CN101296178B - Inter-domain flux engineering route computing method and route computing device - Google Patents

Abstract

The present invention relates to a network technology and discloses a calculation method for an inter-domain traffic engineering path and a PCE. When the PCE is adopted to calculate the inter-domain traffic engineering path, if a first PCE discovers that an AS, to which the first PCE belongs, does not deploy the PCE in the downstream AS of an AS array, the first PCE can select a boundary node from the downstream AS to serve as a target node of partial calculation to calculate the path from an initial node to the boundary node, thus leading the deployed PCE to be fully utilized and improving the utilization rate of system resources; furthermore, as a partial path calculated by adopting the PCE is not the worst path, a final path comprising a non-worst path is not the worst path.

Description

Inter-domain traffic engineering path calculation method and path calculation device

technical field

The invention relates to network technology, in particular to a method and a path calculation device for inter-domain flow engineering path.

Background technique

With the expansion of network deployment and the development of General Multiple Protocol Label Switching (GMPLS: General Multiple Protocol Label Switch) technology, inter-domain traffic engineering will span different operators and cover the entire GMPLS network. Traffic engineering focuses on the optimization of the overall performance of the network. Its main goal is to provide efficient and reliable network services conveniently, optimize the use of network resources, and optimize network traffic. This is divided into two levels: one is traffic-oriented, that is, it focuses on how to improve the service quality of the network; the other is resource-oriented, that is, it focuses on how to optimize the use of network resources, and the most important thing is the effective use of bandwidth resources.

Constraint-based Shortest Path First (CSPF: Constraint-based Shortest Path First) calculation is an important part of GMPLS and Multi-Protocol Label Switching (MPLS: Multiple Protocol Label Switch) traffic engineering, between multiple autonomous systems (AS: Autonomous Systems) Path computation is very complicated and requires the cooperation of computing entities of different ASs, such as Path Computation Element (PCE: Path ComputationElement), to complete it together. At present, there are two most basic inter-domain traffic engineering path calculation methods, one is PCE-based reverse fallback path calculation (BRPC: Backward Recursive PCE-based Computation) method using path calculation device, in which PCE can be based on constraint conditions The network node, application or module that calculates the network path based on the network topology; the other is the Per-domain calculation method that does not use PCE.

When the BRPC method is used to calculate the inter-domain traffic engineering path, the network node that sends the inter-domain traffic engineering path calculation request to the PCE first sends the inter-domain traffic engineering path calculation request to the PCE in its AS, and the PCE will determine a route to the destination. The AS sequence of the node, and then transmits the inter-domain traffic engineering path calculation request to the downstream PCE on the AS sequence. The AS sequence close to the head node is called upstream, and the one close to the destination node is called downstream. When the inter-domain traffic engineering path calculation request is transmitted to the PCE of the AS where the destination node is located, that is, the most downstream PCE, the PCE searches for the boundary node in its AS that is connected to the AS where the upstream PCE is located; then it can (TE, Traffic Engineering) information, respectively calculate the optimal path from each border node to the destination node, and return each calculated path to the upstream PCE. After the upstream PCE receives the partial path to the destination node returned by the downstream PCE, if it finds that it is not the PCE of the first AS in the entire AS sequence, it will search for the boundary node in its AS that is connected to the AS where the upstream PCE is located, and then Then calculate the optimal path from each boundary node to the destination node. In this reverse calculation, until the PCE of the first AS in the AS sequence receives the calculation result of the downstream PCE, it can calculate the optimal path from the head node to the destination node.

When using the Per-domain calculation, the head node loosely specifies the border nodes or ASs that pass through the path to the destination node, and each border node or AS calculates the specific path to the next border node according to the topology of its own domain, and Replace the original loose path with the calculated path, so that the path from the head node to the destination node can be obtained through level-by-level calculation.

Since the calculation of the path will span different networks, the deployment of PCE on different networks may be different. Some networks may have deployed PCE, while some networks may not have deployed PCE. Since the BRPC method is based on PCE, when the path When the calculation spans the network where the PCE is deployed and the network where the PCE has not been deployed, the BRPC method cannot be used to calculate the path. At this time, the PCE will return an error because it cannot continue to send the inter-domain traffic engineering path calculation request, and can only use Per- Domain way to calculate. In the process of realizing the present invention, the inventor found that when performing path calculation between a PCE-deployed network and a PCE-undeployed network, only the Per-domain method has at least the following disadvantages: the PCE in the PCE-deployed network does not If it is not used, the PCE is idle when calculating the path, and the utilization rate of system resources is not high; furthermore, the path calculated by using the Per-domain method may be the worst path.

Contents of the invention

The purpose of the embodiments of the present invention is to provide an inter-domain traffic engineering path calculation method and path calculation device. Using the technical solution provided by the embodiments of the present invention, the path calculation device deployed in the autonomous system can be used.

