CN101330512B - Protocol speed-accelerating device - Google Patents
Protocol speed-accelerating device Download PDFInfo
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- CN101330512B CN101330512B CN2008101451455A CN200810145145A CN101330512B CN 101330512 B CN101330512 B CN 101330512B CN 2008101451455 A CN2008101451455 A CN 2008101451455A CN 200810145145 A CN200810145145 A CN 200810145145A CN 101330512 B CN101330512 B CN 101330512B
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Abstract
The invention provides a routing table generating unit that generates a routing table describing a next hop to which a packet is to be sent according to a destination address of the packet that is input via an input channel, including a ternary content addressable memory (TCAM); an external memory; a unit that classifies items in information that is received; and a unit that stores an item that uniquely identifies the information among the classified items in the TCAM and stores the rest of the items to the external memory.
Description
Technical field
The present invention relates to a kind of generation technique of routing table, OSPF) and ISIS Routing Protocols such as (IntermediateSystem to Intermediate System: intermediary system are to intermediary's system protocol) be used for: use OSPF (OpenShortest Path First:, between the packet transfer device in network or between the routing table generating device to the packet transfer device information on the network, the network information exchanges, receive, and use according to this exchange, the information that receives is calculated the shortest path firsts such as Dijkstra of shortest path, asks for the shortest path of the target that arrives bag.
The present invention is used for packet transfer device such as ip router to carry out the interface of necessary processing the (for example see destination address, obtain the shortest path that arrives target, with the outlet line that determines this bag etc.) from the bag of incoming line input.Particularly, relate to and utilize OSPF (Open ShortestPast First) and the ISIS controlling packet that Routing Protocol received such as (Intermediate System to Intermediate System) to handle the technology of received information use.
Background technology
The present invention statement is willing to 2003-296408 number for the spy in application on August 20th, 2003 and the spy of application on August 22nd, 2003 is willing to the priority of 2003-298734, and with its content in this refers to the present invention.
In the past, routing table generating device only is to be made of external memory storage (SRAM and SDRAM) and information processor, information processor is classified to received information according to each of information, afterwards, item according to unique identifying information generates search tree, in the tree stored received information and tree structure information.
Routing Protocol such as OSPF and ISIS is used for carrying out the exchange of control messages between packet transfer devices such as router, based on the link cost information of the packet transfer device on the resulting network, derive shortest path.Control messages be when the renewal that network state takes place or (and) termly the packet transfer device of all in network broadcast.
In order to judge whether the control when the router receiving control message is new, need (retrieve the link state database that utilizes control messages to produce hereinafter referred to as LSDB (Link State DateBase: LSD)), but, in existing mode, the LSDB retrieval is that the route control device at the control Routing Protocol (is concentrated in hereinafter referred to as RS (Route Server: routing server)) and carried out.
Memory access rate becomes key in the LSDB retrieval rate, but in most of packet transfer devices, for cutting down cost, mostly personal computer card is used as RS, they have adopted slow memory, therefore, and both just under the situation of not using personal computer card, also since in RS operation various application programs or OS etc., thereby adopted the slow memory cheaply that requires mass storage.For this reason, can not carry out the high speed retrieval of LSDB.
In the past, in the LSDB retrieval that utilizes RS, produce search tree and carry out retrieval.RS classifies to the information of the controlling packet of coming from interface transmission according to each, and with unique this information of identification be that the basis generates search tree, in tree, stored received information and tree structure information.
Below will in search tree the Pa Telixia of general use tree (Patricia tree) describe.Pa Telixia tree is a kind of 2 fork search trees, use pointer with node link to tree.
Fig. 1 is illustrated in the figure that should retrieve comparison item and its answer that shows in the key.Fig. 2 represents to use Pa Telixia to set and retrieves the example of the key of Fig. 1.In order easily to understand invention, be 5 bits by the length setting of the represented field of 2 system numbers with each field." * " neglects bit value thereafter when being illustrated in retrieval.
The search key of corresponding retrieval compares with the comparison item that is stored on the node on one side, will set to inferior division on one side.When the search key that should retrieve arrived certain node, the high position of comparison item of holding from this node and the search key that should retrieve began position to necessity and compares (until the position before the *, if 100* then is high 3) and retrieve.Under inconsistent situation, do not finish retrieval there to be consistent result.Under the situation of unanimity, then pay close attention in the search key that should retrieve next bit through the last position of relatively position, when existing, move to child node and proceed to retrieve than oneself also low node (hereinafter referred to as child node).The moment all consistent at all bits stops retrieval, can obtain to be stored in the answer on this node.
In Fig. 2, shown the example when retrieving 10001 these search keys.At first, check begin most 1 of search key and judge that it is 0 or 1.In this example, owing to be 1, therefore, move to node 100*, than higher 3.Owing to be consistent, therefore, next investigation is become the 4th of the search key of checking the position.Because retrieval position is 0 therefore to move to node 10001.Here,, therefore stop retrieval, can access as the X that answers because all positions are all consistent.
In addition, use TCAM (Ternary Content Addressable Memory: the search method ternary content addressable memory) in addition.TCAM is used for the routing table retrieval on the interface sometimes.TCAM is that the data of being stored exported in keyword with the physical address unlike SRAM and SDRAM etc., but will be stored in the value in each physical address and the value imported compares, and under the situation of unanimity, the physical address of homogeneity value has been stored in output.
