CN105812262A

CN105812262A - Method for realizing efficient data sorting in TCAM with mask management

Info

Publication number: CN105812262A
Application number: CN201610136171.6A
Authority: CN
Inventors: 李占斌; 何志川; 徐文杰; 赵茂聪
Original assignee: Centec Networks Suzhou Co Ltd
Current assignee: Centec Networks Suzhou Co Ltd
Priority date: 2016-03-10
Filing date: 2016-03-10
Publication date: 2016-07-27

Abstract

The invention discloses a method for realizing efficient data sorting in TCAM with mask management, and the method comprises the steps: TCAM is divided into a plurality of blocks according t the mask, and each block is distributed by size in advance or in average according to the arrangement of the routing table; each block comprises a left and a right to indicate the real position of start/end index of the block in TCAM; the internal of each block adopts a internal index management algorithm to acquire the index position, record maximum entry number and current used number of the block, and record which internal indexes are used. The method has an ability of quickly sorting operation functions and maximum move times.

Description

A kind of in the TCAM managed with mask efficient data sequence realize method

Technical field

The present invention relates to a kind of communication technique field, especially relate to a kind of in TCAM manage with mask efficient data sort realize method.

Background technology

In existing network, all of IP forwards and is all based on routing forwarding, and route is that in Software Protocol Stack, common algorithm has fib and trie tree etc. to realize the ability that addressing forwards according to LPM algorithm simultaneously；Owing to LPM algorithm itself does not define a public algorithm, as long as what therefore meet the behavior of LPM algorithm own is all called LPM algorithm.

In ipuc, common TCAM (ternarycontentaddressablememory, three-state content addressing memory, or claim ternary content addressable memorizer) sort algorithm, it is the operation inserted by traveling through key+mask to be then ranked up according to key+mask from the beginning to the end；In this algorithm, the interpolation/deletion each time for route will travel through, and then moves TCAM, causes the waste of substantial amounts of time.

As it is shown in figure 1, in existing routing table, increase the route of an xxx.xxx.xxx.xxx/15:

1, traversal routing table, on the left of Fig. 1, finds mask 16 > 15 > 14 so positions；

2, with reference to routing table, in the middle of Fig. 1, according to the position found, mask is big, all up move a position one by one；

3, with reference to routing table, on the right side of Fig. 1, the route newly increased is added on the position moving out；Delete a routing table and then carry out contrary operating process, move downwards after deletion and become left block from right block；Existing technically, it can be seen that shared chronic of operation, often carry out once-through operation simultaneously, all can carry out substantial amounts of moving number of times；Huge along with routing table, the time of consumption increases therewith.

Summary of the invention

It is an object of the invention to overcome the defect of prior art, it is provided that a kind of in the TCAM managed with mask efficient data sequence realize method.

For achieving the above object, the present invention proposes following technical scheme: a kind of in the TCAM managed with mask efficient data sequence realize method, carry out dividing multiple pieces (block) according to mask (mask) by TCAM in advance, each block distributes the size of block in advance according to the distribution of routing table, or divides equally；Each block has left and right, indicates the index original position in this block and index end position real index original position and index end position in TCAM；Each block is internal adopts inner cable to draw management algorithm, obtains index position, records the maximum entry number of this block simultaneously and has currently used number, and needs to record which internal index and have been used.

Preferably, described TCAM predistribution is that 32 block manage 32 different routes of mask.

Preferably, its method includes normal interpolation when adding route to move, normally add and need upwards to carry out to move, normally add and need to carry out downwards moving three kinds of modes.

Preferably, described normal interpolation theed add when routeing need not be moved, the block of correspondence is obtained according to MASK, by judge in corresponding blocks already with number (used_count) and corresponding blocks in maximum can with how many (max_count), confirm that current block also has position, by indexing one index position of distribution, add and route.

