CN1124004C

CN1124004C - Business adaptable interface and synchronous broadcast method

Info

Publication number: CN1124004C
Application number: CN98113212A
Authority: CN
Inventors: 王占强
Original assignee: Huawei Technologies Co Ltd
Current assignee: Global Innovation Polymerization LLC; Tanous Co
Priority date: 1998-05-13
Filing date: 1998-05-13
Publication date: 2003-10-08
Anticipated expiration: 2018-05-13
Also published as: CN1235454A

Abstract

The present invention relates to an ATM service adaptable interface and a method for realizing multicast. The flag information of multicast and broadcast is recognized by a broadcast table unit 3. Based on the flag information of multicast and broadcast, VPI/VCI values are switched and synchronously output to a multi-way cell stream combined circuit unit 6 to be combined and respectively output to an FIFO receiving memory of a multicast or broadcast passage. In the present invention, a multicast cell and a broadcast cell can be directly detected, and multicast and broadcast processing is automatically performed, which reduces the load of an ATM service multiplexer and guarantees the synchronization of multicasting multi-way service.

Description

Professional adaptable interface and synchronized broadcast method thereof

Technical field

The present invention relates to network technology, the implementation method that is specifically related to the professional adaptable interface of a kind of ATM and broadcasts or broadcast together.

Background technology

The professional adaptable interface of ATM comes down to provide for atm network and non-atm network (PSTN, DDN, Broadcasting Cable Network etc.) interface of an interconnection and interflow.The kind of the professional adaptable interface of ATM and performance thereof are to weigh the importance of ATM access switch performance.A lot of business except will supporting the communication between the point-to-point, are also wanted the communication of support point to multiple spot as video request program (VOD), video conferencing etc., and promptly the cell that comes from a certain input port need be in a plurality of (with broadcasting) or all (broadcasting) output port output.Present ATM switch is all supported mostly with broadcasting and broadcast capability.Support is broadcast together and the professional adaptable interface module of ATM of broadcast capability (hereinafter to be referred as the professional adaptation module of ATM) but do not see as yet.In actual applications, make the professional adaptation module support of ATM with broadcasting and broadcast capability is very necessary and significant.

The professional adaptation module of ATM is received on the port of ATM switch after generally all merging into high-speed information element by the professional multiplexer of ATM, and vice versa.Specifically, one end of the professional adaptation module of ATM connects multimedia terminals such as the speech, data, image of non-ATM, and the atm cell stream of other end output is connected on the switching port of ATM switch after the professional multiplexer of ATM merges into high-speed information element stream (155Mbps or 622Mbps); Otherwise the cell of a port output of ATM switch will enter the professional adaptation module of ATM after the tap through the professional multiplexer of ATM, and information such as the speech of the non-ATM of output, data, image are to non-ATM terminal after the professional adaptation module of ATM is handled.Owing to only have a cell interface between professional adaptation module of ATM and the professional multiplexer of ATM, concerning do not support with broadcast and the professional adaptation module of the ATM of broadcast capability, in order to realize that multichannel business same broadcast and broadcast, must on the cell interface, repeatedly repeat to send that same cell realizes cell broadcasts and broadcast together by the professional multiplexer of ATM.When receiving one with after broadcasting cell, the professional multiplexer of ATM must temporarily stop the transmission to other cell, repeatedly repeats to send same with broadcasting a plurality of together the broadcast passages of cell to professional adaptation module.This practice has not only increased the burden of the professional multiplexer of ATM, and has caused with asynchronous (the time delay difference is big) broadcast between the multichannel business, and way is many more, influences big more.Fig. 1 has provided this schematic diagram with broadcasting method of prior art, and in order to realize the broadcasting to a professional adaptation module M passage, the professional multiplexer of ATM need repeat to send broadcasting cell M time.

Above-mentioned existing techniques in realizing has serious defective with the method for broadcasting and broadcast, and tracing it to its cause is that it repeats to send same cell with multicast function by the professional multiplexer of ATM and realizes because the professional adaptable interface module of ATM can not be supported same multicast function.

Summary of the invention

The object of the present invention is to provide the professional adaptable interface of a kind of ATM, this interface equipment can overcome the defective of prior art, by broadcast same the broadcasting and broadcast transmitted that sign analysis can be realized quickly and easily together between atm network and non-atm network.

Another object of the present invention is to provide a kind of is realized with the method for broadcasting and broadcasting by the professional adaptable interface of ATM, the defective of this method clothes prior art, in the burden that effectively alleviates the professional multiplexer of traditional ATM, can guarantee with the reliable synchronization of broadcasting between the multichannel business.