Represented among Fig. 3 to use TCAM to retrieve the example of the key of Fig. 1.In the TCAM stored relatively, externally store memory has stored up its answer.At this moment, the physical address of the external memory storage of the answer of item can mate with having stored relatively to make the physical address of having stored the TCAM that compares item.In this example, the physical address of the TCAM that has stored relatively and the physical address of external memory storage of having stored the answer of comparison item are considered as identical physical address.
As mentioned above, TCAM compares value and the input value that is stored in each physical address, under the situation of unanimity, the physical address of homogeneity value has been stored in output, therefore, in the example of Fig. 3, at 10001 o'clock that have imported as search key, output physical address #9, thus can serve as that the basis obtains answer from external memory storage with this physical address.The retrieval of TCAM is 1 input, owing to can retrieve all data of being stored 1 time, therefore, can carry out the very retrieval of high speed, and it retrieves the also immovable advantage of required time even if having network change big (both just relatively a change was many).
The degree of depth of tree depends on the bit width of the search key that should retrieve.For example, search key is if the IPv4 address, and then maximum demand is 33 times, if Ipv6 address maximum demand 129 times then.Fig. 4 is represented by dotted lines the searching route of having used the Pa Telixia tree.Because the information stores of intranodal is in external memory storage, therefore, the retrieval number of times is directly proportional with the memory reference number of times.If it is big that the bit wide of search key becomes, then the node number of tree increases, and retrieval number of times (memory reference number of times) increases, thereby the problem of retrieval a lot of times of needs occurred.
Processing for carrying out the Routing Protocol that generates routing table roughly is divided into following 3 kinds:
(1) linking status information management: carry out the transmitting-receiving of linking status packets of information such as passing on link and network state, linking status information is managed as database;
(2) shortest path calculates: by means of the linking status database of information, utilize such as shortest path firsts such as dijkstra's algorithms, calculate the shortest path that arrives target;
(3) discovery of neighboring router and keep (Hello wraps processing): Hello wraps discovery and the fault detect of carrying out neighboring router by exchange.
Particularly, both just in processing as (1) that needs a lot of processing times, (2), the time that is spent in the retrieval of linking status information database accounts for a lot, in existing mode, because use search tree, and make the interstitial content of the big more tree of network big more, so the database of retrieval link state information needs spended time.For this reason, along with popularizing fast of internet in recent years, the network of a management domain management is just becoming increasing, and accompany therewith, the generation that has produced routing table is slack-off, and the problem of (flapping) (shortest path does not have unique definite, and it is indefinite to drift about) is played pendulum in the path, existence (for example, please refer to Faster link-state IGP convergence and improved networkscalability and stability with the problem that a management domain can not make macroreticular; Choudhury, G.L.; Maunder, A.S.; Sapozhnikova, V.D.; Local Computer Networks, 2002.Proceedings.LCN2001.26th Annual IEEE Conference on, 14-16 Nov.2001.Page (s): 149-158).
Summary of the invention
The 1st mode of the present invention is made under above-mentioned background, and its purpose is to solve owing to the increase that is accompanied by network causes generating routing table needs spended time, and can not be in the problem of making macroreticular with a management domain.
The 1st mode of the present invention is a kind of routing table generation device, and it is based on the destination address from the bag of incoming line input, produces the routing table of the next distance section (hop) that is used to determine this bag.
Wherein, the 1st mode of the present invention is characterised in that to have: TCAM, external memory storage, be stored in the described TCAM according to every unit that the information that is received is classified and with the item of unique this information of identification in this item that is classified and other is stored in unit in the described external memory storage.
Thus, when the information of retrieve stored,, therefore, can realize retrieval at a high speed owing to can only retrieve the TCAM of the item that has been stored unique this information of identification.
The present invention can have: when newly having received information, before this information of storage, with the described item that is classified unique this information of identification in the item as search key, the unit of the information of retrieve stored in described TCAM; Utilize this retrieval, when described unique identification item of new reception information and the described unique identification item that has been stored in the information in the described TCAM are inconsistent, start the unit of the stores processor of the unit of described execution storage carrying out; And, passing through this retrieval, described unique identification item of new reception information and be stored in described unique identification item of the information in the described TCAM when consistent carries out new and old ratio than the unit to same item corresponding with this unique identification item, that be stored in information and the information of new reception in the described external memory storage.
In addition, the present invention can have: utilize the comparative result of described execution unit relatively, when new reception information is old or more identical than the information in the described external memory storage of being stored in, ignore the unit of the information of this new reception; And, utilize described execution than comparative result than the unit, when the new information that receives is newer than the information in the described external memory storage of being stored in, the unit that utilizes the new information that receives that the information that is stored in the described external memory storage is upgraded.
Thus, when newly arrived information is old or more identical than the information in the external memory storage of being stored in, does not carry out to upgrade and handle, this can alleviate required processing burden in the renewal processing, simultaneously, can also avoid the storage of unnecessary information, effectively utilize memory.
The present invention can have: use the information that is stored in described TCAM and the described external memory storage, based on the target location of the bag that arrives, carry out the unit of Shortest Path Searching.