The purpose of the embodiments of the present invention is achieved through the following technical solutions:

An embodiment of the present invention provides a method for calculating an inter-domain traffic engineering path, including:

The first path calculation device PCE receives a first inter-domain traffic engineering path calculation request that triggers a first calculation method, and the first inter-domain traffic engineering path calculation request carries a destination node identifier;

The first PCE determines that the first autonomous system AS to which the PCE belongs is not the last AS in the AS sequence to reach the destination node, and cannot send the second inter-domain traffic engineering to the first AS in the next AS in the AS sequence Path calculation request;

The first PCE selects a first border node connected to the first AS from the first AS in the next AS of the AS sequence;

The first PCE uses the first calculation method to calculate the path from the network node in the first AS to the first border node, and returns path result information, where the path result information includes the calculation result and additional information, and the additional information includes the The path calculation is a partial path calculation and the identification of the first boundary node.

Correspondingly, an embodiment of the present invention provides a path calculation device, including:

A calculation request receiving unit, configured to receive a first inter-domain traffic engineering path calculation request that triggers a first calculation mode, where the first inter-domain traffic engineering path calculation request carries a destination node identifier;

An autonomous system judging unit, configured to judge whether the first autonomous system AS to which the path computing device belongs is the last AS in the AS sequence to reach the destination node;

a path judging unit, configured to judge whether the first AS can send the first AS to the next AS in the AS sequence in the AS sequence when the autonomous system judging unit judges that the first AS is not the last AS in the AS sequence. Two inter-domain traffic engineering path calculation requests;

A boundary node selection unit, configured to, when the path judging unit judges that it cannot continue to send the second inter-domain traffic engineering path calculation request to the first AS in the next AS in the AS sequence, from the first AS in the selecting a first boundary node connected to the first AS from the next AS of the AS sequence;

a path calculation unit, configured to calculate a path from a network node in the first AS to the first boundary node in a first calculation manner;

The information return unit is configured to return the calculation result of the path calculation unit and return additional information, the additional information includes that the path calculation is a partial path calculation and an identification of the first boundary node.

Embodiments of the present invention provide another inter-domain traffic engineering path calculation method, including:

The first border node receives signaling from the second border node that triggers the second calculation mode, where the signaling carries the identity of the destination node;

The first border node judges that the border node is not the destination node, and the AS to which the border node belongs deploys the PCE;

The first boundary node sends to the PCE an inter-domain traffic engineering path calculation request that triggers a first calculation method, triggering the PCE to use the first calculation method to calculate a path from the first boundary node to the destination node;

After the first border node receives the calculation result calculated by the first calculation method returned by the PCE, replace the loose path carried by the signaling with the path in the calculation result, and continue

Signaling sent to the destination node.

Correspondingly, an embodiment of the present invention provides a network node device, including:

A signaling receiving unit, configured to receive signaling that triggers the second calculation method, where the signaling carries a destination node identifier;

a destination node judging unit, configured to judge whether the network node device is the destination node after the signaling receiving unit receives the signaling;

A path calculation device judging unit, configured to judge whether the first AS to which the network node device belongs deploys a PCE when the destination node judging unit judges that the network node device is not the destination node;

A calculation request sending unit, configured to send an inter-domain traffic engineering path calculation request to the PCE when the path calculation device judging unit determines that the first AS deploys a PCE, and trigger the PCE to use the first calculation method to calculate the path a path from a network node device to said destination node;

The path calculation result receiving unit is configured to receive the calculation result calculated by the first calculation method returned by the PCE, replace the loose path carried by the signaling with the path in the calculation result, and continue to initiate the arrival at the Signaling of the destination node.

From the above technical solutions provided by the embodiments of the present invention, it can be seen that when PCEs are deployed in the AS, the PCEs can be used to calculate inter-domain traffic engineering paths, so that all deployed PCEs can be utilized and the utilization rate of system resources can be improved; further , since some of the inter-domain traffic engineering paths calculated by PCE are not the worst paths, even if other partial inter-domain traffic engineering paths obtained when using boundary node calculations are the worst paths, the final entire inter-domain traffic engineering paths are also Won't be the worst path.

Description of drawings

Fig. 1 is the flowchart of the first embodiment of the method of the present invention;

Fig. 2 is the flowchart of the second embodiment of the method of the present invention;

Fig. 3 is the flowchart of the third embodiment of the method of the present invention;

Fig. 4 is the schematic diagram of the fourth embodiment of the method of the present invention;

Fig. 5 is the flowchart of the fifth embodiment of the method of the present invention;

Fig. 6 is the flowchart of the sixth embodiment of the method of the present invention;

FIG. 7 is a schematic structural diagram of the first embodiment of the path calculation device of the present invention;

FIG. 8 is a schematic structural diagram of a second embodiment of the path calculation device of the present invention;

FIG. 9 is a schematic structural diagram of a first embodiment of a network node device according to the present invention;

FIG. 10 is a schematic structural diagram of a second embodiment of a network node device according to the present invention.

Detailed ways

In order to make the object, technical solution, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples.