First purpose of the present invention is to realize like this, construct the professional adaptable interface of a kind of ATM, it is characterized in that comprising shift circuit unit 1, header latch circuit units 2, with broadcasting information inquiry circuit unit (calling the broadcasting table in the following text) 3, descending VPI/VCI (VPI/VCI) switch circuit units 4, processor interface circuit unit 5, multichannel cell stream combiner circuit unit 6, wherein: the input of described shift circuit unit 1 connects the output of the professional multiplexer of ATM, described cell latch circuit units 2 latchs header from each cell of the professional multiplexer of ATM by described shift circuit unit 1, the input of described broadcasting table 3 connects the output of described header latch circuit units 2 in order to the header of storage in the described header latch circuit units 2 is discerned, the output that the input port of described descending VPI/VCI switch circuit units 4 is connected to described broadcasting table 3 is in order to according to same broadcast of identifying and broadcast flag information is finished and correspondingly switched with the VPI/VCI that broadcasts passage, the output of described descending VPI/VCI switch circuit units 4 is connected to the input of described multichannel cell stream combiner circuit unit, in order to will output to synchronously through a plurality of vpi/vci values of VPI/VCI conversion in the described multichannel cell stream combiner circuit unit, another input of described multichannel cell stream combiner circuit unit connects the cell payload output of described shift circuit unit 1, and a plurality of outputs of described multichannel cell stream combiner circuit unit are connected respectively to the read/write port of the reception FIFO memory of corresponding passage.

Another object of the present invention is to realize like this, construct a kind of method of being broadcast together by the professional adaptable interface realization of ATM, the professional adaptable interface of described ATM comprises that shift circuit unit 1, header latch circuit units 2, broadcasting table 3, descending VPI/VCI switch circuit units 4, processor interface circuit unit 5, multichannel cell stream combiner circuit unit 6, described realization may further comprise the steps with the method for broadcasting:

Latch the header of each cell that comes from the professional multiplexer of ATM by described header latch circuit units 1, and identify wherein same broadcasting and broadcast flag information by described broadcasting table unit 3;

Described descending VPI/VCI switch circuit units 4 is according to same the broadcasting of being identified by described broadcasting table unit 3 and broadcast flag information, a vpi/vci value is converted to a plurality of corresponding with broadcasting or the vpi/vci value of broadcast channel, and output to multichannel cell stream combiner circuit unit 6 synchronously;

The cell payload that described multichannel cell stream combiner circuit unit 6 will transform a plurality of headers of back output synchronously and shift circuit output synthesizes and outputs to respectively in the reception FIFO memory of the passage of broadcasting together or broadcasting and goes.

Professional adaptable interface and the synchronized broadcast method thereof that provides of the present invention is provided, have the following advantages: directly detect with broadcasting and broadcast cell by the professional adaptable interface of ATM provided by the invention, and finish corresponding voluntarily with broadcasting and broadcast processing, not only alleviated the burden of the professional multiplexer of ATM, and guaranteed with broadcast between the multichannel business synchronously.

Description of drawings

Below in conjunction with drawings and Examples, further specify characteristics of the present invention, in the accompanying drawing:

Fig. 1 is that prior art is the broadcasting that realizes a business board M passage, and the professional multiplexer of ATM need repeat to send the situation schematic diagram of broadcasting cell M time.

Fig. 2 shows the present invention and realizes that with broadcasting method multichannel cell broadcasting reaches the theory diagram with multicast function.

Fig. 3 shows the example that the present invention is applied to 12 road circuit emulation service plates with broadcasting method.

Embodiment

As shown in Figure 2, after a cell receiving cycle begins (concerning the professional adaptation module of ATM), same broadcasting module on the professional adaptation module latchs the VPI/VCI field of importing in the cell header at particular time-slot, according to VPI/VCI field numerical value, by broadcasting the information inquiry circuit unit together is that radio unit 3 identifies with broadcasting and broadcast flag information, according to broadcasting and broadcast flag information together, finishing VPI/VCI by descending VPI/VCI switch circuit units 4 switches, described VPI/VCI switching essence is meant from a vpi/vci value and transforms to another vpi/vci value, so the VPI/VCI switching also can claim the VPI/VCI conversion.Switch the synchronous multichannel cell head of exporting in back (at this moment, each header comprises a vpi/vci value respectively, the vpi/vci value of each header can not be identical) thus synthesize with the cell load of shift circuit unit 1 output and form new multichannel cell and flow, the described synthetic header and the cell payload that contain the respective channel vpi/vci value of being meant converges the new cell of composition, each new cell with entered comparing of cell combiner circuit originally with broadcasting cell, just vpi/vci value has changed, and has become the cell that contains the respective channel vpi/vci value.Multichannel cell stream can be written into simultaneously in a plurality of fifo circuit (see figure 3)s and go, and finishes with broadcasting and broadcast capability.Broadcasting table unit 3 and descending VPI/VCI switch circuit units 4 have a processor interface circuit unit 5 with the external treatment machine circuit, so that the permission outside processor dynamically updates wherein broadcast message and descending VPI/VCI handover information.As for of renewal or the inquiry of external treatment machine circuit, determine by master control to the inside CAM and the table of the VPI/VCI in the descending VPI/VCI switch circuit units of broadcasting table unit 3.

In conjunction with Fig. 3, one embodiment of the present of invention are described at last.

Fig. 3 shows the example that the present invention is applied to 12 road circuit emulation service adaptation module with broadcasting method.Adopt a slice CAM (MUSIC2480) and a slice FPGA (EPF10K20) to design the broadcasting and the same multicast function of 12 road cells herein.(the CAM full name is a content adressable memory, and CAM can support more VPI/VCI to connect than dual port RAM.CAM is 64 bit widths, and dual port RAM only has (12+6) bit width.)

