JP2610859B2 - Self-routing exchange - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] In the present application, control information added to input information is autonomously switched by each self-routing module and transmitted to an output terminal specified by the control information. In the self-routing exchange, an optional service command is included in control information to add a function of executing a scheduled optional service to a data packet.
An optional module is externally provided between the last modules, and the optional module has an optional service function.

[Industrial applications]

The present invention relates to a self-routing switch, and more particularly to a self-routing switch suitable for high-speed packet switching.

In telephone switching (circuit switching), once a communication path is set, the communication path is maintained until the end of the call.

In the case of multiplex transmission, each call (channel) is switched at high speed. However, since the position of each call on the frame is constant, simple sequential switching is sufficient.

On the other hand, in packet switching, each packet has its own destination, and the destination of each packet viewed in chronological order varies, so the above two methods are not adopted, and the processor once loads it into its memory, A method of distributing to outgoing lines (memory exchange) is employed.

However, this memory exchange method requires time and is not suitable when high-speed exchange is required.

The self-routing switch is particularly suitable for high-speed switching to a different outgoing line for each packet, such as high-speed packet switching, and when it is not desirable to centrally control the communication path from outside using software. In the self-routing switch, a correspondence table of a virtual call number (VCN) of each call as an identification number and a number of the outgoing line is created, and when the call of the virtual call number arrives, the correspondence table is referred to the outgoing line number. , And performs packet switching by sending the call to an outgoing line.

[Conventional technology]

FIG. 3 shows the above-described conventional self-routing switch, which is connected to a corresponding outgoing route side by routing information (RH) which is information indicating an outgoing line of each self-routing module. A self-routing module SRM _ij in units of (first stage), k × y (second stage), and z × g (third stage) is configured by reverse shuffle connection as shown in the figure. This module SRM functions as a packet switch.

When a call is generated from a terminal device (not shown) prior to data transfer and call setup is performed, the signal control unit SGC transmits a virtual call number (VCN) in a control packet for the call setup via a signaling channel. Then, a conversion table for a new virtual call number at the outgoing side of the exchange is created based on the received virtual call number. Processor CPU
Assigns the conversion table and the routing information for passing through the exchange to the converter CNV connected to the terminal device in consideration of the call situation.

In the converter CNV, based on the header information of the input data from the data channel, as shown in FIG. 4, a conversion table is searched from the header A which is the control information added to the input data I, and a new output The header B and the routing information “5, 3, 7” are transmitted as control information before the packet information.

As shown in FIG. 5, the exchange as a whole receives the information and first selects and outputs the outgoing line "5" based on the information "5" in the first-stage self-routing module SRM. 2
In the level, the outgoing line “3” is selected based on the information “3”, and in the third level, the outgoing line 7 is selected and output based on the information “7”.
Regarding the incoming line, since the fifth (# 5) self-routing module of the second stage is connected to the first (# 1) self-routing module of the first stage, The incoming line becomes "1". Similarly, since the third self-routing module of the third stage is connected to the fifth (# 5) self-routing module of the second stage, the incoming line of the third-stage self-routing module is connected. Is "5".

The specific configuration of each of the self-routing modules SRM is shown in FIG. 6 (in this example, the first row in FIG. 3 is shown), and the ROT is based on the routing header information. FIFO memory M as buffer
(This is provided for the outgoing line of the module)
Is a selector for selecting one of the above and storing the data. The FIFO memory M stores the data in the controller CT when the data is stored.
Send a transfer request signal to L. The controller CTL determines this transfer request and selects one of the Fs selected by the selector SEL.
Select the IFO memory M.

An example of the controller CTL is shown in FIG. 7, and a transfer request from the FIFO memory M (* 1, * 2,... * N-1, * n).
Are shifted one by one and input to each selector (SEL) 10, and are sent to an adder (ADD) 14 via a fixed priority circuit 12 and an encoder 13 based on a command value from a counter 11. Adder 14
In FIG. 6, the command value of the counter 11 and the transfer request number (* 1, * 2,... * N-1, * n) indicated by the output of the encoder 13 are added to generate the FIFO memory number. To the selector SEL. The command value to the selector SEL is returned to the controller (CNT) 15 to output a transfer OK signal to the FIFO memory M that has requested the transfer. Then, when receiving the signal indicating the completion of the transfer from the FIFO memory M, a signal for increasing the count value of the counter 11 is sent to the counter 11 this time.

Thus, the selection signal of the selector 10 is increased by, for example, one.

In this case, when two or more transfer requests overlap,
The fixed priority circuit 12 sends a transfer request signal to the encoder 13 with a predetermined priority (for example, from the top in the drawing).

In this way, a plurality of self-routing modules SR
M autonomously switches to transfer data packets.

[Problems to be solved by the invention]

In the above-mentioned conventional self-routing exchange, when a specific service is provided to the subscriber as an optional function, it is necessary to add a function for performing a specific service to the self-routing module itself on hardware in advance.

For this reason, the amount of hardware of the module increases and the entire exchange becomes a large-scale uneconomical device.

In addition, when a service is further added, there is a problem that each module must be replaced, and it is not possible to flexibly cope with the expansion of the service.

Accordingly, it is an object of the present invention to realize a self-routing exchange with a small amount of hardware that can flexibly cope with optional services.

