CN100369442C - Method for non-block user data transmission in reverse multiplexing process - Google Patents

Abstract

The present invention relates to a method for non-blocking transmission of user data in a reverse multiplexing process. The present invention comprises the steps of transmitting processing and receiving the processing, wherein the step of transmitting processing comprise: extracting user cells loaded by ICP cells according to a VPI value and a VCI value; determining the number of separated sections of a cell according to the number of links in a group and also loading the number of separated sections into the ICP cells; transmitting the ICP cells. The steps of receiving the processing comprises: extracting the ICP cells; extracting user data from the ICP cells and also filtering and preserving the extracted user data; restoring filtered data into the user cells. The method is free from the influence of an IMA protocol, and can initiate transmission and receiving so long as both terminals can initiate to transmit and receive the ICP cells. The present invention can achieve the aim of non-blocking transmission of the user data by utilizing the bytes of residual link information in the ICP cells to fill the user data.

Description

The method of clog-free transmitting user data in the inverse multiplexing process

Technical field

The present invention relates to a kind of transmission data method, relate in particular to the method for transmission data in the inverse multiplexing process.

Background technology

Show IMA (inverse multiplexing in Inverse Multiplexing over ATM standard 1.0 and 1.1 editions, InverseMultiplexing for ATM) be based on cell an atm cell stream, inverse multiplexing transmits on a plurality of physical connections, and at far-end these cells that transmit on different physical connections is multiplexed into and the original consistent cell flow of order.The inverse multiplexing technology becomes a plurality of connection multiplexings than low rate the higher rate of a logic to connect, and this higher rate value is approximately equal to several low rate value sums of forming inverse multiplexing.

Inserting some IMA Control Protocol cells periodically at the transmitting terminal of IMA is icp cell, by receiving icp cell, finishes the group state, the migration of Link State, and final arrival sends and receives user cell.

The content of icp cell also has A except that header, B, and C, D, 5 category informations such as E, wherein the C class is a link information, is made up of 32 bytes.That is to say that an IMA group is made up of 32 links at most.ICP should reserve the surplus of 32 links.

In the middle of the application of prior art, seldom a group surpasses 16 links, general 4 links, and maximum 8, this is because link is many more, and cost is high more, improves speed and uneconomical with IMA.The actual composition of IMA is not enough half, there is the cell of vacant byte in ICP, so just gives to utilize icp cell to transmit data to have created condition.

Method transmission and receiving subscriber data with ima protocol transmission data are subjected to ima protocol control, stipulate according to agreement, the state transition of having only IMA to organize could send and receiving subscriber data when arriving operating state, when forbidding a group, when group is got back to blocked state by operating state, can stop to transmit and receive data, thereby block user's use.

Summary of the invention

When solving in the prior art with ima protocol transmission data, the problem that can cause user data to block, the invention provides a kind of method of utilizing icp cell to come carrying user data, this method is not subjected to the influence of ima protocol, as long as two ends can begin to send and receive icp cell, just can begin to send and receiving subscriber data, particularly, be to utilize the byte of " link information " remaining in the icp cell to fill user data, thereby reach the purpose of clog-free transmitting user data.

For solving the problems of the technologies described above, provided by the invention in the inverse multiplexing process method of clog-free transmitting user data, comprise sending treatment step and receiving treatment step that wherein said transmission treatment step comprises: extract the user cell with the icp cell carrying according to VPI, VCI value; According to the definite hop count that a cell is split of number of links in the group, and be filled in the icp cell; Send described icp cell; Described reception treatment step comprises: extract described icp cell; From described icp cell, extract user data, the user data that extracts is filtered and preserves; Filtered data is reverted to user cell.

Compared with prior art, the present invention has following beneficial effect: the user data of employing icp cell carrying is not subjected to the influence of ima protocol, icp cell is to send in the cycle, as long as can send and receive icp cell, just can utilize ICP transmission data, and utilize IMA transmission data, when having only the state of waiting until local terminal and far-end group to be operating state, just can transmit data.

Description of drawings:

Fig. 1 is that user data is carried on the position view in the icp cell;

Fig. 2 is that user data specifically carries schematic diagram;

Fig. 3 is that a user cell is carried on 3 schematic diagrames in the icp cell;

Fig. 4 is the data sending processing flow process and receives the handling process schematic diagram;

Fig. 5 is the schematic diagram that direct store method receives data;

Fig. 6 is the schematic diagram that receives data with the method for similar IMA.

Embodiment:

Below in conjunction with accompanying drawing in detail embodiments of the invention are described in detail.

A kind of in the inverse multiplexing process method of clog-free transmitting user data, this method utilizes IMA periodically to send the characteristic of icp cell, user cell is divided into several sections, be carried in the icp cell, this method comprises treatment step that user data is carried in the icp cell and sends and receives icp cell at far-end, and with the consistent treatment step of the data multiplex Cheng Yuyuan data sequence in the icp cell.

