JPH0823349A - Multiplexed identifier providing device - Google Patents

Abstract

PURPOSE:To use all numbered resources assigned to each channel by managing and assigning an available idle multiplexed identifier for each outgoing channel and giving it to a received packet newly. CONSTITUTION:Incoming side connection servers 5-8 accommodate incoming lines 1-4 and a cell-processed PDU received from the incoming lines 1-4 is subjected to routing processing, the label is rewritten into that of a VPI/VCI of outgoing lines 14-17 and a cell is transferred to an ATM switch 9. Outgoing side connection servers 10-13 receive a cell from the ATM switch 9 and sent to the outgoing lines 14-17 to be accommodated. In this case, at each combination between the multiplex identifier of the received packet and the incoming line number, the assigned multiplex identifier is newly provided to the received packet. Thus, the number resource assigned to each line is all used. Furthermore, the processing overhead is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex identifier assigning device, and more particularly to a multiplex identifier assigning device which makes it possible to efficiently use the number resource of the multiplex identifier in packet communication for multiplexing and transferring packets.

[0002]

2. Description of the Related Art A multiplexing identifier is a number for uniquely identifying a packet multiplexed on one line. When different lines are exchange-connected, the lines are switched, so that the same multiplex identifier used in a plurality of incoming lines may be duplicated in an outgoing line. In order to prevent this, conventionally, the method of limiting the allocation range of the number of the multiplexing identifier given to the incoming line for each outgoing line or centrally managing the assigned numbers of all incoming lines has been adopted. The technology behind this is, for example, "Trend of ATM communication technology-toward development to high-speed broadband system" (Journal of the Institute of Electronics, Information and Communication Engineers Vol.71, No.8, pp.806-814,1988). Year) etc.

[0003]

Of the above-mentioned conventional techniques,
In the method of limiting the assigned number of the multiplexing identifier for each outgoing line, the assigned number is limited on the incoming line side, which causes a division loss and cannot effectively use all number resources. There was a problem that the number of allocations had to be changed according to the change. Further, the method of concentrating the number management on a plurality of incoming lines requires communication between the common management part and a plurality of incoming lines, resulting in an overhead in processing, and a multiplexing identifier for one line. Since the numbers are assigned to all the incoming lines, there is a problem that the number resources are not effectively used, and further, all the functions are stopped when the processing of the common management unit fails. The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the above-described problems in the conventional technique and to exchange a plurality of incoming lines and outgoing lines connected to the front stage and the rear stage of a switch. An object of the present invention is to provide a multiplex identifier assigning device that makes maximum use of the multiplex identifier assigned to each line when connecting.

[0004]

The above objects of the present invention are as follows:
In a packet switch that exchanges packets that are multiplexed and transferred using a multiplexing identifier on the same incoming or outgoing line, it is located in front of the switch and manages and assigns an available multiplexing identifier for each incoming line. Means, means for assigning the assigned multiplex identifier and incoming line number to the packet, means for managing and assigning a free multiplex identifier, which is located after the switch and can be used for each outgoing line, and the received packet And a means for newly assigning the assigned multiplex identifier to the received packet for each combination of the multiplex identifier and the incoming line number.

[0005]

The multiplexing identifier assigning device according to the present invention has an advantage that all number resources assigned to each line can be used. Further, since the number can be independently assigned to each incoming line, the processing overhead can be reduced as compared with the case of centralized assignment by the common processing unit.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the embodiment described below, the present invention is applied to the B-ISDN connectionless data service (I
Connectionless server system in which connectionless servers are distributed in order to process the connectionless protocol CLNAP (ITU-T Recommendation I.364) for realizing TU-T recommendation F.812), and the servers are connected by an ATM switch. When applied to. Further, in this connectionless server, processing on the input side and processing on the output side are separated. In the present embodiment, the packet transmitted by the user is once encapsulated in CLNAP-PDU, then cellized by AAL3 / 4 and transferred to the connectionless server system. The connectionless server, after converting the label to the VPI (logical path identifier) / VCI (logical channel identifier) corresponding to the line of the transmission route, according to the telephone number written in the BOM (first cell) of the received cell, then outputs the line. Sent to COM (intermediate cell), EOM
For the (final cell), the header is directly converted into the VPI value, the VCI value, and the MID (multiplexing identifier) value that are routed by the BOM cells that form the same PDU.

FIG. 1 is a diagram showing a system configuration of a connectionless server system according to an embodiment of the present invention. In the figure, 1-4 are incoming lines, 5-8 are incoming lines 1-
Incoming connectionless server that accommodates 4 and performs routing processing of the cellized PDU received from the incoming line, rewrites the label to the VPI / VCI of the outgoing line, and transfers the cell to the ATM switch 9 described later. ATM switches that connect the connectionless servers 5 to 8 on the outgoing side and connectionless servers 10 to 13, which will be described later, 10 to 13 receive cells from the ATM switch 9 described above.
An outgoing connectionless server for sending to the outgoing lines 14 to 17 accommodated therein, and 14 to 17 are outgoing lines, respectively.