Fig. 1 is the flowchart of the first embodiment of the inventive method, as shown in Fig. 1, the first embodiment of the inventive method mainly comprises:

Step 101. The first PCE receives a first inter-domain traffic engineering path calculation request that triggers a first calculation method, and the first inter-domain traffic engineering path calculation request carries a destination node identifier;

The inter-domain traffic engineering path calculation request can come from a network node belonging to the same AS as the first PCE, that is, the head node, or from an upstream PCE; the first calculation method can be BRPC mode, or multi-PCE cooperation It can also be any calculation method that uses PCE for calculation; when the BRPC method is used, each PCE calculates that in the AS to which this PCE belongs, the boundary node or head node connected to the upstream AS will go to the downstream AS and have the same relationship with this AS. Paths between connected border nodes or destination nodes;

The inter-domain traffic engineering path calculation request includes the following information: the relevant information of the head node, such as the head node address, so that the final path can finally return to the head node; the destination node identifier, such as the address information of the destination node, etc., so that the PCE knows Destination node for path calculation; information about the calculation method used by the trigger can let the PCE know which calculation method should be used for path calculation, and the calculation method used can be limited from two aspects, one is in the inter-domain traffic engineering path calculation request Identifies the calculation method used, and the other is to send inter-domain traffic engineering path calculation requests according to the requirements of the calculation method;

Step 102, the first PCE determines that the first AS to which the PCE belongs is not the last AS in the AS sequence to reach the destination node;

Wherein, if the inter-domain traffic engineering path calculation request comes from an upstream PCE, the AS sequence is carried in the inter-domain traffic engineering path calculation request and sent to the first PCE;

If the inter-domain traffic engineering path calculation request comes from a head node, the AS sequence is determined by the first PCE according to the destination node identifier;

Each AS in the AS sequence has unique identification information. The first PCE can judge whether the first AS is the last AS in the AS sequence according to the identification of the first AS it belongs to. If not, it needs to continue to follow the AS sequence. Send down the inter-domain traffic engineering path calculation request;

Step 103, if it cannot continue to send the second inter-domain traffic engineering path calculation request to the next AS in the AS sequence of the first AS;

When PCE is used for path calculation, inter-domain traffic engineering path calculation requests need to be sent between PCEs. When an AS does not deploy PCE, inter-domain traffic engineering path calculation requests sent through PCE cannot continue to be sent to the AS; Routing information is used to determine whether to continue sending inter-domain traffic engineering path calculation requests. Routing information can be topology information maintained by PCE and/or traffic engineering information. Both topology information and traffic engineering information maintained by PCE are synchronized with the network, so Whether a PCE is deployed in the next AS can be judged based on topology information and/or traffic engineering information. When no PCE is deployed in the next AS, the inter-domain traffic engineering path calculation request cannot be sent to the next AS; the topology information includes The border node information connected by PCE, such as which routers are connected, etc.; TE information includes some policy-related information, such as router bandwidth and available bandwidth, and other information related to traffic engineering path calculation;

Step 104, the first PCE selects a first border node connected to the first AS from the next AS;

It can also be judged by routing information, because both topology information and TE information contain information about border nodes, so border nodes can be selected through the topology information and/or TE information maintained by itself; when there are multiple border nodes that can For selection, one can be randomly selected from these boundary nodes, or can be selected according to certain rules, such as priority or numbering order;

Step 105, the first PCE uses the first calculation method to calculate the path from the network node in the first AS to the first border node;

Because the inter-domain traffic engineering calculation request cannot be sent any more, the destination node of the first calculation mode is changed to the first boundary node, so only the path between the network node in the first AS and the first boundary node is calculated; when the first PCE When the inter-domain traffic engineering path calculation request is received from the upstream PCE, the network node in the first AS is a border node connected to the AS to which the upstream PCE belongs; when the inter-domain traffic engineering path calculation request is from the head node, the network node is the head node.

Step 106: return route result information, the route result information includes the calculation result and additional information, the additional information includes the route calculation as a partial route calculation and the identification of the first boundary node;

When the inter-domain traffic engineering path calculation request comes from the head node, it returns to the head node; when the inter-domain traffic engineering path calculation request comes from the upstream PCE, it returns to the upstream PCE, and the calculation result returned to the upstream PCE is: first The path from the boundary node connected to the AS to which the upstream PCE belongs in the first AS calculated by the PCE to the first boundary node; compared with the calculation that originally needs to be calculated to the destination node, the first boundary node is used as the destination The calculation of a node is an incomplete calculation, so it is necessary to mark the calculation as a partial path calculation in the path calculation result, so that the upstream PCE can judge that the calculation is a partial path calculation according to this identification, and at the same time return the identification of the first boundary node to be able to Let the upstream PCE know that the path to the destination node has not been obtained, so the head node that triggers this calculation can finally know that the path to the destination node has not been obtained, so that the head node can trigger the first border node to perform path calculation, and then get to The path of the destination node; wherein the identifier of the first border node may be the network address of the first border node in the network, or the number of the first border node in the network, etc., which can uniquely determine the information of the first border node;

It can be seen from the above that, compared with the prior art that directly returns an error when the next AS does not deploy the PCE, this embodiment can use the deployed PCE even if the next AS does not deploy the PCE when the PCE is deployed in the AS. Part of the path calculation is performed, so that all deployed PCEs are utilized and the utilization rate of system resources is improved.