Thus, can use the information processor of 1 device to carry out the generation and the Shortest Path Searching of routing table simultaneously, and can effectively utilize hardware.
In addition, can also have, decide the unit of next distance section of the bag of arrival based on described Shortest Path Searching.
Another viewpoint of the present invention's first mode is a kind of like this program, and it can be applied to following routing table generating device: based on the destination address from the bag of incoming line input, produce the routing table of the next distance section that is used to determine this bag.
Wherein, the present invention's the 1st mode is characterised in that: by being installed on the computer installation, thereby realize following function on this computer installation: according to every function that the information that is received is classified; And, with being stored in the TCAM of unique this information of identification in this item that is classified, other are stored in the external memory storage.
The present invention can carry out following function: when newly having received information, before this information of storage, what be classified unique this information of identification in the item is search key with described, comes the information of retrieve stored in described TCAM; Utilize this retrieval, at described unique identification item of new reception information be stored in described unique identification item of the information in the described TCAM when inconsistent, start the stores processor that function that described execution stores is carried out; And by retrieval, at described unique identification item of new reception information with the item of described unique identification of the information in being stored in described TCAM when consistent, to carrying out new and old comparison with the new identical entry of reception information with the corresponding information that is stored in the described external memory storage of the item of this unique identification.
In addition, the present invention can realize following function: according to the comparative result of described execution function relatively, when new reception information is old or more identical than the information in the described external memory storage of being stored in, ignore the information of this new reception; And, when new reception information is newer than the information in the described external memory storage of being stored in, utilize the new information that receives that the information that is stored in the described external memory storage is upgraded according to the comparative result of described execution function relatively.
The present invention can realize following function: use the information that is stored in described TCAM and the described external memory storage, based on the destination address of the bag that arrives, carry out the function of shortest path exploration.In addition, can realize following function: explore based on described shortest path, decide the next distance section of the bag of arrival.
Another viewpoint of the present invention's the 1st mode provides a kind of recording medium, can be read by the described computer installation that has write down program of the present invention.Because program of the present invention is recorded on the recording medium of the present invention, thereby described computer installation can use this recording medium that program of the present invention is installed.Perhaps also can be directly program of the present invention to be installed on the described computer installation from the server of holding program of the present invention via network.
Thus, can realize following this routing table generating device: use the general calculation machine can shorten the rise time of routing table, thereby produce macroreticular with a management domain.
The present invention's the 2nd mode is a kind of LSDB indexing unit, and this device is installed in packet forwarding apparatus, and is arranged at carrying out in the interface of handling from the bag of incoming line input.The characteristic point of the present invention's the 2nd mode is, comprises: use the controlling packet of Routing Protocol to collect the unit of the information that is received; Store the unit of at least a portion item of the reception information of this collection; And the unit institute that this canned data and described execution are collected newly the information of at least a portion item of reception information compare, with the unit of judging that this information is new and old.Thus, can judge the new and old of the information that arrives.
Above-mentioned LSDB indexing unit can have with lower unit: the judged result of the unit of judging based on described execution, in the information of at least a portion item of described new reception information is during newly in the information of described canned data, transmit newly arrived controlling packet with described new reception information to route control device, in the information of at least a portion item of described new reception information and described canned data is equal or during old information, discarded unit with newly arrived controlling packet of described new reception information.
Thus, owing to can select fresh information, and only this fresh information is handled, therefore, can cut down the burden of RS, be macroreticular impossible, a territory management thereby can make former.
Or, above-mentioned LSDB indexing unit can have: the judged result of the unit of judging based on described execution, in the information of at least a portion item of described new reception information is during newly in the information of described canned data, and the LSDB indexing unit in other interfaces transmits the unit of information of at least a portion item of the controlling packet that has been sent to described route control device.
Above-mentioned LSDB indexing unit has the judged result of the unit of judging based on described execution, in the information of at least a portion item of described new reception information is during newly in the information of described canned data, and the LSDB indexing unit in other interfaces transmits the unit of information of at least a portion item of the newly arrived controlling packet with described new reception information; It can also have the unit of the information of at least a portion item that is used to store the described controlling packet that sends from other devices.
Thus, can select fresh information, and only to make these fresh informations be that a plurality of LSDB indexing units are common.
Another viewpoint of the present invention's the 2nd mode is a kind of program that is applied to following LSDB indexing unit, and described LSDB indexing unit is installed in the packet transfer device, and is arranged at carrying out in the interface of handling from the bag of incoming line input.Characteristic point of the present invention is, by it is installed in the computer installation, can make this computer installation realize having the pairing function of LSDB indexing unit of following function: to use the controlling packet of Routing Protocol to collect the information that receives; Store at least a portion item of this reception information of collecting; And with this canned data and the function of utilizing described execution to collect newly receive at least a portion item of information information compare, judge that afterwards this information is new and old.
The present invention can realize following function: the judged result of the function of judging based on described execution, in the information of at least a portion item of described new reception information is during newly in the information of described canned data, transmit newly arrived controlling packet with described new reception information to route control device, in the information of at least a portion item of described new reception information and described canned data is equal or during old information, discarded have a described newly arrived controlling packet that newly receives information.
