的处理器用于通过通信接口接收第一报文；获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个。通过通信接口发送所述第二报文。该处理器的详细处理过程请参考上述实施例中的过程S410,S420,S430以及过程S325,S330,S335的详细描述，这里不再赘述。
网络设备1600中的通信接口用于网络设备1600通过网络系统接收和发送报文。具体的过程请参考上述实施例中S410,S440以及S325,S335的详细描述，这里不再赘述。
网络设备1600也可以通过图21所示的设备来实现。此时，网络设备1600包括主控板和一个或多个接口板，主控板与接口板通信连接。具体参见上述实施例中对网络设备2100的描述，在此不再赘述。
图24示出了上述实施例中所涉及的网络设备301的一种可能的结构示意图，网络设备1800可以实现上述实施例中网络设备301或网络设备401的功能。参阅图24，该网络设备1800包括：确定单元1801和处理单元1802。这些单元可以执行上述方法中网络设备301或网络设备401的相应功能。举例来说，
确定单元1801，用于确定报文的转发路径，所述转发路径包括多个网络设备。
处理单元1802，用于生成对应于所述转发路径的所述段列表，所述段列表包括依次排列的所述多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识。
可选的，网络设备1800还包括：发送单元1803。发送单元1803，用于向所述转 发路径的入口设备发送所述段列表。或者，所述处理单元1802，还用于将所述段列表封装至报文中；所述发送单元1803，用于发送所述报文。
网络设备1800也可以通过图20所示的设备来实现。此时，网络设备1800包括：至少一个处理器、通信总线以及至少一个通信接口。可选的，网络设备1800还可以包括存储器。
在具体实施例中，网络设备1800中的处理器用于确定报文的转发路径，所述转发路径包括多个网络设备；生成对应于所述转发路径的所述段列表，所述段列表包括依次排列的所述多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识。
可选的，网络设备1800中的处理器还用于通过通信接口发送所述段列表。
该处理器的详细处理过程请参考上述实施例中的过程S310,S315,S320以及S420的详细描述，这里不再赘述。
网络设备1800中的通信接口用于网络设备1900通过网络系统接收和发送信息。具体的过程请参考上述实施例中S320以及S420的详细描述，这里不再赘述。
参阅图25所示，图25示出本发明实施例提供的一种网络系统的可能的结构示意图。网络系统2200包括第一网络设备2201和第二网络设备2202。所述网络系统中的第一网络设备2201可以执行上述图18所示实施例中网络设备401的处理步骤S410,S420,S430,S440，或者上述图19所示实施例中网络设备302的处理步骤S325,S330,S335。所述网络系统中的第二网络设备2202可以执行上述图20所示实施例中网络设备402的处理步骤S450,S460,S470，或者网络设备303的处理步骤S340,S345,S350。
可选的，所述网络系统2200还包括第三网络设备2203。所述网络系统中的第一网络设备2203可以执行上述上述图19所示实施例中网络设备301的处理步骤S310,S315,S320。
相应的，所述网络系统中的第一网络设备2201可以为图23所示实施例中的网络设备1600，所述网络设备中的第二网络设备2202可以为图22所示实施例中的网络设备1400，所述网络设备中的第三网络设备2203可以为图24所示实施例中的网络设备1800。
具体的，所述第三网络设备，用于确定报文的转发路径，所述转发路径包括多个网络设备；生成对应于所述转发路径的所述段列表，所述段列表包括依次排列的所述多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识。
所述第二网络设备，用于接收第一报文；获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；在所述第一报文中添加 所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；发送所述第二报文。
可选的，当网络系统中包括所述第三网络设备时，所述第二网络设备获得所述段列表，是指所述第二网络设备接收所述第三网络设备发送的所述段列表。可选的，当网络系统中不包括所述第三网络设备时，所述第二网络设备获得所述段列表，是指所述第二网络设备生成所述段列表。
所述第一网络设备，用于接收所述第二报文，所述第二报文的第一报文头包括所述段列表，所述第二报文包括第一指针；根据所述第一指针的值确定所述第一标识在所述第一元素中的位置；将以所述第一标识为起始的至少一个标识拷贝至所述第二报文的第二报文头中，以生成第三报文；发送单元，用于发送所述第三报文。
本发明实施例还提供了一种非瞬态存储介质，用于储存前述实施例中所用的软件指令，其包括用于执行前述实施例所示的方法的程序，当其在计算机或网络设备上执行时，使得所示计算机或网络设备执行前述方法实施例中的方法。
本发明实施例还提供了一种包括计算机程序指令的计算机程序产品，当该计算机程序产品在计算机上运行时，使得网络节点执行前述方法实施例中的方法。
本发明实施例中提到的第一报文、第一网络设备、第一标识、第一指针和数量标志的“第一”只是用来做名字标识，并不代表顺序上的第一。该规则同样适用于“第二”、“第三”和“第四”等。然而，本发明实施例中提到的第一个标识中的“第一个”代表顺序上的第一。该规则同样适用于“第N个”。
本发明实施例中认为“A和/或B”包含单独A，单独B，和A+B。
需说明的是，以上描述的任意装置实施例都仅仅是示意性的，其中所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部模块来实现本实施例方案的目的。另外，本发明提供的网络设备或主机的实施例附图中，模块之间的连接关系表示它们之间具有通信连接，具体可以实现为一条或多条通信总线或信号线。本领域普通技术人员在不付出创造性劳动的情况下，即可以理解并实施。