Fig. 2 is a flow chart of the second embodiment of the method of the present invention, and this embodiment is described by taking the BRPC method as a specific example. As shown in Figure 2, the second embodiment of the method provided by the present invention comprises the following steps:

Step 201, the first PCE receives a first inter-domain traffic engineering path calculation request that triggers the BRPC mode from the head node, and the first inter-domain traffic engineering path calculation request carries a destination node identifier;

The head node may be any network node in the first AS to which the first PCE belongs;

Step 202, the first PCE determines the AS sequence to the destination node according to the destination node identifier, and determines that the first AS to which the PCE belongs is not the last AS of the AS sequence;

Step 203, if it is not possible to continue sending the second inter-domain traffic engineering path calculation request to the first AS in the next AS in the AS sequence;

Step 204, the first PCE judges whether the first inter-domain traffic engineering route calculation request includes information allowing partial route calculation results; if yes, enter step 205; if no, end;

In practical applications, the policies of each AS may be different. Some network nodes allow partial path calculation results, while some network nodes do not allow partial path calculation results. Whether the network node allows partial path calculation results is used in inter-domain traffic engineering path calculation. There is an identifier in the request, so it is necessary to judge whether the inter-domain traffic engineering path calculation request includes information that allows partial path calculation results, so that only partial paths are returned to network nodes that allow partial path calculation results, so that the returned partial paths can be used identified by network nodes;

Step 205, the first PCE selects a first border node connected to the first AS from the next AS;

Step 206, the first PCE calculates the path from the head node to the first border node in BRPC mode;

Step 207, return the calculation result to the head node, and return additional information at the same time, the additional information includes that the path calculation is a partial path calculation and the identification of the first boundary node;

Among them, the calculation result returned to the head node is: the first PCE selects the optimal path from the calculated path from the head node to the first border node, and combines the optimal path with all the ASs starting from the next AS in the AS sequence. Of course, this is the case when the BRPC method is used for calculation, because the BRPC method calculates part of the optimal path, but when other methods are used, such as multi-PCE cooperation, the return may not be part of the optimal path. An optimal path may be just a non-worst path;

The first PCE will calculate multiple paths to the first boundary node using the BRPC method, but the head node only needs one path, so the optimal path is selected from the multiple paths calculated according to the BRPC method; and because the head node needs a The complete path to the destination node, so the optimal path and the loose path formed by all ASs starting from the next AS in the AS sequence are returned to the head node, so that the head node can get a complete path;

Step 208, the head node recognizes that the path calculation is a partial path calculation, and initiates signaling to establish the path; when the signaling is transmitted to the first border node, triggers the first border node to use the second calculation method to calculate the path to the destination node; end;

Here, the second calculation method may adopt a Per-domain method, or other calculation methods that do not need to use PCE for calculation, such as the shortest path first, random path selection, and the like.

In this embodiment, when the PCE is deployed in the AS where the head node is located, the PCE can be used for calculation in the BRPC mode, so that all the deployed PCEs are utilized and the utilization rate of system resources is improved; The path is a part of the optimal path, so even if the other part of the path calculated by the second calculation method is the worst path, the final entire path will not be the worst path.

The present invention further provides a third embodiment of the method, as shown in Figure 3, comprising the following steps:

Step 301. The first PCE receives a first inter-domain traffic engineering path calculation request that triggers the first calculation mode from the second PCE;

Step 302, the first PCE determines that the first AS to which the PCE belongs is not the last AS in the AS sequence carried in the first inter-domain traffic engineering path calculation request;

Step 303, if it cannot continue to send the second inter-domain traffic engineering path calculation request to the first AS in the next AS in the AS sequence;

Step 304, the first PCE judges whether the first inter-domain traffic engineering route calculation request includes information allowing partial route calculation results; if yes, enter step 305; if no, end;

Step 305, the first PCE selects a first border node connected to the first AS from the next AS;

Step 306, the first PCE uses the first calculation method to calculate the path from the boundary node connected to the upstream AS in the first AS to the first boundary node;

Step 307, return the calculation result to the second PCE, and return additional information at the same time, the additional information includes that the path calculation is a partial path calculation and the identification of the first boundary node;

The calculation result returned to the second PCE is: the path from the boundary node connected to the upstream AS in the first AS calculated by the first PCE to the first boundary node; , after each PCE calculates the path, it must return the calculated path to the upstream PCE, so that the upstream PCE can recalculate on the basis of the path returned by the downstream PCE;

Step 308: Based on the calculation result returned by the first PCE, the second PCE calculates the path from the border node connected to the upstream AS in the second AS to which the second PCE belongs to the first border node, and sends the new Computational results and additional information are returned to its upstream PCE;

Among them, the return of calculation results and additional information is returned to the upstream PCE according to the AS sequence;

Step 309, until the most upstream PCE receives the calculation result from its downstream PCE, calculates the path from the head node to the first border node on the basis of the calculation result;

In step 310, the most upstream PCE selects a non-worst path from the calculated paths, and combines the non-worst path with all AS sequences starting from the first AS in the next AS of the AS sequence. The loose path combined by AS is returned to the head node; where additional information can be combined in this loose path;

Step 311, the head node recognizes that the path calculation is a partial path calculation, and initiates signaling to establish a path; when the signaling is transmitted to the first border node, it triggers the first border node to use the second calculation method to calculate the path to the destination node; end ;

In this embodiment, when the PCE is deployed in the AS, the PCE can be used to calculate the inter-domain traffic engineering path, so that all the deployed PCEs are utilized and the utilization rate of system resources is improved; further, because the part calculated by the PCE None of the paths will be the worst path, so even if other partial paths calculated by the second calculation method are the worst paths, the final entire path will not be the worst path.