Preferably, described normal interpolation theed add when routeing needs upwards to move, the block of correspondence is obtained according to mask, by judge in corresponding blocks already with number (used_count) and corresponding blocks in maximum can with how many (max_count), confirm that current block does not have position, find previous block, judge also have position, then by obtaining last position of previous block, the left of current block is moved forward a unit, the right of a upper block also moves forward a position, number with max_count, then add and be routed to new position；When previous block is also without resource, then repeat to continue up to borrow, oneself the last item is moved to before by each block, vacant resource is moved current block, to add route, when block0 needs upwards to use resource, find block1 also without, then repeat upwards to use, it has been found that block32 has resource, then the Section Eight territory of oneself is moved on to the 4th region by block31, adjust block32_right, block31_left, then repeats up to move the 13rd region, is finally used in block0 in the 13rd region of block1.

Preferably, the described normally interpolation added when routeing needs the normally interpolation carried out downwards when moving with described interpolation route need not move identical.

Preferably, when previous piece also without resource, then repeating to continue up to borrow, oneself the last item is moved to before, vacant resource is moved current block, in order to add route by each piece.

Preferably, when block0 needs upwards to use resource, find block1 also without, then repeat upwards to use, it has been found that block32 has resource, then the Section Eight territory of oneself is moved on to the 4th region by block31, adjust block32_right, block31_left, then repeats up to move the 13rd region, is finally used in block0 in the 13rd region of block1.

The invention has the beneficial effects as follows: the present invention can rapid pin to this type of with mask management TCAM resource, carry out quick sorting operation；Maximum move the quantity that number of times is block.

Accompanying drawing explanation

Fig. 1 is in existing routing table, increases the schematic diagram of the route of an xxx.xxx.xxx.xxx/15；

Fig. 2 is the schematic diagram that TCAM carries out dividing multiple block in advance according to mask of the present invention；

Fig. 3 is that the present invention adds the schematic diagram being routed to new position on the basis of Fig. 2；

Fig. 4 is that the present invention needs to move the flow chart repeatedly completing a routing operations.

Detailed description of the invention

Below in conjunction with the accompanying drawing of the present invention, the technical scheme of the embodiment of the present invention is carried out clear, complete description.

Shown in Fig. 2, Fig. 3 and Fig. 4, disclosed a kind of in the TCAM managed with mask efficient data sequence realize method, it adopts brand-new LPM sort algorithm, for route with the feature being made without sequence in mask, be that 32 block manage 32 different routes of mask by TCAM predistribution, in this operation, it is possible to reduce route add/delete time move number of times, if even had vacant position, it may not be necessary to move and can complete operation.It is embodied as follows:

Referring again to Fig. 2, in advance TCAM is carried out dividing, according to mask, the size that multiple block, each block can distribute block in advance according to the distribution of routing table, or divide equally；Each block has left and right, indicates start/endindex (index original position and index end position) the real start/endindex position in TCAM of this block；Each block is internal adopts inner cable to draw management algorithm, obtain index position, record the maximum entry number (max_count) of this block simultaneously and currently used number (used_count), and needing to record which internal index and have been used.

When adding route, it is broadly divided into 3 modes:

1, normal interpolation need not be moved: when adding route, according to the MASK block obtaining correspondence, by judging used_count and max_count, confirms that current block also has position, by indexing one index position of distribution, adds and route.

2, need upwards to move: when adding route, the block of correspondence is obtained according to mask, by judging used_count and max_count, confirm that current block does not have position, find previous block, it is judged that also have position, then by obtaining last position of previous block, the left of current block moves forward a unit, and the right of a upper block also moves forward a position, with the number of new max_count；Then add and be routed to new position, be illustrated in fig. 3 shown below；

When previous block is also without resource, then repeat to continue up to borrow, oneself the last item is moved to before by each block, vacant resource is moved current block, to add route, as shown in Figure 4: when block0 needs upwards to use resource, find block1 also without, then repeat upwards to use, find that block32 has resource, then the Section Eight region of oneself is moved on to the 4th region by block31, adjust block32_right, block31_left, then repeat up to move the 13rd region, finally the 13rd region of block1 is used in block0.