本发明实施例公开内容所描述的方法或者算法的步骤可以硬件的方式来实现，也可以是由处理器执行软件指令的方式来实现。软件指令可以由相应的软件模块组成，软件模块可以被存放于随机存取存储器(random access memory，RAM)、闪存、只读存储器(read-only memory，ROM)、可擦除可编程只读存储器(erasable programmable ROM，EPROM)、电可擦可编程只读存储器(electrically EPROM，EEPROM)、硬盘、移动硬盘、光盘或者本领域熟知的任何其它形式的存储介质中。存储介质耦合至处理器，从而使处理器能够从该存储介质读取信息。当然，存储介质也可以是处理器的组成部分。
以上所述的具体实施方式，对本发明的目的、技术方案和有益效果进行了进一步详细说明，所应理解的是，以上所述仅为本发明的具体实施方式而已，并不用于限定本发明的保护范围，凡在本发明的技术方案的基础之上，所做的任何修改、替 换、改进等，均应包括在本发明的保护范围之内。

Claims (57)

  1. 一种转发报文的方法，其特征在于，所述方法包括：
    接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针；
    根据所述第一指针的值确定第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；
    将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文；
    发送所述第二报文。
  2. 根据权利要求1所述的方法，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于一个网络设备或一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述多个段标识中的每个段标识的第一部分为前缀部分，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  3. 根据权利要求2所述的方法，其特征在于，所述第二报文头包括目的地址字段，所述目的地址字段包括第一部分和第二部分，所述目的地址的第一部分包括所述前缀部分；
    所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中，包括：
    将以所述第一标识为起始的至少一个标识拷贝至所述目的地址字段的第二部分中。
  4. 根据权利要求2或3所述的方法，其特征在于，所述段列表不包括所述前缀部分。
  5. 根据权利要求2-4任一项所述的方法，其特征在于，所述多个标识的长度相同，所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之前，所述方法还包括：
    根据所述多个标识的长度和所述前缀部分的长度确定所述至少一个标识的数量。
  6. 根据权利要求1所述的方法，其特征在于，所述第一报文包括目的地址字段，所述目的地址字段包括第二标识，所述第二标识是所述多个标识中的一个；
    所述根据所述第一指针的值确定所述第一标识在所述第一元素中的位置之前，所述方法还包括：
    根据所述第二标识中的切换标志，确定所述段列表中包括与所述第二标识的类型不同的标识；
    所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中，包括：
    将所述至少一个标识拷贝至所述第二报文头中以形成转发标识栈，所述至少一 个标识与所述第二标识的类型不同。
  7. 根据权利要求6所述的方法，其特征在于，所述第一报文包括数量标志；
    所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之前，所述方法还包括：
    根据所述数量标志的值确定所述至少一个标识的数量。
  8. 根据权利要求6或7所述的方法，其特征在于，所述根据所述第一指针的值确定所述第一标识在所述第一元素中的位置，包括：
    确定所述目的地址字段中多余标识的数量，所述多余标识的类型与所述第二标识不同；
    根据所述多余标识的数量校正所述第一指针的值；
    根据校正后的所述第一指针的值确定所述第一标识在所述第一元素中位置。
  9. 根据权利要求6-8任一项所述的方法，其特征在于，所述至少一个标识为多协议标签交换MPLS标签或互联网协议版本4IPv4地址。
  10. 根据权利要求1-9任一项所述的方法，其特征在于，所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之后，所述方法还包括：
    修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第三标识在所述第一元素中的位置，所述第三标识不属于所述至少一个标识。
  11. 根据权利要求1-9任一项所述的方法，其特征在于，所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之后，所述方法还包括：
    修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第三标识在第二元素中的位置，所述第三标识不属于所述至少一个标识，所述第二元素与所述第一元素不同。
  12. 根据权利要求1-11任一项所述的方法，其特征在于，所述第一报文还包括第二指针，所述根据所述第一指针的值确定所述第一标识在所述第一元素中的位置之前，所述方法还包括：
    根据所述第二指针的值确定所述第一元素在所述第一报文中的位置。
  13. 一种转发报文的方法，其特征在于，所述方法包括：
    接收第一报文；
    获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；
    在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；
