JPH1132064A - Communication protocol processing device - Google Patents

Abstract

(57) [Problem] To perform IP packet communication between IEEE 1394 nodes, a new IP processing means and ARP processing means must be created. SOLUTION: A header conversion unit 202 converts an Ethernet frame header and an IEEE 1394 packet header into each other, so that a communication protocol processing device can be implemented by using an IP processing unit 200 or an ARP processing unit 201 already implemented in Ethernet. This makes it possible to construct IP packets easily between IEEE 1394 nodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a communication protocol processing device mounted on a node connected to a bus conforming to the standard.

[0002]

2. Description of the Related Art Conventionally, IEEE1394 is known as a digital interface for transferring digital video data and audio data. In IEEE1394, there is a concept of a node ID as identification information for specifying a plurality of connected nodes. The node ID has 16 bits, and a 10-bit bus ID is included therein.
And a 6-bit physical ID. As a result,
It is possible to connect 63 devices on one bus, and it is possible to add up to 1023 such buses. Further, in IEEE1394, all connected nodes have a virtual 48-bit address space. A node is identified by a 16-bit node ID, and a 48-bit address offset is added to a total of 64 bits.
By specifying the destination address of the bit, communication can be performed between nodes.

FIG. 3 shows a packet format defined by IEEE 1394. 3, reference numeral 300 denotes a destination node ID; 301, additional information indicating a packet type;
02 is a source node ID, 303 is a destination offset address, 304 is a write data length, 305 is a CRC (cyclic redundancy check) for a header, 306 is write data, and 307 is a CR for write data.
C.

The write data 306 transmitted in such a packet format is transmitted to the node specified by the transmission destination node ID 300 among a plurality of nodes connected to the IEEE 1394 in an address space mounted on the node. The address specified by the destination offset address 303 is written to the memory space of the byte indicated by the write data length 304 at the head, and as a result, data communication between nodes can be realized.

On the other hand, in recent years, Internet Protocol (IP) has been frequently used as a protocol for data communication. In the IP packet communication, as shown in FIG.
Although it is specified that communication is performed in units of an IP packet 400 having a P header 401 and IP data 402, what is actually transmitted on a medium is not the IP packet 400 but a medium-dependent format. Ethernet (or IEEE)
802.3), communication is performed in units called frames 403 shown in FIG. The frame 403 is composed of a 48-bit destination MAC address 406 and a source MAC address 4
07 and frame header 4 specifying frame type 408
04 and frame data 405, and the IP packet 400 is included in the frame data 405.

FIG. 2 shows a block diagram of the IP packet communication. In FIG. 2, reference numeral 200 denotes IP processing means, 201 denotes A
RP (Address Resolution Pro)
tocol) processing means, 202 is a data link means, 2
03 is an Ethernet transmitting / receiving means, and 204 is an Ethernet transmission medium. The IP processing means 200 adds an IP header 401 designating a 32-bit destination IP address to the IP data 402 to be communicated at the time of data transmission, generates an IP packet 400, and outputs it to the data link means 202. When data is received, the IP header 401 of the IP packet 400 input from the data link unit 202 is removed to extract IP data 402. The ARP processing means 201 generates an ARP request packet specifying a specific IP address at the time of the ARP request, and outputs the generated ARP request packet to the data link means 202 so as to perform broadcast transmission. When the ARP processing means 201 confirms its own IP address in the ARP request packet upon receiving the ARP request packet, the ARP processing means 201 generates an ARP response packet designating its own MAC address and sends it to the data link means 202 so as to transmit it to the source of the ARP request packet. At the same time as the output, the ARP request packet transmission source IP address / MAC address pair table is held. Further, the ARP processing means 201
When a response packet is received, the source IP address and MAC address are extracted from the ARP response packet, and an IP address / MAC address pair table is held.

At the time of transmission, the data link means 202 reads the destination I from the IP address / MAC address pair table.
A MAC address corresponding to the P address is specified, a frame header is added to generate a frame, and the frame is output to the Ethernet transmitting / receiving means 203. Further, data link means 202
At the time of reception, for a frame corresponding to its own MAC address, the in-frame data is output to processing means corresponding to an IP packet or an ARP packet from the frame type of the frame header. Ethernet transmission / reception means 203
Performs transmission / reception processing on the Ethernet transmission medium 204.