Please refer to Fig. 1, for user data is arranged on schematic diagram in the icp cell, each icp cell is made up of 53 bytes, the 18th to n byte carrying " link information ", but n+1 to the 49 byte carrying user data, wherein n is " number of links-1 in the 18+ group ", carrying " link information " and user data be totally 32 bytes, for example organize 4 links for one, preceding 4 bytes of " link information " are information such as Link State, 28 remaining bytes be sky, and this 28 byte just can be used for transmitting user data so.

Because user cell is made up of 53 bytes equally, obviously, an icp cell is to carry not next user cell, so just needs a plurality of icp cells to carry.That is to say, a user cell is divided into several sections, each section is carried by an icp cell.As shown in Figure 2: utilize the 48th and 49 two byte, decide carry in the icp cell of transmission what be which section of which user cell and judging carries in the icp cell that receives is which section of which user cell.

Head: the 8th bit, whether contain the header of 5 bytes in the expression user cell data, " 1 " expression contains header; " 0 " expression does not contain header.

User Cell No.: the 7-1 bit, scope 0-127, what represent that this cell carries is the order of user in ima frame, is which user cell.Because the superframe of IMA is 256, so the scope of user cell is decided to be 0-127, increases in order, and circulation repeatedly.

Segment: the 8-6 bit, scope is 0-7, what represent that this icp cell carries is which section of user cell.If 0, expression contains header, and promptly Head is 1, is expressed as first section simultaneously, if 2, so just represent the 3rd section.Why a user cell is carried by 8 icp cells at most, is to consider if carried by too many icp cell, and efficient just reduces so.

Length: the 5-1 bit, scope 0-31 is illustrated in this icp cell, is used for carrying the byte number of user cell, and promptly the length of the Segment section of User Cell No. cell is Length.

User Data: the user data of the Segment section of the User Cell No. cell of expression carrying, its length is Length.

Why two bytes of overhead are not immediately following in the link information back, but adopt the 48th, 49 bytes, be since can guarantee the judgement of this byte do not organized in the influence of number of links.

Please refer to Fig. 3, be the split process of the 50th user cell: determine that at first a cell can be carried by the least possible several icp cells, as group four links, a 32-4-2 (expense)=26 so, 53/26 to round be 3, therefore needs 3 icp cells.General method according to mean allocation, remaining last icp cell of giving, 53/3 to round be 18,18 bytes that at first will contain the letter head are carried to an icp cell, add the expense of last two bytes, send, send the icp cell of 18 bytes that contain the back then, 17 remaining bytes use the same method and send.

In atm technology, set up the value that Permanent Virtual Channel connects needs VPI (Virtual PathIdentifier Virtual Path Identifier) and VCI (Virtual Channel Identifier virtual path is represented symbol), as long as any one differently just represents different Permanent Virtual Channels among both. all come from same ATM layer with the user data of IMA transmission with the user data of icp cell carrying, its VPI, VCI value can be not identical.Therefore with the user data of IMA transmission with the user data of icp cell carrying, its VPI, VCI value is different, gives specific VPI by setting up Permanent Virtual Channel, the VCI value, according to VPI, which kind of method is the value of VCI distinguish with transmits.Fig. 4 represents the data sending processing flow process and receives handling process.

The data sending processing flow process:

Step 1: extract user cell with the icp cell carrying according to described VPI, VCI value;

Step 2:, and be carried in the icp cell according to the definite hop count that a cell is split of number of links in the group;

Step 3: send described icp cell;

Receive treatment step:

Step 4: extract described icp cell;

Step 5: from described icp cell, extract user data, the user data that extracts is filtered and preserves;

Step 6: filtered data is reverted to user cell.

5 pairs of described user data of described reception treatment step filter, and are that last two overhead bytes that will receive back extraction user data compare, and keep the previous cell in the identical overhead byte cell.

Wherein, step 5 comprises step by step following again in the said method:

Step 11: the capacity of setting is the internal memory of 54 * 128 bytes, can preserve 128 cells, and stipulates the definition of every of first byte, represents whether to receive corresponding section with bit;

Step 12: the user cell of reception deposits described memory field in order in;

Step 13: according to first letter save bit and judge whether a cell collects;

Above-mentioned steps 5 can also comprise step by step following:

Step 21: according to the icp cell number section of setting buffer memory and filtering cache of carrying user cell;

Step 22: extract piecemeal and the user data of more described icp cell; Then repeat this step by step if adjacent segment is identical;

Step 23: preserve new data with described filtering cache, and write in the corresponding section buffer memory after removing two overhead bytes.

Among a kind of embodiment in back, the size of last section buffer memory and front is consistent in described section buffer memory.