    发送所述第二报文。
  14. 根据权利要求13所述的方法，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个段标识的前缀部分相同，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  15. 根据权利要求14所述的方法，其特征在于，所述第一报文的报文头包括目的地址字段，所述目的地址字段包括第一部分和第二部分；
    所述在所述第一报文中添加所述段列表以生成所述第二报文，包括：
    在所述目的地址字段的第一部分中添加所述前缀部分；
    在所述目的地址字段的第二部分中添加所述多个标识中的一个或多个标识。
  16. 根据权利要求14-15任一项所述的方法，其特征在于，所述段列表中不包括所述前缀部分。
  17. 根据权利要求13所述的方法，其特征在于，所述多个标识中的至少一个标识为多协议标签交换MPLS标签或互联网协议版本4IPv4地址。
  18. 根据权利要求17所述的方法，其特征在于，所述第二报文包括数量标志，所述数量标志的值用于指示所述至少一个标识的数量。
  19. 根据权利要求13-18任一项所述的方法，其特征在于，所述第一指针位于所述第二报文的报文头中。
  20. 根据权利要求13-19任一项所述的方法，其特征在于，所述第二报文还包括第二指针，所述第二指针的值用于指示所述第一元素在所述段列表中的位置。
  21. 一种生成用于转发报文的段列表的方法，其特征在于，所述方法包括：
    确定报文的转发路径，所述转发路径包括多个网络设备；
    生成对应于所述转发路径的所述段列表，所述段列表包括依次排列的所述多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识。
  22. 根据权利要求21所述的方法，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个标识的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  23. 根据权利要求22所述的方法，其特征在于，所述多个段标识中的段标识还包括第三部分，所述第三部分为填充部分，所述多个段标识的填充部分相同，所述多个标识中的标识不包括所述填充部分。
  24. 根据权利要求22或23所述的方法，其特征在于，所述多个段标识包括第一段标识，所述段列表不包括所述第一段标识的前缀部分。
  25. 根据权利要求24所述的方法，其特征在于，所述多个段标识还包括第二段标识，所述第一段标识的前缀部分和所述第二段标识的前缀部分不同，所述段列表 包括所述第二段标识的前缀部分。
  26. 根据权利要求21-25任一项所述的方法，其特征在于，所述多个标识中的至少一个标识为段标识、多协议标签交换MPLS标签或互联网协议版本4IPv4地址。
  27. 根据权利要求21-26任一项所述的方法，其特征在于，所述生成对应于所述转发路径的所述段列表之后，所述方法还包括：
    向所述转发路径的入口设备发送所述段列表；或者，
    将所述段列表封装至报文中，并发送所述报文。
  28. 一种网络设备，其特征在于，所述网络设备包括：
    接收单元，用于接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针；
    处理单元，用于根据所述第一指针的值确定第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文；
    发送单元，用于发送所述第二报文。
  29. 根据权利要求28所述的网络设备，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于一个网络设备或一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述多个段标识中的每个段标识的第一部分为前缀部分，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  30. 根据权利要求29所述的网络设备，其特征在于，所述第二报文头包括目的地址字段，所述目的地址字段包括第一部分和第二部分，所述目的地址的第一部分包括所述前缀部分；
    所述处理单元，还用于将以所述第一标识为起始的至少一个标识拷贝至所述目的地址字段的第二部分中。
  31. 根据权利要求29或30所述的网络设备，其特征在于，所述多个标识的长度相同；
    所述处理单元，还用于根据所述多个标识的长度和所述前缀部分的长度确定所述至少一个标识的数量。
  32. 根据权利要求28所述的网络设备，其特征在于，所述第一报文包括目的地址字段，所述目的地址字段包括第二标识，所述第二标识是所述多个标识中的一个；
    所述处理单元，还用于根据所述第二标识中的切换标志，确定所述段列表中包括与所述第二标识的类型不同的标识；将所述至少一个标识拷贝至所述第二报文头中以形成转发标识栈，所述至少一个标识与所述第二标识的类型不同。
  33. 根据权利要求32所述的网络设备，其特征在于，所述第一报文包括数量标志；
    所述处理单元，还用于根据所述数量标志的值确定所述至少一个标识的数量。
  34. 根据权利要求32或33所述的网络设备，其特征在于，
    所述处理单元，还用于确定所述目的地址字段中多余标识的数量，所述多余标识的类型与所述第二标识不同；根据所述多余标识的数量校正所述第一指针的值；根据校正后的所述第一指针的值确定所述第一标识在所述第一元素中位置。
  35. 根据权利要求32-34任一项所述的网络设备，其特征在于，所述至少一个标识包括多协议标签交换MPLS标签或互联网协议版本4IPv4地址。
  36. 根据权利要求28-35任一项所述的网络设备，其特征在于，
    所述处理单元，还用于修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第三标识在所述第一元素中的位置，所述第三标识不属于所述至少一个标识。