For example, in the embodiment of the present invention, the following method of identifying the route calculation as a partial route calculation in the calculation result can be adopted: directly add An identification bit, the RP OBJ with the identification bit added is shown in Table 1:

Table 1, RP OBJ format

As shown in Table 1, it describes the situation that a flag "I" is added to the existing RP OBJ to indicate that the path calculation is a partial path calculation. After the PCE receives the RP OBJ sent by the downstream PCE, if there is " I" flag, then know that the path calculation is a partial path calculation, so as to perform corresponding operations; where Reserved is a reserved field, used to reserve space for future expansion; Flags is a flag field, and the position occupied by Flags is reserved or not. There is no defined flag, which is convenient for future expansion, and "I", "F", "O", "B" and "R" are all defined flags, where "I" is used for the increase of the present invention The flag bit that identifies the path calculation as a partial path calculation, of course, can also be represented by other flags such as "W" in practical applications; correspondingly, the flag bit "I" needs to be added to the inter-domain traffic engineering path calculation request, so that It means that the head node that sends this inter-domain traffic engineering path calculation request allows partial path calculation results, so only when the "I" flag is set in the inter-domain traffic engineering path calculation request, can the head node return partial path calculation results. The flag bit is not set by default in the inter-domain traffic engineering path calculation request. At this time, before performing partial BRPC calculation, the PCE must first confirm that there is a flag bit that allows partial path calculation results in the inter-domain traffic engineering path calculation request; Request-ID -number is the request sequence number, which binds the address of the head node and the PCE together, and can uniquely identify an inter-domain traffic engineering path calculation request, and of course it can also uniquely identify the calculation result of an inter-domain traffic engineering path calculation request ;The Optional TLV (optional parameter) part is the currently defined location for extending information. The solution is to add one or more TLVs here if necessary. The order in which the TLVs are placed does not matter.

However, in the embodiment of the present invention, since a flag bit "I" is newly added, a new TLV needs to be added in the Optional TLV part to describe from which AS does not support PCE, and to describe from which AS The selected boundary node, so that the head node can clearly know from which boundary node to use the Per-domain method to calculate the path; in practical applications, it can occupy two bytes of AS Number, or it can occupy 4 bytes of AS Number AS Number, of course, does not rule out the use of AS Numbers with other byte lengths; no matter how many bytes of ASNumber are used in practical applications, after adding a TLV that needs to be added in the embodiment of the present invention, if the Optional TLV part If it is not 4-byte alignment, fill in zeros in the part less than 4 bytes, because the messages and signaling processed by PCE and network nodes are all 4-byte alignment, which facilitates subsequent processing.

A specific example is given below to describe the method provided by the embodiment of the present invention. The schematic diagram of the fourth embodiment of the method of the present invention is shown in Figure 4:

The network node 1 belonging to the autonomous system 401 needs to establish a path of the network node 9 , wherein the network node 9 belongs to the autonomous system 403 , where the head node is the network node 1 and the destination node is the network node 9 . As shown in Figure 4, the autonomous system 401 and the autonomous system 402 deploy the first path computing device and the second path computing device respectively, while the autonomous system 403 does not deploy PCE; the network node 1, the network node 2 and the network node 3 belong to the autonomous System 401 ; network node 4 , network node 5 and network node 6 belong to autonomous system 402 , and network node 7 , network node 8 and network node 9 belong to autonomous system 403 . Network node 1, as the head node, sends the first inter-domain traffic engineering path calculation request to the first path calculation device, and the first path calculation device determines that the calculated autonomous system sequence is: autonomous system 401, autonomous system 402, autonomous system 403; A path calculation device sends the second inter-domain traffic engineering path calculation request to the second path calculation device, wherein the autonomous system sequence is included in the second inter-domain traffic engineering path calculation request; the second path calculation device finds that the autonomous system 403 has no path Computing device; select the network node 7 belonging to the autonomous system 403 as the destination node for partial path calculation, and use the BRPC method to perform path calculation, wherein the network node 7 is a border node connected with the autonomous system 402 in the autonomous system 403; the first path The calculation device and the second path calculation device jointly calculate the path from network node 1 to network node 7 as network node 1 -> network node 2 -> network node 4 -> network node 6 -> network node 7 . Finally, the calculation result returned by the first path calculation device to the border node 1 is network node 1 -> network node 2 -> network node 4 -> network node 6 -> network node 7 -> autonomous system 403 . Network node 1 uses this path to initiate signaling. When the signaling reaches network node 7 along this path, network node 7 will process the autonomous system 403 in the path, and calculate the path from network node 7 to network node 9 in a per-domain manner. ;

It can be seen from the above that this embodiment makes use of all the deployed PCEs and improves the utilization rate of system resources; furthermore, since the partial paths calculated by the BRPC method are the optimal paths, even when using another calculation method The worst path is obtained when calculating other partial paths, and the final entire path will not be the worst path either.