The present invention can realize following function: the judged result of the function of judging based on described execution, in the information of at least a portion item of described new reception information is during newly in the information of described canned data, and the LSDB indexing unit in other interfaces transmits the information of at least a portion item of the controlling packet that has been sent to described route control device.
The present invention can realize following function: the judged result of the function of judging based on described execution, in the information of at least a portion item of described new reception information is during newly in the information of described canned data, and the LSDB indexing unit in other interfaces transmits the information of at least a portion item of the newly arrived controlling packet with described new reception information.The present invention can also realize being used to storing the function of information of at least a portion item of the described controlling packet that sends from other devices.
In addition, another viewpoint of the present invention's the 2nd mode is a kind of recording medium that program of the present invention, described computer installation can read that write down.By program of the present invention is recorded on the recording medium of the present invention, thereby described computer installation can use this recording medium that program of the present invention is installed.Or, also can program of the present invention directly be installed on the described computer installation from the server of holding program of the present invention via network.
Thus, use the general-purpose computations machine to cut down the processing burden of the RS in the packet transfer device, thereby can realize making the LSDB indexing unit of macroreticular with a management domain.
Description of drawings
Fig. 1 illustrates the example of existing search list.
Fig. 2 is the figure that is used to illustrate the search method of utilizing existing Pa Telixia tree.
Fig. 3 is used to illustrate the figure that uses existing TCAM to retrieve.
Fig. 4 illustrates the searching route of using the Pa Telixia tree.
Fig. 5 is the structure chart of the routing table generating device of the present invention's the 1st execution mode.
Fig. 6 is the structure chart of the packet transfer device that existed.
Fig. 7 illustrates the structure example 1 of the packet transfer device of the present invention's the 1st execution mode.
Fig. 8 illustrates the structure example 2 of the packet transfer device of the present invention's the 1st execution mode.
Fig. 9 illustrates the structure example 3 of the packet transfer device of the present invention's the 1st execution mode.
Figure 10 illustrates the structure example 4 of the packet transfer device of the present invention's the 1st execution mode.
Figure 11 illustrates the form of Router LSA.
Figure 12 illustrates the form of Network LSA.
Figure 13 illustrates the network operating example of the information processor that is used to illustrate the present invention's the 1st execution mode.
Figure 14 illustrates the TCAM that stores the present invention the 1st embodiment into and the Storage Item of external memory storage.
Figure 15 is the figure of the LSA that is used to illustrate the present invention's the 1st execution mode operation when receiving.
Figure 16 is the figure of the SPF that is used to illustrate the present invention's the 1st execution mode operation when calculating.
Figure 17 illustrates the search modes of the present invention's the 1st execution mode.
Figure 18 is a curve chart, and its expression utilizes the resulting analog result of the search modes of Figure 17.
Figure 19 is the structure chart of packet transfer device of LSDB indexing unit with the 1st embodiment of the present invention's the 2nd execution mode.
Figure 20 is the structure chart of LSDB indexing unit of the 1st embodiment of the present invention's the 2nd execution mode.
Figure 21 is the structure chart of packet transfer device of LSDB indexing unit with the 2nd embodiment of the present invention's the 2nd execution mode.
Figure 22 is the structure chart of LSDB indexing unit of the 2nd embodiment of the present invention's the 2nd execution mode.
Figure 23 illustrates a kind of of the LSA that write down packet transfer device information, the i.e. form of Router LSA.
Figure 24 illustrates a kind of of the LSA that write down the network information, the i.e. form of Network LSA.
Figure 25 illustrates the network example that is used to illustrate the operational example that is stored in interior information of LSDB rope device and information processor.
Figure 26 illustrate based on Figure 25, be stored in the information in the LSDB indexing unit.
Example of operation when Figure 27 illustrates the LSDB indexing unit and received LSA.
Figure 28 illustrates the structure example 1 of the packet transfer device that has existed.
Figure 29 illustrates the structure example 2 of the packet transfer device that has existed.
Embodiment
Below, with reference to the accompanying drawings preferred forms of the present invention is described.But the present invention is not limited in following each embodiment, for example, and structural element that also can these embodiment of appropriate combination.
＜the 1 execution mode 〉
The 1st execution mode of the present invention relates to routing table generating device, below, with reference to Fig. 5 to Figure 16 this routing table generating device is described.Fig. 5 is the structure chart of the routing table generating device of the present invention's the 1st execution mode.
The 1st execution mode of the present invention is a kind of route generating apparatus, and it is based on the destination address from the bag of incoming line input, produces the routing table of the next distance section that is used to determine this bag.
Wherein, the 1st execution mode of the present invention is characterised in that as shown in Figure 5, have TCAM101 and external memory storage 102, comprises in information processor 103: by every unit that received information is classified; This is classified being stored in the described TCAM of unique this information of identification in the item, other are stored in unit in the described external memory storage.
In addition, information processor 103 has: utilize the comparative result of described execution unit relatively, the new information that receives old in being stored in external memory storage 102 information or when identical with it, ignore the unit of this information that newly receives; And the comparative result that utilizes described execution unit relatively, newly during the information in being stored in external memory storage 102 in, utilize the new information that receives in the new information that receives to being stored in the unit that external memory storage 102 interior information are upgraded.