  37. 根据权利要求28-35任一项所述的网络设备，其特征在于，
    所述处理单元，还用于修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第三标识在第二元素中的位置，所述第三标识不属于所述至少一个标识，所述第二元素与所述第一元素不同。
  38. 一种网络设备，其特征在于，所述网络设备包括：
    接收单元，用于接收第一报文；
    处理单元，用于获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的标识对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述第一元素中的位置，所述第一标识为所述至少两个标识中的一个；
    发送单元，用于发送所述第二报文。
  39. 根据权利要求38所述的网络设备，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个段标识的前缀部分相同，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  40. 根据权利要求39所述的网络设备，其特征在于，所述第一报文的报文头包括目的地址字段，所述目的地址字段包括第一部分和第二部分；
    所述处理单元，还用于在所述目的地址字段的第一部分中添加所述前缀部分；在所述目的地址字段的第二部分中添加所述多个标识中的一个或多个标识。
  41. 根据权利要求38所述的网络设备，其特征在于，所述多个标识中的至少一个标识为多协议标签交换MPLS标签或互联网协议版本4IPv4地址。
  42. 一种网络设备，其特征在于，所述网络设备包括：
    确定单元，用于确定报文的转发路径，所述转发路径包括多个网络设备；
    处理单元，用于生成对应于所述转发路径的段列表，所述段列表包括依次排列的所述多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识。
  43. 根据权利要求42所述的网络设备，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个标识的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  44. 根据权利要求43所述的网络设备，其特征在于，所述多个段标识中的段标识还包括第三部分，所述第三部分为填充部分，所述多个段标识的填充部分相同，所述多个标识中的标识不包括所述填充部分。
  45. 根据权利要求42-44任一项所述的网络设备，其特征在于，所述多个标识中的至少一个标识为段标识、多协议标签交换MPLS标签或互联网协议版本4IPv4地址。
  46. 根据权利要求42-45任一项所述的网络设备，其特征在于，所述网络设备还包括发送单元，
    所述发送单元，用于向所述转发路径的入口设备发送所述段列表；或者，
    所述处理单元，还用于将所述段列表封装至报文中，
    所述发送单元，用于发送所述报文。
  47. 一种转发报文的方法，其特征在于，所述方法包括：
    接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针；
    根据所述第一指针的值确定第一标识在所述段列表中的位置，所述第一标识为所述至少两个标识中的一个；
    将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文；
    发送所述第二报文。
  48. 根据权利要求47所述的方法，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于一个网络设备或一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述多个段标识中的每个段标识的第一部分为前缀部分，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  49. 根据权利要求47所述的方法，其特征在于，所述第一报文包括目的地址字段，所述目的地址字段包括第二标识，所述第二标识是所述多个标识中的一个；
    所述根据所述第一指针的值确定所述第一标识在所述段列表中的位置之前，所述方法还包括：
    根据所述第二标识中的切换标志，确定所述段列表中包括与所述第二标识的类型不同的标识；
    所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中，包括：
    将所述至少一个标识拷贝至所述第二报文头中以形成转发标识栈，所述至少一个标识与所述第二标识的类型不同。
  50. 根据权利要求47-49任一项所述的方法，其特征在于，所述将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的所述第二报文头中之后，所述方法还包括：
    修改所述第一指针的值，以使得修改后的所述第一指针的值用于指示第三标识在所述段列表中的位置，所述第三标识不属于所述至少一个标识。
  51. 一种转发报文的方法，其特征在于，所述方法包括：
    接收第一报文；
    获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；
    在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述段列表中的位置，所述第一标识为所述至少两个标识中的一个；
    发送所述第二报文。
  52. 根据权利要求51所述的方法，其特征在于，所述多个标识一一映射到多个段标识，所述多个段标识中的每个段标识分别对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述多个段标识中的每个段标识包括第一部分和第二部分，所述每个段标识的第一部分是前缀部分，所述多个段标识的前缀部分相同，所述多个标识中的每个标识分别包括所述每个标识所映射到的段标识的第二部分。