Finally adjust then with reference on the right side of Fig. 4；Under maximum case, it is necessary to move 32 times and can complete a routing operations.

3, need to move downwards: similar with upwards moving, be not illustrated herein；In time adding route, additionally use resource not success toward a direction, then use to opposite direction, if all without, then it represents that resource is also full, it does not have vacant position, position issues route.

When deleting route, it is only necessary to delete current location and route, it is not necessary to other operation.

TCAM it be actually a bulk of internal memory, special internal memory. general memory is to look for content. according to address and TCAM is just the opposite, is look for address by Content.In the present invention, adopt TCAM to realize the sequence of Longest prefix match algorithm (LPM) algorithm, there is quick sorting operation function and the maximum ability moving number of times.

The technology contents of the present invention and technical characteristic have revealed that as above; but those of ordinary skill in the art are still potentially based on teachings of the present invention and announcement and do all replacements without departing substantially from spirit of the present invention and modification; therefore; scope should be not limited to the content that embodiment is disclosed; and the various replacement without departing substantially from the present invention and modification should be included, and contained by present patent application claim.

Claims

1. one kind in the TCAM managed with mask efficient data sequence realize method, it is characterised in that: in advance by TCAM according to mask carry out divide multiple pieces, each piece of distribution according to routing table distributes the size of block in advance, or divides equally；Each piece has left and right, indicates the index original position in this block and index end position real index original position and index end position in TCAM；Each block is internal adopts inner cable to draw management algorithm, obtains index position, records the maximum entry number of this block simultaneously and has currently used number, and needs to record which internal index and have been used.

2. according to claim 1 in the TCAM managed with mask efficient data sequence realize method, it is characterised in that described TCAM predistribution is that 32 blocks manage 32 different routes of mask.

3. according to claim 1 in the TCAM managed with mask efficient data sequence realize method, it is characterized in that, its method includes when adding route normal interpolation and need not move, normally add and need upwards to carry out to move, normally add and need to carry out downwards moving three kinds of modes.

4. according to claim 3 in the TCAM managed with mask efficient data sequence realize method, it is characterized in that, described normal interpolation theed add when routeing need not be moved, the block of correspondence is obtained according to mask, by judge in corresponding blocks already with number and corresponding blocks in maximum can with how many, confirm that current block also has position, by indexing one index position of distribution, add and route.

5. according to claim 3 in the TCAM managed with mask efficient data sequence realize method, it is characterized in that, described normal interpolation theed add when routeing needs upwards to move, the block of correspondence is obtained according to mask, by judge in corresponding blocks already with number and corresponding blocks in maximum can with how many, confirm that current block does not have position, find previous piece, judge also have position, then last position by obtaining previous piece, the left of current block is moved forward a unit, the right of a upper block also moves forward a position, with maximum in new corresponding blocks can by the number of how many, then add and be routed to new position.

6. according to claim 3 in the TCAM managed with mask efficient data sequence realize method, it is characterised in that normal during described interpolation route add need to carry out downwards to move with described add route time normal add need not move identical.

7. according to claim 5 in the TCAM managed with mask efficient data sequence realize method, it is characterized in that, when previous piece also without resource, then repeat to continue up to borrow, oneself the last item is moved to before by each piece, vacant resource is moved current block, in order to add route.

8. according to claim 5 in the TCAM managed with mask efficient data sequence realize method, it is characterized in that, when block0 needs upwards to use resource, it has been found that block1 also without, then repeat upwards to use, find that block32 has resource, then the Section Eight territory of oneself is moved on to the 4th region by block31, adjusts block32_right, block31_left, then repeat up to move the 13rd region, finally the 13rd region of block1 is used in block0.