The 1st execution mode of the present invention can be by being installed in the general-purpose computations machine, thereby can be as making this computer installation realize realizing with the corresponding functional programs in each unit of routing table generating device of the present invention.This program is recorded on the recording medium and is installed in the computer installation, or by being installed on the computer via communication line, thereby this computer can be realized and information processor 103 function corresponding.
Below, further describe the 1st execution mode of the present invention.
As shown in Figure 5, the routing table generating device of present embodiment has information processor 103 and TCAM 101 and external memory storage 102.Information processor 103 is according to every of information, to using Routing Protocols such as OSPF or ISIS to come the information that exchange is collected is classified, with being stored in the TCAM1 of unique identifying information, with in addition required (hereinafter referred to as linking status information) separate storage externally in the memory 102; From received information, extract the item that is used for unique identifying information, and be entered in the TCAM 101, carry out retrieval afterwards, information stores is arrived in the external memory storage 102 according to this result; Carry out information updating, thereby carry out necessary processing.Information processor 103 has the TCAM of utilization 101 and external memory storage 102 calculates shortest path, and transmits the function of routing table to the routing table indexing unit.
Fig. 6 is the structure example of existing packet transfer device.By RS (Route Server, routing server) 120 SW (Switch,, switch) 130 IF (Interface: circuit) constitute,, utilize RS 120 to carry out the processing of Routing Protocols such as OSPF and ISIS, generate routing table, afterwards, the routing table that will make in RS 120 is sent to IF routing table indexing unit 110.
Wrap in NP (Network Processor: network processing unit) extract destination address 111 from incoming line input, in routing table indexing unit 110, decide next distance section (next router) based on the shortest path that arrives target, thus the IF of decision output packet.
Below, explanation is had 4 examples of packet transfer device structure of the routing table generating device of the present invention's the 1st execution mode.
(structure example 1)
Fig. 7 represents the structure example 1 of the routing table generating device of the present invention's the 1st execution mode.Structure example 1 has disposed the routing table generating device 122 of present embodiment in RS121.This is a kind ofly to carry out in RS121 for the processing that makes Routing Protocols such as OSPF or ISIS, and will utilize the routing table generating device 122 of this information to place structure in the RS121.Therefore this structure, has the advantage of exchange necessary information in routing table generating device 122 easily because routing table generating device 122 is placed in the RS121.
(structure example 2)
Fig. 8 represents the structure example 2 of the routing table generating device of the present invention's the 1st execution mode.Structure example 2 has been equipped with routing table generating device 112 on I F.Because the routing table that routing table generating device 112 is generated is sent to routing table indexing unit 110, therefore, has its transmission and be easy to advantage.
(structure example 3)
Fig. 9 represents the structure example 3 of the routing table generating device of present embodiment.This structure example is the structure example of only having appended a TCAM 101 to RS 123.RS123 has CPU 124 suitable with the information processor 103 of the routing table generating device of present embodiment shown in Figure 5 and the external memory storage 125 suitable with external memory storage 102.Be used as information processor 103 by the CPU124 that will be had, and newly append external memory storage 125 and the TCAM 126 that is had, can generate routing table generating device 127.This example has been owing to utilized CPU 124 and the external memory storage 125 that is had, thereby has the advantage of finishing with less cost.
(structure example 4)
Figure 10 represents the structure example 4 of the routing table generating device of present embodiment.NP111 has functional processor, it is used as information processor shown in Figure 5 103, by the TCAM 114 that will be disposed for routing table indexing unit 116 and external memory storage 115 as TCAM 101 and external memory storage 102 shown in Figure 5, thereby can make routing table generating device.Therefore this example, has the advantage of finishing with less cost owing to used interior processor and external memory storage 115 and the TCAM 114 of NP111 that is had.
(structure example 5)
Following as Routing Protocol, will with OSPF example, describe with regard to the information of TCAM 101 and external memory storage 102 stored and the operation of information processor 103.Under the OSPF condition, in the packet transfer device information on the networking and the network information between the packet transfer device in network or between the routing table generating device, (Link State Update: the bag linking status upgrading) is carried out exchange to the information that the OSPF exchange is collected, and exists 5 kinds to be called as LSA (Link State Advertisement: the data class linking status announcement), that be used to describe the packet transfer device or the network information in LSU according to being called as LSU.
Figure 11 has represented to record and narrate a kind of LSA of packet transfer device information, the i.e. form of Router LSA.A kind of LSA that Figure 12 has represented to record and narrate the network information is the form of Network LSA.The network example that Figure 13 represents to be stored in information in TCAM and the external memory storage, carries before the operational example of information processor as an illustration.With regard to as based on the collection of Figure 13 the LSDB of LSA database of information (Link State Date Base: link state database), Figure 14 represents to be stored in TCAM and the interior information of external memory storage.
LSA is owing to come unique identification by LS Type, Link State ID, Advertising Router, therefore, they is stored in the TCAM item as unique knowledge information, with in addition item as the linking status information stores externally in the memory.
Operational example when Figure 15 represents routing table generating device reception LSA.When receiving LSA, according to the LS Type of the LSA that receives, Link State ID, Advertising Router judge that free of data is arranged in TCAM.If in TCAM, do not have, then owing to become new LSA, therefore, be appended in the LSDB (be divided into TCAM and external memory storage comes stored information).Exist in LSDB under the data conditions, owing to (hit) occurred hitting in TCAM, therefore draw information from external memory storage, afterwards, that carries out Sequence Number etc. relatively waits necessary processing.