The program may be stored in a computer-readable storage medium. When the program is executed, the program includes the following steps: the first path calculation device PCE receives a first inter-domain traffic engineering path calculation request that triggers the first calculation method, The first inter-domain traffic engineering path calculation request carries the destination node identifier; the first PCE determines that the first autonomous system AS to which the PCE belongs is not the last AS in the AS sequence to the destination node, and cannot continue to the first AS. The AS sends a second inter-domain traffic engineering path calculation request at the next AS in the AS sequence; the first PCE selects the first boundary connected to the first AS from the first AS in the next AS in the AS sequence node; the first PCE uses a first calculation method to calculate the path from the network node in the first AS to the first border node, and returns path result information, where the path result information includes calculation results and additional information, and the additional information It includes that the path calculation is a partial path calculation and an identifier of the first boundary node. The storage medium, such as: ROM/RAM, magnetic disk, optical disk, etc.

When using the method of calculating inter-domain traffic engineering paths using border nodes, such as using the Per-domain method to calculate inter-domain traffic engineering paths, the network node that initiates the signaling, that is, the head node, needs to specify a loose path to the destination node, and then loosen the path Each border node on the loose path needs to calculate the path between it and the next border node on the loose path; of course, the loose path may also specify an AS, and at this time each border node in the AS needs to calculate the path to the next border node The path of a border node in the AS until the signaling is delivered to the destination node; when the signaling reaches a border node, the border node finds that the AS to which it belongs has deployed a PCE, and it can calculate the inter-domain traffic engineering path calculation request Send it to the PCE, trigger the PCE to calculate the remaining path, so that the deployed PCE can be utilized; thus the present invention provides a fifth embodiment of the method, as shown in Figure 5, the method embodiment includes the following steps:

Step 501, the first border node receives a signaling from a certain network node that triggers the second calculation method, and the signaling carries a destination node identifier;

Step 502, the first border node judges that the border node is not the destination node, and the AS to which the border node belongs deploys the PCE;

The identification of the destination node can be compared with the identification of the first border node, so that it can be judged whether the border node is the destination node; it can be determined according to the routing information maintained by the border node whether the AS belonging to the border node deploys PCE;

Step 503, the first border node sends to the PCE an inter-domain traffic engineering path calculation request that triggers the first calculation method, triggering the PCE to use the first calculation method to calculate the path from the first border node to the destination node; The loose path is carried in the request as a constraint;

Since PCE is deployed in the AS where the first border node resides, the first border node can send an inter-domain traffic engineering path calculation request to the PCE, thereby triggering the PCE to calculate the path; the inter-domain traffic engineering path calculation request includes the destination node Identification, and relevant information triggering the first calculation method;

Step 504: After receiving the calculation result calculated by the first calculation method returned by the PCE, the first border node sends the signaling to the destination node by replacing the loose path in the signaling with the path in the calculation result;

After the PCE calculates the path from the first boundary node to the destination node according to the first calculation method, select one or all of the calculated paths and return them to the first boundary node, specifically how to return to the first calculation method adopted Definitely, for example, when the BRPC method is used, the return is an optimal path; after the first border node receives the path, it will replace the loose path in the signaling with the path in the calculation result, and send the signaling to the destination node.

This embodiment describes the situation of switching from the calculation method of boundary nodes to the calculation method of PCE calculation, so that the PCE deployed in the AS can be fully utilized and the utilization rate of system resources is improved; further, the calculation obtained when using PCE Part of the path will not be the worst path, so it is guaranteed that the entire path will not be the worst path.

Furthermore, in practical applications, some boundary nodes do not allow partial path calculation results, so the sixth embodiment of the method provided by the present invention is shown in Figure 6, including the following steps:

Step 601, the first border node receives a signaling from a certain network node that triggers the second calculation mode, and the signaling carries a destination node identifier;

Step 602, the first border node judges that the border node is not the destination node, and the AS to which the border node belongs deploys the PCE;

Step 603, the first border node judges whether the border node is allowed to switch to the first calculation method using PCE for calculation, if yes, go to step 604; if not, go to step 606;

Among them, whether to allow switching can be manually configured on the boundary node of the domain by default switching, or not switching by default, or deciding whether to switch according to the policy;

Step 604, the first border node sends to the PCE an inter-domain traffic engineering path calculation request that triggers the first calculation method, triggering the PCE to use the first calculation method to calculate the path from the first border node to the destination node;

Step 605: After the first border node receives the path calculation result calculated by the first calculation method returned from the PCE, it sends the signaling of the path in the calculation result to the destination node instead of the loose path in the signaling; end ;

Step 606, the first border node uses the second calculation method to continue to transmit signaling; end;

It can be seen from the above that in this embodiment, the first border node can also decide whether to allow partial calculation results according to the policy when sending the inter-domain traffic engineering path calculation request that triggers the first calculation method to the PCE, so that it can be switched flexibly when needed The calculation method enables the deployed PCE to be fully utilized, thereby improving the utilization rate of system resources; furthermore, since some paths obtained by using PCE calculation are not the worst path, the final path including the non-worst path will not be the worst path.

The above describes the two cases where the boundary node calculation method is switched to the PCE calculation method and the PCE calculation method is switched to the boundary node calculation method in practical applications. By using the method provided by the embodiment of the present invention, the deployed PCEs can be fully utilized, and the whole path can contain non-worst paths calculated by means of the path calculation device.