  53. 根据权利要求51所述的方法，其特征在于，所述多个标识中的至少一个标识为多协议标签交换MPLS标签或互联网协议版本4IPv4地址。
  54. 一种网络设备，其特征在于，所述网络设备包括：
    接收单元，用于接收第一报文，所述第一报文的第一报文头包括用于转发所述第一报文的段列表，所述段列表包括依次排列的多个标识，所述多个标识中的每个标识分别对应于一个网络设备或一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识，所述第一报文包括第一指针；
    处理单元，用于根据所述第一指针的值确定第一标识在所述段列表中的位置，所述第一标识为所述至少两个标识中的一个；将以所述第一标识为起始的至少一个标识拷贝至所述第一报文的第二报文头中，以生成第二报文；
    发送单元，用于发送所述第二报文。
  55. 一种网络设备，其特征在于，所述网络设备包括：
    接收单元，用于接收第一报文；
    处理单元，用于获得段列表，所述段列表对应于所述第一报文的转发路径，所述转发路径包括多个网络设备，所述段列表包括依次排列的多个标识，所述多个标识中的标识对应于所述多个网络设备中的一个网络设备或所述转发路径中的一个链路，所述段列表包括长度为128比特的第一元素，所述第一元素包括所述多个标识中的相邻的至少两个标识；在所述第一报文中添加所述段列表以生成第二报文，所述第二报文包括第一指针，所述第一指针的值用于指示第一标识在所述段列表中的位置，所述第一标识为所述至少两个标识中的一个；
    发送单元，用于发送所述第二报文。
  56. 一种网络系统，其特征在于，所述网络系统包括第一网络设备和第二网络设备，其中，所述第一网络设备是如权利要求28-37任一项所述的网络设备，所述第二网络设备是如权利要求38-41任一项所述的网络设备；或者，
    所述第一网络设备是如权利要求54所述的网络设备，所述第二网络设备是如权利要求55所述的网络设备。
  57. 根据权利要求56所述的网络系统，其特征在于，所述网络系统还包括第三网络设备，所述第三网络设备是如权利要求42-46任一项所述的网络设备。
PCT/CN2020/088788 2019-08-31 2020-05-06 一种在sr网络中转发报文的方法、设备和系统 Ceased WO2021036328A1 (zh)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113207192A (zh) * 2021-03-29 2021-08-03 新华三信息安全技术有限公司 一种报文转发方法及装置
WO2023208056A1 (zh) * 2022-04-29 2023-11-02 华为技术有限公司 处理报文的方法、装置以及系统
US20230370375A1 (en) * 2020-09-24 2023-11-16 Zte Corporation Data processing method and system, encapsulation node, and de-encapsulation node
EP4510522A4 (en) * 2022-05-11 2025-06-25 Huawei Technologies Co., Ltd. PACKET PROCESSING METHOD, APPARATUS, SYSTEM AND COMPUTER-READABLE STORAGE MEDIUM

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113438160B (zh) * 2020-03-23 2024-05-31 中兴通讯股份有限公司 路由方法、路由装置及计算机可读存储介质
US11445048B2 (en) * 2020-08-11 2022-09-13 Cisco Technology, Inc. Systems and methods for compressing a SID list
CN114666259A (zh) * 2020-12-22 2022-06-24 华为技术有限公司 报文传输的方法、装置、设备、存储介质及系统
CN114900756B (zh) * 2022-05-10 2024-04-09 中国联合网络通信集团有限公司 数据传输方法及装置、计算机可读存储介质

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170250908A1 (en) * 2016-02-29 2017-08-31 Cisco Technology, Inc. System and Method for Dataplane-Signaled Packet Capture in a Segment Routing Environment
US20180034727A1 (en) * 2016-07-28 2018-02-01 Cisco Technology, Inc. Enhanced error signaling and error handling in a network environment with segment routing
WO2019005949A1 (en) * 2017-06-27 2019-01-03 Cisco Technology, Inc. GATEWAY OF SEGMENT ROUTING
CN109688057A (zh) * 2018-12-13 2019-04-26 Ut斯达康通讯有限公司 基于ipv6的段路由网络的报文转发方法及装置
CN109981457A (zh) * 2017-12-27 2019-07-05 华为技术有限公司 一种报文处理的方法、网络节点和系统

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9537769B2 (en) * 2013-03-15 2017-01-03 Cisco Technology, Inc. Opportunistic compression of routing segment identifier stacks