In the example of Figure 15, establish the Router LSA of packet transfer device A reception from packet transfer device D.Owing under this routine situation, occurred among the TCAM hitting, therefore, draw information from external memory storage, that carries out Sequence Number etc. relatively waits necessary processing.
So-called necessary processing for example is: the Sequence number of the LSA that received and the Sequence number that has been stored in the information in the external memory storage are compared; According to this comparative result, the new LSA that receives old in be stored in the external memory storage information or when identical, ignore the LSA of this new reception; According to this comparative result, during newly in the information that is stored in the external memory storage, utilize the new LSA that receives that the information that is stored in the external memory storage is upgraded at the new LSA that receives.
In Figure 16, represented the example that router-A execution shortest path calculates.Utilize following step can obtain network configuration information.Can use dijkstra's algorithm to obtain shortest path according to network configuration information.
Step 1: DR (Designated Router) address of asking for network according to the Link State ID that calculates source router.
Step 4,5: the address with Attached Router is a keyword, obtains the information (the IP address of link, measure (metrics) etc.) of Attached Router according to Router LSA.Thus, the clear and definite link information of router, thus determined the router of next distance section.
Assess effect of the present invention according to following condition.Suppose to replace with from the local former state that OSPF calls retrieval functions (establish search method be Pa Telixia tree) TCAM is conducted interviews, compare according to the Pa Telixia tree of Figure 17 and the simple retrieval pattern of TCAM.Retrieval rate is to be reference with the access speed of SRAM that buys in easily in the commercialization and TCAM (each 5ns).The CPU processing time, under the situation of Pa Telixia tree retrieval, when carrying out primary retrieval, just must begin retrieve data one by one from the high position of tree, and under the situation of TCAM retrieval, it all only is that data are inputed to TCAM that CPU handles, therefore, and clearly, still Pa Telixia sets more spended time of retrieval mode, but it at the row of consideration, is not only assessed by memory access time specifically.Sending under the situation of 10000 LSA, at the situation of utilizing the Pa Telixia tree to retrieve with utilize each LSA under the situation that TCAM retrieves to calculate and predict the outcome retrieval time to be illustrated in Figure 18.Access times are many more, and then the access time difference of Pa Telixia tree and TCAM is big more, and final, we can see that total access time of TCAM becomes Pa Telixia and sets about 1/6 of total access time.
As mentioned above,, can shorten the rise time of routing table, can make big network with a management domain according to the 1st execution mode of the present invention.
＜the 2 execution mode 〉
The 2nd execution mode of the present invention is a kind of LSDB indexing unit.Below, to Figure 22 this LSDB indexing unit is described with reference to Figure 19.Figure 19 is the structure chart of packet transfer device of LSDB indexing unit with the 1st embodiment of the present invention's the 2nd execution mode.Figure 20 is the structure chart of LSDB indexing unit of the 1st embodiment of the present invention's the 2nd execution mode.Figure 21 is the structure chart of packet forwarding apparatus of LSDB indexing unit with the 2nd embodiment of the present invention's the 2nd execution mode.Figure 22 is the structure chart of LSDB indexing unit of the 2nd embodiment of the present invention's the 2nd execution mode.
As shown in figure 19, the 2nd execution mode of the present invention is a kind of LSDB indexing unit 210, and it is installed in the packet forwarding apparatus 230, and is arranged at carrying out in the interface of handling from the bag of incoming line input.As shown in figure 20, present embodiment is characterised in that, comprises: use the controlling packet of Routing Protocol to collect the information processor 201 of received information; And the high speed external memory storage 202 that at least a portion item of this reception information of collecting is stored.The information that information processor 201 has at least a portion item of the information that is stored in the information in the high speed external memory storage 202 and newly receives compares, and judges the new and old unit of this information.
The present invention as by being installed on the general-purpose computations machine, thereby making this computer installation realize functional programs corresponding with LSDB indexing unit of the present invention and realizes.This program is recorded on the recording medium, and is installed in the computer installation, or, by it being installed on the computer installation, thereby this computer installation is carried out and information processor 201 corresponding functions via communication line.
Packet transfer device shown in Figure 21 has LSDB indexing unit shown in Figure 22.In the packet transfer device shown in Figure 21, routing table indexing unit and LSDB indexing unit are realized as a LSDB indexing unit 211.
(the 1st embodiment)
Figure 20 illustrates the LSDB indexing unit example of the 1st embodiment of the present invention's the 2nd execution mode.The LSDB indexing unit 210 of the 1st embodiment shown in Figure 19 has information processor 201 and high speed external memory storage 202.In the present embodiment, in the retrieval of LSDB, use Pa Telixia to set this tree search.Owing to utilize the part item of the controlling packet that LSDB indexing unit 210 received to be transmitted to RS 220, therefore, information processor 201 is classified to the information that receives according to every, item with unique this information of identification is that the basis makes search tree, and storage is used to judge item, the tree structure information of unique this information of identification and judges the new and old information (hereinafter referred to as LS sequence number) of control messages in tree.