Below in conjunction with concrete example receiving course is described:

The one, directly preserve extraction method, its method is: the internal memory of definition 54 * 128 bytes, can store 128 user cells, many bytes are used for filtering, and represent with bit.Preserve in order, as receive first user cell, just be kept at the 54th byte of beginning.As shown in Figure 5, first byte is 00000101, and first of this byte is 1, and expression is received first section, and second is 0, represents second section and does not receive that also the 3rd is 1, and expression is received the 3rd section; Whole byte representation has received the data of first section and the 3rd section.If receive second section again, remove two bytes of expense automatically, be saved in second section, first byte becomes 0X07, represents that a cell is synthetic to finish.After extraction was gone out, first byte just became 0, just can receive the cell of same sequence number.Describe receiving course below in detail:

If first section of receiving first cell, first byte of buffer memory becomes 00000001 by 00000000 so, because the expense of two bytes is arranged when sending, what judge reception according to this expense when therefore receiving is which section of which cell, after judgement finishes, just remove this expense.Simultaneously this segment data is kept at the 2nd to the 19th byte of buffer memory; If second section of receiving first cell, first byte of buffer memory becomes 00000011 by 00000001 so, and second section that will remove expense simultaneously is kept at the 20th to the 37th byte; If second section of at this moment still receiving first cell because first byte 00000011 has represented to have received this section, therefore no longer handled; If the 3rd section of receiving first cell, that is to say, final stage (if a cell only need be divided into three sections), first byte just becomes 00000111 so, the 3rd section of same preservation, if judging first byte is 00000111, just represent that a cell receives (three sections), with the 1st byte clear 0.If what receive is first section of N cell, the 54th * N+1 byte of buffer memory is 00000001 so.Owing to make a start is at first to send first cell, secondly sends out second cell, until 128 cells are sent out first cell then again, circulation repeatedly like this; What receive in receiving end also is first to the 128th cell circulation cell repeatedly naturally.

The 2nd, similar IMA method.As shown in Figure 6, extract user data after, at first filter, just compare,, so just do not carry out any operation if consistent with the one piece of data of receiving previously, if inconsistent, filtering cache is just preserved new data, writes in the corresponding section buffer memory after removing two overhead bytes simultaneously.Be the convenience that reads and writes data, the size of last section buffer memory is consistent with the front, for example, size all is the integral multiple of 18 bytes, that is to say the final stage buffer memory, when writing, write pointer is 18 * N (N represent receive which cell), rather than 17 * N.The section of it should be noted that buffer memory number is a hop count that cell of data is split, therefore section buffer memory number with organize in number of links not necessarily identical, this is and the inconsistent place of ima protocol.In second the different section of being buffer memory all is user data, the content of no icp cell.Another different place is, the read-write of section buffer memory is 18 bytes once, and ima protocol is a cell, 53 bytes.Described section buffer memory is for receiving special definition of user data among the ICP, section buffer memory number is judging that a user cell is just definite when can be carried by several icp cells, that is to say, if a cell needs 3 icp cells to carry, just need 3 sections buffer memorys at receiver section so.

Claims (5)

1. the method for a clog-free transmitting user data in the inverse multiplexing process comprises sending treatment step and reception treatment step, and wherein said transmission treatment step comprises:

Step 1: extract the user cell that carries with inverse multiplexing control protocol cell according to the value of Virtual Path Identifier, virtual path identifiers;

Step 2: determine hop count that a cell is split according to number of links in the inverse multiplexing group, and each section is carried in the inverse multiplexing control protocol cell;

Step 3: send described inverse multiplexing control protocol cell;

Described reception treatment step comprises:

Step 4: extract described inverse multiplexing control protocol cell;

Step 5: from described inverse multiplexing control protocol cell, extract user data, last two overhead bytes that receive back extraction user data are compared, keep the content of the user data of the previous cell in the identical overhead byte cell;

Step 6: filtered data is reverted to user cell.

2. the method for clog-free transmitting user data according to claim 1, it is characterized in that: described step 5 comprises step by step following:

Step 11: the capacity of setting is the internal memory of 54 * 128 bytes, and stipulates the definition of every of first byte;

Step 12: the user cell section of reception deposits described memory field in order in;

Step 13: according to first letter save bit and judge whether a cell collects.

3. the method for clog-free transmitting user data according to claim 2, it is characterized in that: described first byte bit represents whether to receive corresponding section.

4. the method for clog-free transmitting user data according to claim 1, it is characterized in that: described step 5 comprises step by step following:

Step 21: according to the inverse multiplexing control protocol cell number section of setting buffer memory and filtering cache of carrying user cell;

Step 22: extract piecemeal and the user data of more described inverse multiplexing control protocol cell; Then repeat this step by step if adjacent segment is identical;

Step 23: preserve new data with described filtering cache, and write in the corresponding section buffer memory after removing two overhead bytes.

5. the method for clog-free transmitting user data according to claim 4 is characterized in that: the size of last section buffer memory and other section of front is consistent in described section buffer memory.

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