CN106411738A (zh) * 2015-07-30 2017-02-15 中兴通讯股份有限公司 Ipv6报文封装的处理方法和装置
JP6967521B2 (ja) * 2016-02-15 2021-11-17 テレフオンアクチーボラゲット エルエム エリクソン（パブル） Ｏｓｐｆを利用して最大ノードおよび／またはリンクセグメント識別子深度を明らかにするための技法
CN109218189B (zh) * 2017-07-03 2022-04-29 中兴通讯股份有限公司 跨域的路径的标识信息的确定方法、装置及存储介质
US10404600B2 (en) * 2017-09-12 2019-09-03 Google Llc Mechanism and apparatus for path protection when using compressed segment routing label stacks
CN108429685B (zh) * 2018-04-28 2020-08-04 电子科技大学 一种基于分段路由技术的服务功能链寻路方法
US11025545B2 (en) * 2019-06-06 2021-06-01 Cisco Technology, Inc. Conditional composition of serverless network functions using segment routing
CN112583745A (zh) * 2019-09-27 2021-03-30 华为技术有限公司 一种在sr网络中转发报文的方法、设备和系统

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170250908A1 (en) * 2016-02-29 2017-08-31 Cisco Technology, Inc. System and Method for Dataplane-Signaled Packet Capture in a Segment Routing Environment
US20180034727A1 (en) * 2016-07-28 2018-02-01 Cisco Technology, Inc. Enhanced error signaling and error handling in a network environment with segment routing
WO2019005949A1 (en) * 2017-06-27 2019-01-03 Cisco Technology, Inc. GATEWAY OF SEGMENT ROUTING
CN109981457A (zh) * 2017-12-27 2019-07-05 华为技术有限公司 一种报文处理的方法、网络节点和系统
CN109688057A (zh) * 2018-12-13 2019-04-26 Ut斯达康通讯有限公司 基于ipv6的段路由网络的报文转发方法及装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
C. FILSFILS, ED. D. DUKES, ED. CISCO SYSTEMS, INC. S. PREVIDI HUAWEI J. LEDDY INDIVIDUAL S. MATSUSHIMA SOFTBANK D. VOYER BELL CANA: "IPv6 Segment Routing Header (SRH); draft-ietf-6man-segment-routing-header-21.txt", IPV6 SEGMENT ROUTING HEADER (SRH); DRAFT-IETF-6MAN-SEGMENT-ROUTING-HEADER-21.TXT; INTERNET-DRAFT: NETWORK WORKING GROUP, INTERNET ENGINEERING TASK FORCE, IETF; STANDARDWORKINGDRAFT, INTERNET SOCIETY (ISOC) 4, RUE DES FALAISES CH- 1205 GENEVA, SWITZER, no. 21, 13 June 2019 (2019-06-13), Internet Society (ISOC) 4, rue des Falaises CH- 1205 Geneva, Switzerland, pages 1 - 32, XP015133345 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230370375A1 (en) * 2020-09-24 2023-11-16 Zte Corporation Data processing method and system, encapsulation node, and de-encapsulation node
US12381820B2 (en) * 2020-09-24 2025-08-05 Zte Corporation Data processing method and system, encapsulation node, and de-encapsulation node
CN113207192A (zh) * 2021-03-29 2021-08-03 新华三信息安全技术有限公司 一种报文转发方法及装置
WO2023208056A1 (zh) * 2022-04-29 2023-11-02 华为技术有限公司 处理报文的方法、装置以及系统
EP4510522A4 (en) * 2022-05-11 2025-06-25 Huawei Technologies Co., Ltd. PACKET PROCESSING METHOD, APPARATUS, SYSTEM AND COMPUTER-READABLE STORAGE MEDIUM

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