After the part item of the controlling packet that receives from interface was stored in the LSDB indexing unit 210, the part item of the controlling packet that LSDB indexing unit 210 will have been stored sent other interfaces to.Have, the part of the controlling packet that other interfaces are received is transferred in the LSDB indexing unit 210 via the LSDB indexing unit of other interfaces again.Thus, in the LSDB of each interface indexing unit 210, can shared up-to-date information.
When having imported the controlling packet of Routing Protocols such as OSPF and ISIS from incoming line, information processor 201 takes out the item and the LSsequence number of unique identifying information from the item of information of controlling packet, and utilizes search tree to carry out retrieval.The item of having imported the information in the controlling packet that unique identification imports as a comparison after, carry out retrieval.The result of retrieval, when having found answer, compare to the LS sequence number of the controlling packet imported and as the LS sequence number that is stored in the tree that answers, information in the controlling packet of being imported is under the situation of non-new (identical with the information that has received or older) information, discarded this controlling packet.At comparative result is under the news, transmits this controlling packet to RS.
At comparative result is under the news, in the LSDB of the interface that has received controlling packet indexing unit 210 storage unique this controlling packet of identification information the item and LS sequence number, and with unique this information of identification the item be that the basis makes search tree.Afterwards, this LSDB indexing unit 210 transmits the item and the LS sequence number of the information of unique this controlling packet of identification to the total interface outside interface.The item and the LS sequence number of the information of the controlling packet that the unique identification of LSDB indexing unit 210 storage sends from other interfaces.Thus, in the LSDB of each interface device 210, can shared up-to-date information.
(the 2nd embodiment)
Figure 22 illustrates the LSDB indexing unit of the 2nd embodiment of the present invention's the 2nd execution mode.The LSDB indexing unit 211 of the 2nd embodiment has information processor 201, TCAM 203 and high speed external memory storage 202.In the 2nd embodiment, that utilize in the retrieval of LSDB is TCAM 203.Owing to will utilize the part item of the received controlling packet of LSDB indexing unit 211 to send RS 220 to, therefore, information processor 201 is classified to the information that receives according to every, and, the new and old LS sequence number that judges control messages is stored in the high speed external memory storage 202 being stored in the TCAM 203 of unique this information of identification.
The result of retrieval, when having found answer, compare to the LS sequencenumber of the controlling packet imported with as the LS sequencenumber that are stored in the high speed external memory storage 202 that answer, information in the controlling packet of being imported is under the situation of non-new (identical with the information that has received or older) information, discarded this controlling packet.At comparative result is under the news, transmits this controlling packet to RS220.
At comparative result is under the news, has received the item and the LS sequence number of information of unique this controlling packet of identification of LSDB indexing unit 211 storage of the interface of controlling packet, and is that the basis makes search tree with unique this information of identification.Afterwards, LSDB indexing unit 211 transmits the item and the LSsequence number of the information of unique this controlling packet of identification to the total interface beyond its own interfaces.The item and the LS sequence number of the information of the controlling packet that the unique identification of LSDB indexing unit 211 storage sends from other interfaces.Thus, in the LSDB of each interface indexing unit 211, can have up-to-date information.
(the 3rd embodiment)
Below, as Routing Protocol, be example with OSPF, describe being stored in the information in the LSDB indexing unit and the operation of information processor.Under OSPF, the information that between the packet forwarding apparatus information on the network or between the routing table generating device packet transfer device information on the network and the network information is exchanged collection is carried out exchange according to the bag that is called LSU (Link State Update), exists 5 kinds to be called as data class LSA (Link StateAdvertisement), that describe the packet transfer device or the network information on LSU.
Figure 23 represent as recorded and narrated packet transfer device information, as the form of a kind of Router LSA of LSA.Figure 24 represented to record and narrate the network information, as the form of a kind of Network LSA of LSA.Figure 25 represents to be used to illustrate the network example of the operational example that is stored in interior information of LSDB indexing unit and information processor.Figure 26 represents to be stored in the information based in the LSDB indexing unit of Figure 25.LSA is owing to come unique identification by means of LS Type, Link StateID, Advertising Router, therefore, is stored in the LSDB indexing unit as the item of unique these information of identification.Owing in order to judge the new and old of LSA LS sequence number, LS checksum, LS age must be arranged, therefore, they are stored in the LSDB indexing unit as LS sequence number.Operational example when Figure 27 represents that the LSDB indexing unit has received LSA.When receiving LSA, be search key with LS Type, Link State ID, the Advertising Router of the LSA that received, utilize the LSDB indexing unit to judge that LSA's is new and old.
(1)～(6) determining step of representing new and old LSA.
(1) having greatly, the LSA of LS sequence number is up-to-date;
(2) under the identical situation of sequence number, the LSA with big LS checksum is up-to-date;
(3) under the also identical situation of LS checksum, up-to-date as the LSA of the LS age of MAX Age;
(4) be not under the situation of Max Age at any one LSA, if the difference of LS age is more than or equal to Max Age Diff (15 minutes), the LSA that then has less LS age is up-to-date;
(5) as if what in (1)～(4), just in time be fit to, then regard identical LSA as;
(6) discarded all LSA (comprising identical LSA) outside up-to-date, up-to-date LSA is sent to RS, and Here it is by the determining step of the new and old LSA of OSPF defined.