Suppose by the VPI/VCI that the professional multiplexer of ATM comes to be that 8/8 cell needs with broadcasting the 1st, 3,5 ports (1-12 port), 1st, the VPI/VCI of 3,5 port correspondences is respectively 111/111,333/333,555/555, so, corresponding VPI/VCI is that 8/8 list item should be designed to B " 000000010101 " among the CAM, and 1,3,5 passage vpi/vci values should extend this as 111/111,333/333,555/555 respectively in the descending VPI/VCI table.

As shown in Figure 3, after this cell receiving cycle begins (concerning the circuit emulation service adaptation module), the same broadcasting module on the circuit emulation service adaptation module latchs the VPI/VCI field 8/8 (the VPI/VCI field is at the 5-28 of header bit) of input cell header at the 4th rising edge clock thereafter.With what latch 8/8 is that content is looked into CAM, and it is output as 12 the same flag information B " 000000010101 " that broadcasts.Descending VPI/VCI commutation circuit is according to the output B " 000000010101 " of CAM, select the vpi/vci value output of corresponding 1,3,5 passages in the VPI/VCI table, promptly synchronously three of output to carry VPI/VCI respectively be 111/111,333/333,555/555 header, the cell payload of these three headers and shift circuit output converges has formed new multichannel cell stream, be written into simultaneously in three fifo circuits and go, finish same multicast function 1,3,5 passages.The implementation method of broadcasting is identical with synchronized broadcast method.

Compare with legacy interface, interface provided by the invention has only increased a slice CAM (MUSIC2480) and a slice FPGA (EPF10K20) on hardware cost.

Claims

1, the professional adaptable interface of a kind of ATM, it is characterized in that comprising shift circuit unit (1), header latch circuit units (2), broadcasting table unit (3), descending VPI/VCI switch circuit units (4), processor interface circuit unit (5), multichannel cell stream combiner circuit unit (6), wherein: the input of described shift circuit unit (1) connects the output of the professional multiplexer of ATM, described header latch circuit units (2) latchs header from each cell of the professional multiplexer of ATM by described shift circuit unit (1), the input of described broadcasting table unit (3) connects the output of described header latch circuit units (2) in order to the header of storage in the described header latch circuit units (2) is discerned, the output that the input port of described descending VPI/VCI switch circuit units (4) is connected to described broadcasting table unit (3) is in order to according to same broadcast of identifying and broadcast flag information is finished and correspondingly switched with the VPI of broadcasting passage/VCI, the output of described descending VPI/VCI switch circuit units (4) is connected to the input of described multichannel cell stream combiner circuit unit (6), in order to will output to synchronously through a plurality of VPIs/VCI value of VPI/VCI conversion in the described multichannel cell stream combiner circuit unit (6), another input of described multichannel cell stream combiner circuit unit (6) connects the cell payload output of described shift circuit unit (1), and a plurality of outputs of described multichannel cell stream combiner circuit unit (6) are connected respectively to the read/write port of the reception FIFO memory of corresponding passage.

2, the professional adaptable interface of ATM according to claim 1, it is characterized in that, a processor interface circuit unit (5) is arranged between content adressable memory in the described broadcasting table unit (3) and the external treatment machine circuit, be used for the external treatment machine circuit content of described content adressable memory is conducted interviews.

3, the professional adaptable interface of ATM according to claim 1, it is characterized in that, described descending VPI/VCI switch circuit units (4) comprises a VPI/VCI table, a processor interface circuit unit (5) is arranged, so that described VPI/VCI table content is conducted interviews and upgrade between described VPI/VCI table and the external treatment machine circuit by the external treatment machine circuit.

4, a kind of method of broadcasting together by the professional adaptable interface realization of ATM, the professional adaptable interface of described ATM comprises shift circuit unit (1), header latch circuit units (2), broadcasting table unit (3), descending VPI/VCI switch circuit units (4), processor interface circuit unit (5), multichannel cell stream combiner circuit unit (6), and described realization is characterised in that with the method for broadcasting and may further comprise the steps:

1) latchs from the header of each next cell of the professional multiplexer of ATM by described header latch circuit units (1);

2) identify wherein same broadcasting and broadcast flag information by described broadcasting table unit (3);

3) described descending VPI/VCI switch circuit units (4) is according to same the broadcasting of being identified by described broadcasting table unit (3) and broadcast flag information, a VPI/VCI value is converted to a plurality of corresponding with broadcasting or the VPI/VCI value of broadcast channel, and output to multichannel cell stream combiner circuit unit (6) synchronously;

4) described multichannel cell stream combiner circuit unit (6) the cell payload that will transform a plurality of headers of back output synchronously and shift circuit output synthesizes and outputs to respectively in the reception FIFO memory of the passage of broadcasting together or broadcasting and goes.

5, method according to claim 4 is characterized in that, also comprises by the external treatment machine circuit VPI in described descending VPI/VCI switch circuit units (4)/VCI table is conducted interviews and updating steps.