JPH05260077A - Message processing system for connectionless communication - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to realize high-speed cell routing. [Structure] A called subscriber address stored in an information field of a BOM cell is latched in a DA latch circuit 13, and D
By referring to the A-RDA conversion table TB, the destination subscriber address DA is converted into address information RDA having a smaller number of bits. Then, the selector 15 adds the above-mentioned address information R to the header of the BOM cell stored in the buffer 14.
The DA is written as the information designating the called subscriber. When routing a cell in the message handler, the address information RDA written in the header of this cell
Is processed by hardware or the like to determine the outgoing route of the cell.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a message processing method in connectionless communication, and more particularly to a message processing method for speeding up routing processing in switching nodes.

[0002]

2. Description of the Related Art An ATM switching network has been proposed as a network for integrally realizing voice, image and high-speed data communication. Proposals have been made to enable transfer of connectionless information such as LAN in such a connection type switching network.

For example, there is one in which each ATM switch of the ATM switching network is provided with a message handler for transferring a connectionless cell. The message handler analyzes the called subscriber address information added to the head cell (BOM cell) of the connectionless type cell and performs the cell routing, stores the address information, and stores it in the subsequent COM cells. , EOM cells are routed to the same route.

[0004]

By the way, in a network for performing high-speed data communication such as an ATM switching network,
It is necessary to minimize the processing delay in the network.

However, in the processing such as the analysis of the called subscriber address information and the cell routing in the above-mentioned message handler, it takes a lot of time because the amount of the called subscriber address information is large, and a processing delay occurs. There was a problem. In addition, it is necessary to provide a memory for storing the above-mentioned called subscriber address information and the like in the message handler, but a large memory capacity is required due to the large amount of information such as called subscriber address information. There were also problems.

An object of the present invention is to realize high-speed routing by reducing address information required for cell routing.

[0007]

FIG. 1 is a block diagram showing the principle of the present invention. According to the message processing method in the connectionless communication of the present invention, the address information of the called subscriber added to the connectionless cell in the subscriber line exchange can be specified with a smaller amount of information than the address information. There is provided an address converting means 1 for converting the cell into an address and a routing means 2 for routing a corresponding cell to a predetermined output route based on the address information.

[0008]

According to the present invention, in the subscriber line exchange, the called subscriber address information added to the received cell can be identified as the called subscriber corresponding to the called subscriber address information.
The information is converted into address information having a smaller amount of information, and the cell is routed to a predetermined output route according to the address information.

By degenerating the called subscriber address information added to the cell in this manner, the cell can be routed by hardware or the like that does not depend on the processor of the exchange. And the processing delay in the exchange can be reduced. Further, since the amount of address information to be stored is reduced, the memory capacity can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram of an ATM switching network of an embodiment which provides both connection communication and connectionless communication.

Each of the exchanges 11a to 11c is provided with message handlers 12a to 12c for analyzing the called subscriber address added to the connectionless cell and routing the cell based on the analysis result.

A subscriber line exchange 1 accommodating a plurality of subscribers
A DA-RDA conversion circuit for converting the incoming subscriber address DA into address information (RDA) having a smaller amount of information is provided in 1c.

FIG. 3 is a diagram for explaining the configuration of the DA-RDA conversion circuit and the operation of the circuit. As shown in the figure, D
The A-RDA conversion circuit is a DA latch circuit 13 that latches the called subscriber address DA stored in the BOM cell.
And a DA-RDA conversion table TB showing the correspondence between the destination subscriber address DA and the address information RDA degenerated from the DA, and the buffer 14 for temporarily storing the received cell.
And a selector 15 for adding the degenerated address information RDA to the header portion of the cell and outputting it.

The destination subscriber address is address data having a data length of 48 bits stored in the information field of the BOM cell. For example, from the subscriber's area code, local code, individual telephone number, etc. Is becoming

By the way, the subscriber line switch installed in the lower layer of the ATM switching network does not need all the called subscriber address information added to the cell when the cell is routed. For example, in the case of routing a cell received by a subscriber line exchange accommodating a subscriber terminal, an individual telephone number among the area code, local area code, individual telephone number, etc. given as a destination subscriber address. Should be known.

Therefore, in the present embodiment, the correspondence between the subscriber address DA and the address information RDA for identifying each subscriber accommodated in the exchange is shown in the message handler of the subscriber line exchange. A DA-RDA conversion table TB is provided, and by using the conversion table TB, the incoming subscriber address DA of the received cell is converted into address information RDA having a smaller number of bits, and the address information RD is obtained.
The cell is routed by A.

FIG. 4 shows the DA-RDA conversion table T.
It is a figure which shows an example of B. In this conversion table TB,
A subscriber telephone number (area code, local area code, individual telephone number, etc.) consisting of 48-bit data at the maximum is stored as the destination subscriber address DA, and an individual telephone number corresponding to the destination subscriber address DA is stored. Number data 1 to n designating a subscriber is stored as address information RDA.

Therefore, this DA-RDA conversion table T
By referring to B, the called subscriber address DA added to the cell can be determined by the address information RDA having a smaller number of bits.
Can be converted to.