FIG. 2 is a diagram showing the configuration of the incoming connectionless servers 5-8 according to the embodiment shown in FIG. In the figure, 20 to 24 are data lines, 25 is a receiving circuit for receiving a signal from the line and taking out a cell after cell synchronization, 26 is a routing circuit based on the telephone number written in the payload of the cell, and an outgoing route. Routing circuit for converting the value of the cell header into VPI / VCI of No. 27, ATM switch 9
To the cell transmitted to the cell, the MID value common to the cell groups forming the same PDU is selected from the free MID values and assigned, and the incoming line number accommodated by the ATM is ATM.
A MID assigning circuit described in the HEC field of the cell header, and a transmitting circuit 28 for transmitting the circuit to the ATM switch 9.

FIG. 3 is a diagram showing the configuration of the outgoing connectionless servers 10 to 13 according to the embodiment shown in FIG. In the figure, 30 to 33 are data lines, and 34 is ATM.
A receiving circuit that receives a cell from the switch 9 and sends it to the MID replacement circuit 35 at the next stage, and 35 is the MID of the received cell
One MID selected from the MID values that are vacant so as to be unique to all cell groups that make up the same PDU, from the value and the incoming line number described in the HEC field.
MID replacement circuit for replacing values, 36 is the MID of the previous stage
The cells received from the reassignment circuit 35 are transferred to the outgoing lines 14 to 17
It shows a transmission circuit for sending to.

FIG. 6 shows an internal configuration of the above-mentioned MID adding circuit 27. In the figure, 40 is a data line for receiving cells from the routing circuit 26, 41 is a data line for transferring cells to the transmission circuit, and 42 to 44 are processors 46 described later.
Is a data line for reading / writing data, 45 is a cell buffer, 46 is a processor that executes a processing flow described later (see FIG. 4), and 47 is an empty MI that manages an empty MID value.
D value FIFO, 48 is VPI / VCI / of the received cell
9 shows a temporary table for temporarily saving a set of an MID value and an MID value currently allocated for use.

The MID assigning circuit 2 in the connectionless server system according to the present embodiment configured as described above.
The operation of No. 7 will be described below with reference to the flowchart shown in FIG. Here, regarding the received cell, first,
Sort by case according to segment type (Step 10
0). According to this result, the receiving cell is BOM, COM, E
In the case of OM, steps 101, 106 and 11 respectively
Control is transferred to the process of 0. In step 100, the receiving cell is B
If it is determined to be OM, first, the empty MID value FIFO4
7. Read the available MID values from 7 (step 10
1). As a result, in the branch of step 102, when there is no free MID number, the cell is discarded and the process ends. On the other hand, if there is a free MID number, the VPI value, VCI value, MID value of the receiving cell and the MID allocation value obtained from the FIFO 47 are registered in the temporary table 48.
(Step 103). Then, in step 104, the assigned MID value is added to the cell header, the incoming line number is set in the HEC field (step 105), and the process is terminated.

In step 100, the receiving cell is set to COM.
If it is determined that the MID allocation value corresponding to the VPI value, the VCI value, and the MID value described in the reception cell exists in the temporary table 48, it is first searched (step 106). As a result, at the branch of step 107, if there is no registration, the cell is discarded and the process ends. On the other hand, if there is registration, the MID value registered in the temporary table 48 is added to the cell header of the cell (step 108), and the incoming line number is set in the HEC field (step 109). The process ends.

In step 100, the receiving cell is the EOM.
If it is determined that the MID allocation value corresponding to the VPI value, the VCI value, and the MID value described in the receiving cell exists in the temporary table 48, it is first searched (step 110). As a result, if there is no registration at the branch of step 111, the cell is discarded and the process ends. On the other hand, if the cell is registered, the MID value registered in the temporary table 48 is added to the cell header of the cell (step 112), and the incoming line number is set in the HEC field (step 113). After that, the VPI value, VC of the reception cell registered in the temporary table 48
The I value, the MID value, and the allocated MID value corresponding thereto are erased (step 114), and the empty MID value FIFO 47 is entered.
The used MID value is returned (step 115) and the process ends.

FIG. 7 shows the internal structure of the MID replacement circuit 35 described above. In the figure, 50 is a data line for receiving cells from the receiving circuit 34, 51 is a data line for transferring cells to the transmitting circuit, 52-54 are data lines for the processor 56, which will be described later, to read / write data from, and 55 is a cell buffer. , 56 is a processor for executing a processing flow described later (see FIG. 5), 57 is a free MID value FIFO for managing free MID values, and 58 is an incoming line number / VPI / of the received cell.
7 shows a temporary table that temporarily saves a set of a VCI / MID value and a MID value currently allocated for use. The operation of the MID replacement circuit 35 in the connectionless server system according to the present embodiment configured as described above will be described below with reference to the flowchart shown in FIG. Here, when a cell is received from the ATM switch 9, the process branches depending on the type of cell (step 200). As a result, when the receiving cell is BOM, COM or EOM, the control is shifted to the processing of steps 201, 206 and 210, respectively.