Below, the structure example when just the LSDB indexing unit of present embodiment being installed on packet transfer device describes.
(structure example 1)
Figure 28 is the structure example 1 of existing packet transfer device.The packet transfer device rude classification, it has RS (Router Server, routing server) 220, SW (Switch, exchange) 240, IF (Interface: interface).Carry out the processing of Routing Protocols such as OSPF and ISIS in RS 220, produce routing table, afterwards, the routing table that will generate in RS 220 is sent to IF routing table indexing unit 215.Wrap in NP (Network Processor from incoming line input, network processing unit) extracts target address information in, in routing table indexing unit 215, decide next distance section (next router) based on the shortest path that arrives target, thereby determined the IF of output packet.
The structure example 1 of the existing packet transfer device of Figure 28 is used search tree in routing table indexing unit 215.Owing in routing table indexing unit 215, only need routing table, therefore, can finish with lacking a lot of capacity than the needed memory of RS220.For this reason, can utilize the high speed external memory storage, can also be than the tree search more speed ground search tree of using the low speed external memory storage.
(structure example 2)
Figure 29 is the structure example 2 of existing packet transfer device.Be to have used TCAM in the routing table indexing unit 216 with structure example 1 difference.Because needing bag more at a high speed to transmit in the capacity core router greatly, therefore, in the routing table retrieval, general using can be carried out the TCAM that retrieves more at a high speed than trie tree.
Figure 19 is the structure example 1 of packet transfer device that the LSDB indexing unit 210 of structure example 1 has been installed.It is a kind of like this structure: on IF, be equipped with the LSDB indexing unit 210 different with routing table indexing unit 215.Therefore this example, has the advantage that route table search device 215 is not impacted (speed, installation etc.) owing to be equipped with the LSDB indexing unit 210 different with routing table indexing unit 215.
Figure 21 is the packet transfer device structure example 2 that the LSDB indexing unit 211 of structure example 2 has been installed.This example utilizes the routing table indexing unit 216 of the existing packet transfer device 230 of Figure 29 to implement the LSDB retrieval.
LSDB indexing unit 210,211 shown in Figure 19, Figure 20 is got the physical structure identical with Figure 28, routing table indexing unit shown in Figure 29 215,216, and (NP is a processor, can become information processor), on function, even if on execution retrieval this point, also need identical functions.Therefore, in LSDB retrieval, also use existing packet transfer device 230 routing table indexing unit 216 be structure example 2.This example has been owing to utilized the routing table indexing unit 216 of existing packet transfer device 230, therefore, has the advantage that can finish with less cost.
As described above described, the 2nd execution mode of the present invention is: in the network that packet transfer devices such as using ip router makes, bear by the processing of cutting down the RS in the packet transfer device, thereby can make macroreticular with a management domain.
The present invention is in the network that packet transfer devices such as using ip router makes, and bear by the processing of cutting down the RS in the packet transfer device, thereby an available management domain makes macroreticular.Thus, can be corresponding with extensiveization of IP network, and can improve network manager, the network user's convenience.
Claims (2)
1. a LSD indexing unit is installed in the packet transfer device, and is arranged on carrying out in the interface of handling from the bag of incoming line input, it is characterized in that having:
Collector unit uses the controlling packet of Routing Protocol to collect received information;
Memory cell is stored at least a portion item of this collection and the information that receives;
Judging unit compares the information of this canned data with at least a portion item of the information that is newly received by described collector unit, judges the new and old of this information;
Discarded unit, judged result based on described judging unit, when the information of at least a portion item of the described information that newly receives is during than the also new information of described canned data, transmit newly arrived controlling packet with described information that newly receives to route control device, when the information of at least a portion item of the described information that newly receives is the information identical or older with described canned data, discarded newly arrived controlling packet with described information that newly receives; And
Delivery unit, judged result based on described judging unit, when the information of at least a portion item of the described information that newly receives is during than the also new information of described canned data, the information of at least a portion item that is sent to the controlling packet of described route control device is sent to LSD indexing unit in other interfaces.
2. LSD indexing unit according to claim 1 is characterized in that also having:
Judged result based on described judging unit, when the information of at least a portion item of the described information that newly receives is during than the also new information of described canned data, the information of at least a portion item that will have the newly arrived controlling packet of the described information that newly receives is sent to the unit of the LSD indexing unit in other interfaces; And
Be used to store the unit of information of at least a portion item of the described controlling packet that sends from other devices.
Applications Claiming Priority (6)
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| JP2003296408 | 2003-08-20 | ||
| JP2003-296408 | 2003-08-20 | ||
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| JP2003298734 | 2003-08-22 | ||
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| JP2003-298734 | 2003-08-22 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2004800010671A Division CN100499569C (en) | 2003-08-20 | 2004-08-18 | Protocol speed increasing device |
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| CN101330512A CN101330512A (en) | 2008-12-24 |
| CN101330512B true CN101330512B (en) | 2011-01-26 |
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| CN101741737B (en) * | 2009-12-08 | 2013-01-16 | 中兴通讯股份有限公司 | Maintenance method and device of route table |
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| CN1701577A (en) | 2005-11-23 |
| CN101330512A (en) | 2008-12-24 |
| CN100499569C (en) | 2009-06-10 |
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