Next, the operation of the DA-RDA conversion circuit will be described with reference to the circuit configuration diagram of FIG. 3 and the flowchart of FIG. First, the called subscriber address DA stored in the header portion of the BOM cell is latched in the latch circuit 13 (FIG. 4, S1). Next, referring to the DA-RDA conversion table TB, the called subscriber address DA is converted into address information RDA having a smaller number of bits than that (S2).

Next, the selector 15 writes the address information RDA into the VCI of the header of the BOM cell stored in the buffer 14 (S3). By the above operation, as shown in FIG. 3, the called subscriber address stored in the information field of the BOM cell is converted into address information RDA having a smaller number of bits, and the address information RDA is converted.
Can be added to the VCI in the header of the BOM cell.

Next, the operation of routing a cell based on the above address information RDA will be described with reference to FIG. The routing processing unit 21 in the message handler reads the address information RDA from the header of the BOM cell in which the address information RDA degenerated by the DA-RDA conversion circuit described above is written, and searches the routing table 22 with the address information RDA. Check the cell destination. Here, the routing table 22 is a table showing a correspondence relationship between the address information RDA and a routing destination corresponding to the address information RDA, that is, an outgoing route for transmitting the cell, and the address information RDA and the address information RDA at the time of call setting. Information regarding the selected outgoing route is registered in the routing table.

At the time of routing a cell, the routing processing unit 21 does not write to the destination subscriber address DA of 48-bit length added to the information field of the cell but to the VCI of the header having a data length of 5 bytes. Since the routing may be performed based on the address information RDA stored, the routing processing unit 21 can be configured by hardware and high-speed routing similar to ATM exchange can be realized.

As described above, the routing table 2 sets the outgoing route corresponding to the address information RDA of the BOM cell.
When the search is performed from 2, the information is stored in the temporary storage unit 23. At this time, the routing processing unit 21
Stores the message identification information of the BOM cell in order to route the subsequent COM cell or EOM cell to the same outgoing route as the BOM cell.

When the next COM cell is received, the CO
The message identification information in the M cell is compared with the previously received message identification information of the BOM cell, and if they match, the received COM cell is output to the same output route.

Similarly, the routing process is similarly performed for the EOM cell to be received next, and the EOM cell is output to the same outgoing route. When the routing of the EOM cell is completed, the corresponding address information RD from the routing table 22
Delete information on A and its routing destination.

FIGS. 7A and 7B show a DA-RDA conversion table in RAM or CAM (Content Addressable Memory).
It is explanatory drawing at the time of storing in. Here, the CAM is a memory element capable of reading an address from data. When the above DA-RDA conversion table TB is stored in the RAM, it is necessary to store the incoming subscriber address DA as address data and the corresponding address information RDA as data. If there are many, there is a problem that the memory capacity becomes enormous.

On the other hand, when the memory is composed of CAM, the address can be read from the data, so that the called subscriber address having a large amount of information is stored as data, and the corresponding address information RDA is used as the address data. By storing it, the required CAM memory capacity can be reduced.

Therefore, by using the CAM, the capacity of the memory for storing the DA-RDA conversion table in the message handler can be greatly reduced.

[0029]

According to the present invention, in the subscriber line switch, the destination subscriber address of the connection type cell is converted into address information having a smaller amount of information than the destination subscriber address, thereby speeding up the cell routing process. can do. Also, since the amount of address information is reduced,
The capacity of the memory for storing such information can be reduced.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a configuration diagram of an ATM switching network according to an embodiment.

FIG. 3 is a configuration diagram of a DA-RDA conversion circuit.

FIG. 4 is a diagram showing a configuration of a DA-RDA conversion table.

FIG. 5 is a flowchart of DA-RDA conversion processing.

FIG. 6 is an explanatory diagram of routing based on address information RDA.

FIG. 7: DA-RDA conversion table in RAM or CAM
It is explanatory drawing at the time of storing in.

[Explanation of symbols]

 1 address conversion means 2 routing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Kuroyanagi 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Kazuo Hatsukano, 1015, Kamedotachu, Nakahara-ku, Kawasaki, Kanagawa Prefecture Fujitsu Limited ( 72) Inventor Ken Kawasaki 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (3)

[Claims] 1. In a switching network for providing connection communication and connectionless communication, destination subscriber address information added to a connectionless cell is stored in a subscriber line exchange with a smaller amount of information than the information. Addressing means (1) for converting into address information capable of specifying a called subscriber, and routing means (2) for routing a corresponding cell to a predetermined output route based on the converted address information. Message processing method for connectionless communication. 2. The address conversion means (1) stores address information obtained by converting the called subscriber address stored in the information field of the leading cell in the header of the cell, and the routing means (1). 2. The message processing method in connectionless communication according to claim 1, wherein 2) routes the cell and a subsequent cell to a predetermined output route based on the address information stored in the header. 3. The message processing method in connectionless communication according to claim 1, wherein the address conversion means (1) stores a conversion table of the called subscriber address information and the address information in the CAM.