When it is determined in step 200 that the received cell is the BOM, the empty MID value is first read from the empty MID value FIFO 47 (step 201). As a result, in the branch of step 202, when there is no free MID number, the cell is discarded and the process ends. on the other hand,
If there is a free MID number, the temporary table 48
The VPI value, the VCI value, the MID value / the incoming line number of the receiving cell and the MI obtained from the FIFO 47 corresponding thereto
The D value is registered (step 203). Then assign M
The ID value is added to the cell header (step 204), and the process ends.

In step 200, the receiving cell is set to COM.
If it is determined that the MID to be reassigned is searched in the temporary table 48 using the incoming line number / VPI value / VCI value / MID value described in the receiving cell as a key (step 20).
6). As a result, if the MID to be replaced is not registered, the cell is discarded (step 207) and the process ends. On the other hand, if the MID is registered, the MID value is replaced with the MID value (step 208).

In step 200, the receiving cell is the EOM.
If it is determined that the MID to be replaced is searched in the temporary table 48 using the incoming line number / VPI value / VCI value / MID value described in the receiving cell as a key (step 21).
0). As a result, if the MID to be replaced is not registered, the cell is discarded (step 211) and the process ends. On the other hand, if the MID is registered, the MID value is replaced with the MID value (step 212). After that, the used M registered in the temporary table 48
ID value and incoming line number / VPI value / VCI corresponding to it
The value / MID value is deleted (step 214). Then, the used MID value described above is returned to the FIFO 47 (step 215).

According to the above embodiment, the connectionless server system in which the connectionless servers are arranged in a distributed manner to process the connectionless protocol CLNAP for realizing the B-ISDN connectionless data service, and the servers are connected by the ATM switch. In, it is possible to obtain the effect that all the number resources assigned to each line can be used. Further, since the numbers can be independently assigned to each incoming line, the processing overhead can be reduced as compared with the case of centralized assignment by the common processing unit. It is needless to say that the above embodiment shows one example of the present invention, and the present invention should not be limited to this.

That is, in the above embodiment, the present invention is arranged such that connectionless servers are distributed for processing the connectionless protocol CLNAP for realizing the B-ISDN connectionless data service, and the servers are connected by the ATM switch. The description has been given by taking as an example the case where it is applied to the connectionless server system described above. However, since the multiplexing identifier only needs to be unique in each link-by-link section, it is also possible to transfer it on the ATM by the IP protocol or the X25 protocol. It is possible to use the multiplexed identifier by using the lower layer, and the present invention can be applied based on this.

[0020]

As described above in detail, according to the present invention, when a plurality of incoming lines and outgoing lines connected before and after the switch are exchange-connected, a multiplexing identifier assigned to each line. This has the remarkable effect of realizing a multiplex identifier assigning device that can maximize the use of the above.

[Brief description of drawings]

FIG. 1 is a diagram showing a system configuration of a connectionless server system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an incoming connectionless server shown in FIG.

FIG. 3 is a diagram showing a configuration of an outgoing connectionless server shown in FIG.

FIG. 4 is an operation flowchart of the MID adding circuit shown in FIG.

5 is an operation flowchart of the MID replacement circuit shown in FIG.

FIG. 6 is a diagram showing an internal configuration of the MID addition circuit shown in FIG.

FIG. 7 is a diagram showing an internal configuration of the MID replacement circuit shown in FIG.

[Explanation of symbols]

 1 to 4 incoming line 5 to 8 incoming side connectionless server 9 ATM switch 10 to 13 outgoing side connectionless server 14 to 17 outgoing line 25,34 receiving buffer 26 routing circuit 27 MID assigning circuit 28,36 transmitting circuit 35 MID replacement Circuit 45,55 Cell buffer 46,56 Processor 47,57 Free MID value FIFO 48,58 Temporary table

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H04Q 3/52 101 Z 9566-5G (72) Inventor Kuniaki Kishino 1-7 Toranomon, Minato-ku, Tokyo No. 12 Oki Electric Industry Co., Ltd. (72) Inventor Ken Tanaka 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Jiro Aso 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Kazutaka Hanaki 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (1)

[Claims] 1. A packet switch that switches packets that are multiplexed and transferred by a multiplexing identifier on the same line of an incoming line or an outgoing line, and is located in front of a switch.
A means for managing and assigning an available multiplexing identifier for each incoming line, a means for assigning the assigned multiplex identifier and an incoming line number to a packet, and is located after the switch and can be used for each outgoing line And a means for managing and allocating a free vacant multiplexing identifier, and a means for newly assigning the allocated multiplexing identifier to the received packet for each combination of the multiplexing identifier and the incoming line number of the received packet. A characteristic multiplex identifier assigning device.