The program can be stored in a computer-readable storage medium. When the program is executed, it includes the following steps: the first border node receives a signaling from the second border node that triggers the second calculation method, and the signal Let carry the destination node identifier; the first border node judges that the border node is not the destination node, and the AS to which the border node belongs deploys a PCE; the first border node sends the inter-domain traffic engineering triggering the first calculation method to the PCE A path calculation request, triggering the PCE to use the first calculation method to calculate the path from the first boundary node to the destination node; the first boundary node receives the calculation calculated by the first calculation method returned by the PCE After the result, the path in the calculation result is replaced by the loose path carried in the signaling, and the signaling sent to the destination node is continued. The storage medium, such as: ROM/RAM, magnetic disk, optical disk, etc.

As shown in Figure 7, the first embodiment of the path calculation device provided by the present invention includes:

A calculation request receiving unit 701, configured to receive a first inter-domain traffic engineering path calculation request that triggers a first calculation mode, where the first inter-domain traffic engineering path calculation request carries a destination node identifier;

An autonomous system judging unit 702, configured to judge whether the first AS to which the path computation device belongs is the last AS in the AS sequence reaching the destination node;

The path judging unit 703, if the autonomous system judging unit judges that the first AS is not the last AS in the AS sequence, judge whether it can continue to send the second inter-domain traffic engineering to the first AS in the next AS in the AS sequence Path calculation request;

The boundary node selection unit 704, if the path judging unit judges that it cannot continue to send the second inter-domain traffic engineering path calculation request to the first AS in the next AS in the AS sequence, the next AS in the AS sequence from the first AS Select the first border node connected to the first AS;

a path calculation unit 705, configured to calculate a path from a network node in the first AS to the first border node in a first calculation manner;

When the inter-domain traffic engineering path calculation request comes from the upstream PCE, the network node in the above-mentioned first AS is the border node in the first AS that is connected to the AS to which the upstream PCE belongs; when the inter-domain traffic engineering path calculation request comes from the head node, The network node in the first AS is the head node. At this time, the head node and the PCE belong to the same AS;

The information return unit 706 is configured to return the calculation result of the path calculation unit and return additional information, the additional information includes the path calculation as a partial path calculation and the identification of the first boundary node;

In this embodiment using PCE, when only some ASs have deployed PCEs, the deployed PCEs can use PCEs to calculate inter-domain traffic engineering paths, so that all deployed PCEs can be utilized and the utilization rate of system resources is improved. ; Further, because the partial paths calculated by using the PCE calculation method are not the worst paths, the final path will not be the worst path.

The present invention further provides a second embodiment of the path computing device. Compared with the first embodiment of the path computing device, this embodiment further includes a partial path judging unit, as shown in FIG. 8:

A calculation request receiving unit 801, configured to receive a first inter-domain traffic engineering path calculation request that triggers a first calculation mode, where the first inter-domain traffic engineering path calculation request carries a destination node identifier;

An autonomous system judging unit 802, configured to judge whether the first AS to which the path computation device belongs is the last AS in the AS sequence reaching the destination node;

The path judging unit 803, if the autonomous system judging unit judges that the first AS is not the last AS in the AS sequence, judge whether it can continue to send the second inter-domain traffic engineering to the first AS in the next AS in the AS sequence Path calculation request;

A partial path judging unit 804, configured to judge whether the inter-domain traffic engineering path computation request includes information allowing partial path computation results when the path judging unit judges that the inter-domain traffic engineering path computation request cannot be sent to the next AS in the AS sequence;

The boundary node selecting unit 805, if the partial path judging unit judges that the inter-domain traffic engineering path calculation request includes information allowing partial path calculation results, selects the first AS from the next AS in the AS sequence that is connected to the first AS first boundary node;

a path calculation unit 806, configured to calculate a path from a network node in the first AS to the first border node by using a first calculation method;

The information return unit 807 is configured to return the calculation result of the path calculation unit and return additional information, the additional information includes that the path calculation is a partial path calculation and the identification of the first boundary node;

The partial path judging unit added in this embodiment judges whether the inter-domain traffic engineering path calculation request includes information that allows partial path calculation results. In practical applications, the policies of each AS may be different, and some network nodes allow partial path calculation. As a result, some network nodes do not allow partial path calculation results, so it is necessary to judge whether the inter-domain traffic engineering path calculation request includes information that allows partial path calculation results

As shown in Figure 9, the first embodiment of the network node device provided by the present invention includes:

A signaling receiving unit 901, configured to receive signaling that triggers the second calculation method, where the signaling carries a destination node identifier;

A destination node judging unit 902, configured to judge whether the network node device is a destination node after the signaling receiving unit receives the signaling;

The path calculation device judgment unit 903 is configured to judge whether the first AS to which the network node device belongs deploys a PCE when the destination node judgment unit judges that the network node device is not the destination node;

A calculation request sending unit 904, configured to send an inter-domain traffic engineering path calculation request to the PCE when the path calculation device judging unit determines that a PCE is deployed in the first AS, and trigger the PCE to use the first calculation method to calculate the local network node The inter-domain traffic engineering path from the device to the destination node;

The path calculation result receiving unit 905 is configured to receive the calculation result calculated by the first calculation method returned by the PCE, replace the loose path carried in the signaling with the path in the calculation result, and continue to initiate signaling to the destination node.