[0008]

However, when IP packet communication is performed by IEEE1394 which requires a 64-bit transmission destination address, an IP processing unit or an ARP processing unit which is mounted on a 48-bit Ethernet MAC address is targeted. It is impossible to use as it is,
All had to be newly developed.

The present invention has been made in view of such a problem, and has been developed by the IE.
It is an object of the present invention to provide a communication protocol processing device that can directly use an IP processing unit and an ARP processing unit implemented in Ethernet in EE1394.

[0010]

In order to solve the above-mentioned problems, a communication protocol processing apparatus according to the present invention uses an IEEE13
It is provided with a header conversion means for performing a header conversion for converting the 94 packet header and the Ethernet frame header into each other.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a communication protocol processing device mounted on a node connected to an IEEE 1394-based bus, the communication protocol processing device comprising an Ethernet or IEEE 8
It has frame processing means for processing a frame conforming to H.22.3, and header conversion means for converting a frame header and an IEEE 1394 packet header. This allows
The IP processing unit and the ARP processing unit mounted on the Ethernet can be used as they are.

Hereinafter, a communication protocol processing device according to an embodiment of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram of a communication protocol processing device according to an embodiment of the present invention. In FIG. 1, reference numeral 200 denotes IP processing means, 201 denotes ARP processing means,
202 is a data link unit, 100 is a header conversion unit, 101 is an IEEE 1394 packet transmitting / receiving unit (in the figure, it is simply an IEEE 1394 transmitting / receiving unit), and 102 is an IEEE 1394 transmission medium as a bus compliant with IEEE 1394. The frame processing means includes an IP processing means 200, an ARP processing means 201
And data link means 202.

The operation of the communication protocol processing device configured as described above will be described with reference to FIG. However, the same operations as those in the conventional example are denoted by the same reference numerals as in FIG. 2 and the description is omitted. In FIG. 1, the header conversion means 100 converts the destination MAC address 406 and the source MAC address 407, which are the frame headers of the data link means 202, into the destination node ID 300, the destination offset address 303 and the source Converted to node ID 302 and converted to IEEE 139
Four packets are generated and output to the IEEE 1394 packet transmitting / receiving means 101. In addition, when receiving, IEEE13
The destination node ID 300, the destination offset address 303, and the source node ID 302 of the 94 packet are respectively set to the destination MAC address 406 and the source MAC.
The data is converted into an address 407 to generate an Ethernet frame and output to the data link unit 202. IEEE13
The 94 packet transmission / reception means 101 performs transmission / reception processing on the IEEE 1394 transmission medium 102. The ARP processing means 201 determines the lower 3 bits of the 16-bit own node ID and the 48-bit own offset address as the own MAC address.
Set 2 bits.

Hereinafter, the operation of the header conversion means 100 will be described in detail. (1) At the time of packet transmission The following conversion is performed on the header of the Ethernet frame input from the data link means 202. (1-1) Destination MAC Address As shown in FIG. 5, the upper 16 bits of the 48-bit destination MAC address are the destination node ID 300. The lower 32 bits of the 48-bit destination MAC address are set as the lower 32 bits of the destination offset address 303, and the upper 16 bits of the destination offset address 303 are filled with the most significant bit of the lower 32 bits of the destination MAC address. . That is, as shown in FIG. 5, the upper 17 bits of the destination offset address 303 are filled with the same value X. (1-2) Source MAC Address As shown in FIG. 5, the upper 16 bits of the 48-bit source MAC address are the source node ID 302.

The above two MAC addresses are converted, an IEEE 1394 packet is generated from the Ethernet frame, and output to the IEEE 1394 packet transmitting / receiving means 101. (2) When receiving an IP packet The following conversion is performed on the header of the IEEE 1394 packet input from the IEEE 1394 packet receiving unit 101. (2-1) Destination Node ID As shown in FIG.
The upper 16 bits of the 8-bit destination MAC address. (2-2) Destination Offset Address As shown in FIG. 6, the lower 32 bits of the 48-bit destination offset address are the lower 32 bits of the 48-bit destination MAC address. (2-3) Source Node ID As shown in FIG.
The upper 16 bits of the source MAC address of 8 bits.