[Means for solving the problem]

The self-routing switch according to the present invention for achieving the above object autonomously switches the data packet based on routing information (RH) added to the data packet, and switches the data packet input from an incoming line. In a self-routing exchange having a self-routing module composed of a plurality of stages for outputting to an outgoing line instructed by the routing control information, an input line is connected to the last outgoing line of the self-routing module, An output line is connected to the input line at the forefront of the module, executes a predetermined service for a data packet input from the input line, outputs a data packet to the output line, and temporarily stores a data packet to be received. Storage means (1), based on the service request information of the stored data packet; External service providing unit consisting the execution means (2,3) for executing come predetermined service (O
M), and information for requesting the predetermined service for a data packet connected to the input line at the forefront of the self-routing module and for requesting execution of the predetermined service, and routing information for specifying the output line. And additional means (CNV) for performing the operations.

[Action]

In the self-routing exchange of the present invention shown in FIG.
In the additional means, information for requesting a predetermined service to the input data packet and the self-routing module SR
Routing information for designating the last output line of M is added.

Based on this, each self-routing module SRM determines a route toward the service providing means OM for executing a predetermined service, and in the service providing means OM, performs a predetermined service such as a CRC check on the data packet. To replace the header information and
Send to SRM to execute the service.

〔Example〕

Hereinafter, an embodiment of the self-routing switch according to the present invention will be described.

FIG. 2 shows an embodiment of the self-routing switch of the present invention shown in FIG. 1, and in this embodiment, the self-routing module SRM of the conventional self-routing switch shown in FIG. Two predetermined modules SRM _1j and SR
And connect an external option modules OM as a service providing means between the M _3j. For this external connection, _{connect one} of the outgoing lines of module SRM _3j to option module O
As the incoming line of M, one of the incoming lines of the module SRM _1j is connected so as to be the outgoing line of the module module OM.

In this optional module OM, a FIFO memory 1 is provided to create a data buffer, and the data once stored therein is taken into a processor (CPU) 2, and the processor 2 executes an optional service (OS) constituted by hardware or software. ) It is configured to execute a predetermined function set in the unit 3 and transmit the result.

Next, a case where an optional service is received in this embodiment will be described.

For example, a CRC (redundancy check:
When the optional service request of the Cyclic Redundancy Check) code is set, the signal control unit SGC uses the virtual call number (VCN) in the received control packet to convert the converter CNV connected to the terminal device via the processor CPU. When the control information to the option module OM, that is, the routing information (RH) and the optional service request are set, and the data packet is received by the converter CNV,
The routing information and the optional service request are added to the data packet, and the first stage, for example, the module SRM ₁₁
Send to In the module SRM ₁₁ , for example, the module SRM ₂₁ is selected from the routing information, the module SRM ₂₁ further selects the module SRM _3j , and then the module SRM _3j selects the option module OM.

The data packet from the terminal device that has issued the request for the optional service according to the routing information is
Once stored in the FIFO memory 1 in the option module OM, the processor 2 and the option service unit 3
For example, after executing a CRC code check, new routing information is replaced and sent to the module SRM _1j . When an error is detected by CRC code check,
Discard the data packet.

When this optional service is broadcast,
The optional service unit 3 stores data packets to be broadcast, and the processor 2 may sequentially add various routing information to the data packets.

It goes without saying that various optional services can be set in the optional module OM in addition to the CRC code check and the broadcast communication.

The normal replacement operation in the above embodiment is the same as the operation of the conventional example described with reference to FIG.

〔The invention's effect〕

As described above, according to the self-routing switch of the present invention, the option module for executing the optional service is externally attached to the conventional module-structured self-routing switch. And the device configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle of a self-routing switch according to the present invention, FIG. 2 is a block diagram showing one embodiment of a self-routing switch according to the present invention, and FIG. 3 is a configuration of a conventional self-routing switch and its external control. FIG. 4 is a block diagram showing the mechanism, FIG. 4 is a diagram showing the principle of operation of the converter used in FIG. 3, FIG. 5 is a diagram showing the principle of operation of the exchange shown in FIG. 3, FIG. FIG. 7 is a diagram showing a configuration of each self-routing module used in the drawing. FIG. 7 is a diagram showing a configuration of a controller CTL used in FIG. 1 and 2, SRM is a self-routing module, and OM is an optional module. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Osamu Isono 1015 Ueodanaka Nakahara-ku, Kawasaki City Inside Fujitsu Limited (72) Inventor Toshimasa Fukui 1015 Kamidadanaka Nakahara-ku Kawasaki City Fujitsu Limited (72) Inventor Tetsuo Nishino 1015 Uedanaka, Nakahara-ku, Kawasaki City Fujitsu Limited (56) References JP-A-59-23657 (JP, A) JP-A-57-164642 (JP, A) IEEE Journal on Selected Areas in Communications , SAC-4 [8] (1986) p. 1373-1380

Claims (1)

(57) [Claims] An autonomous switching of the data packet based on routing information (RH) added to the data packet, and output of the data packet input from an incoming line to an outgoing line specified by the routing information. In a self-routing switch having a self-routing module having a plurality of stages, an input line is connected to a last outgoing line of the self-routing module, and an output line is connected to a foremost input line of the self-routing module. A storage unit (1) for executing a predetermined service on a data packet input from an input line, outputting a data packet to the output line, and temporarily storing a received data packet; An execution means (2, 3) for executing a predetermined service based on the service request information. Service providing means (OM) connected to the input line at the forefront of the self-routing module, for designating information for requesting the predetermined service for a data packet for requesting execution of the predetermined service, and specifying the outgoing line. Additional means for adding routing information (CNV)
And a self-routing exchange characterized by the following.