The above three header information are converted and the IEEE
An Ethernet frame is generated from the E1394 packet and output to the data link unit 202. As described above, the header conversion means 100 mutually converts the IEEE 1394 packet header and the Ethernet frame header. As a result, the data format exchanged between the header conversion unit 100 and the data link unit 202 becomes the same as that of the Ethernet frame, and the data link unit 202 can use the same unit as the unit implemented in the conventional Ethernet. . Also, the data link means 202
As the IP processing means 200 and the ARP processing means 201 located at higher levels, the same means as the means implemented in the conventional Ethernet can be used.

As described above, according to the present embodiment, the IE
By converting the EE1394 packet header and the Ethernet frame header into each other, the data link means and the IP processing means implemented in the existing Ethernet, and the IEEE 1394 node by the communication protocol processing device using the same means as the ARP processing means. Can perform IP packet communication.

It is needless to say that the communication protocol processing device according to the present embodiment can be used in a digital AV device, a computer and its peripheral devices, or a communication device. In addition, a communication system having at least two or more such devices may be provided.

[0019]

As described above, the present invention uses the data link means, the IP processing means, and the ARP processing means which are mounted on the existing Ethernet, and easily adds the IEEE1394 simply by adding a new header conversion means. I between nodes
A communication protocol processing device for performing P packet communication can be constructed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a communication protocol processing device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional communication protocol processing device.

FIG. 3 is a conceptual diagram showing an IEEE 1394 packet configuration;

FIG. 4 is a conceptual diagram showing a configuration of an IP packet and a frame.

FIG. 5 is a conceptual diagram showing conversion from a frame header to an IEEE 1394 packet header when transmitting an IP packet according to the present invention;

FIG. 6 shows IEEE when receiving an IP packet according to the present invention.
Conceptual diagram showing conversion from 1394 packet header to frame header

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 header conversion means 101 IEEE 1394 transmission / reception means 102 IEEE 1394 transmission medium 200 IP processing means 201 ARP processing means 202 data link means

Claims (11)

[Claims] 1. A communication protocol processing device mounted on a node connected to an IEEE 1394 compliant bus, the frame processing unit processing a frame compliant with Ethernet or IEEE 802.3, a frame header and an IEEE 1394 packet header. A communication protocol processing device, comprising: 2. The communication protocol according to claim 1, wherein the header conversion means converts the destination MAC address in the frame header, the destination IEEE 1394 node ID and the destination IEEE 1394 offset address in the IEEE 1394 packet header. Processing equipment. 3. The header conversion means converts the 48-bit transmission destination MAC address in the frame header to the IEEE139
The packet is converted into a 16-bit IEEE 1394 destination node ID in a 4-packet header and a 32-bit lower address, and the most significant bit of the lower address is bit-extended and converted into a 48-bit destination IEEE 1394 offset address in the IEEE 1394 packet header. 3. The communication protocol processing device according to claim 2, wherein 4. The header converting means converts the 48-bit source MAC address in the frame header to IEEE 139
3. The communication protocol processing apparatus according to claim 2, wherein the data is converted into a 16-bit IEEE 1394 transmission source node ID in four packet headers. 5. The header conversion means converts from the lower 32 bits of the 16-bit destination node ID and the 48-bit IEEE 1394 destination offset address in the IEEE 1394 packet header to the 48-bit destination MAC address in the frame header. The communication protocol processing device according to claim 2, wherein: 6. The header conversion means extends the 16-bit source node ID in the IEEE 1394 packet header by bits, and expands the 48-bit source MAC in the frame header.
3. The communication protocol processing device according to claim 2, wherein the communication protocol processing device converts the address into an address. 7. The frame processing means uses the 16-bit IEEE 1394 node ID for the own node and the lower 32 bits of the 48-bit IEEE 1394 offset address mounted on the own node as a 48-bit MAC address for the own node. Claim 1
The communication protocol processing device according to the above. 8. A digital AV device comprising the communication protocol device according to claim 1. 9. A computer comprising the communication protocol device according to claim 1 or 2 and a peripheral device thereof. 10. A communication device comprising the communication protocol device according to claim 1. 11. A communication system having at least two devices according to claim 8.