The network node device provided in the embodiment of the present invention can be used as a border node in the network. In this embodiment, when a PCE is deployed in the AS to which the border node belongs, the PCE is directly triggered to calculate the remaining inter-domain traffic engineering path, so that the deployed PCE can be utilized and the utilization rate of system resources can be improved; further, because the PCE is calculated to obtain The path of will not be the worst path, so the final path will not be the worst path.

Furthermore, the present invention also provides a second embodiment of the network node device. Compared with the first embodiment of the network node device, this embodiment further includes a calculation mode switching judging unit, as shown in FIG. 10:

A signaling receiving unit 1001, configured to receive signaling that triggers the second calculation mode, where the signaling carries a destination node identifier;

A destination node judging unit 1002, configured to judge whether the network node device is a destination node after the signaling receiving unit receives the signaling;

The path calculation device judgment unit 1003 is configured to judge whether the first AS to which the network node device belongs deploys a PCE when the destination node judgment unit judges that the network node device is not the destination node;

The calculation mode switching judging unit 1004 is configured to judge whether the current boundary node is allowed to switch to the first calculation mode using PCE for calculation when the path calculation device judging unit judges that the first AS to which the network node device belongs deploys a PCE;

The calculation request sending unit 1005 is configured to send an inter-domain traffic engineering path calculation request to the PCE when the calculation mode switching judging unit judges that the boundary node is allowed to switch to the first calculation mode using the PCE for calculation, and trigger the PCE Using the first calculation method to calculate the inter-domain traffic engineering path from the network node device to the destination node;

The path calculation result receiving unit 1006 is configured to receive the calculation result calculated by the first calculation method returned by the PCE, replace the loose path carried in the signaling with the path in the calculation result, and continue to initiate signaling to the destination node.

When the network node device in this embodiment is used as a border node, it can be ensured that the PCE is triggered to perform inter-domain traffic engineering path calculation only when the border node is allowed to switch to the first calculation mode using PCE for calculation.

It can be seen from the above that by using the embodiment provided by the present invention, when PCE is deployed in the AS, even if the first downstream AS of the AS does not deploy PCE, it can also use the already deployed PCE to perform part of the path calculation, so that the deployed All PCEs are utilized to improve the utilization rate of system resources; furthermore, since some paths calculated by using PCE are not the worst paths, the final path including non-worst paths will not be the worst path. In some embodiments of the present invention, further, only when the head node or the border node allows partial path calculation results, the hybrid calculation of the border node calculation method and the path calculation device calculation method will be used, and the head node or border node It allows flexible switching of calculation methods when calculating results for some paths, so that deployed PCEs can be fully utilized, thereby improving the utilization of system resources.

The above is a detailed introduction of the inter-domain traffic engineering path calculation method and PCE provided by the embodiment of the present invention. The description of the above embodiment is only used to help understand the method and the idea of the present invention; at the same time, the general technology in the field Personnel, according to the idea of the present invention, there will be changes in the specific implementation and the scope of application. In summary, the content of this specification should not be construed as limiting the present invention.

Claims (13)

1. an inter-domain flux engineering route computing method is characterized in that, comprising:

The first path calculation device PCE receives the first inter-domain flux engineering route computation requests that triggers first account form, and the described first inter-domain flux engineering route computation requests is carried the destination node sign;

The first autonomous system AS that the one PCE judges this PCE ownership arrives last AS in the AS sequence of described destination node, and can not send the second inter-domain flux engineering route computation requests at next AS of described AS sequence to an AS;

The one PCE chooses with a described AS at next AS of described AS sequence from an AS first boundary node that is connected;

The one PCE adopts first account form to calculate the path to described first boundary node of network node among the described AS, the return path object information, described route result information comprises result of calculation and additional information, and described additional information comprises that described path computing is the sign of part path computing and described first boundary node.

2. inter-domain flux engineering route computing method as claimed in claim 1 is characterized in that, a PCE chooses with a described AS from described next AS first boundary node that is connected, and comprising:

A described PCE judges whether the described first inter-domain flux engineering route computation requests comprises the information that allows part path computing result, if a PCE chooses with a described AS at next AS of described AS sequence from an AS first boundary node that is connected.

3. inter-domain flux engineering route computing method as claimed in claim 1 or 2, it is characterized in that, the described first inter-domain flux engineering route computation requests is during from head node, described route result information returns to described head node, and described head node is the network node that belongs to same AS with a described PCE; Described path computing result is loose path, non-worst path that the described head node that this loose path is calculated from this PCE by a described PCE is selected to the path of described first boundary node and is merged into from a described AS all AS that next AS begins described AS sequence in the described AS sequence.

4. inter-domain flux engineering computational methods as claimed in claim 3 is characterized in that, described head node further comprises after receiving described loose path and described additional information:

Determine that according to described additional information described path computing is imperfect calculating, transmit signaling to described first boundary node according to the non-worst path in the described loose path, trigger described first boundary node and adopt second account form to calculate the path of described first boundary node to described destination node.

5. inter-domain flux engineering route computing method as claimed in claim 3 is characterized in that, described AS sequence is being received between described territory after the flow rate calculation request by a described PCE, determines according to described destination node sign.

6. inter-domain flux engineering route computing method as claimed in claim 1 or 2 is characterized in that, the described first inter-domain flux engineering route computation requests sends by belonging to the PCE of an AS in the upstream AS of described AS sequence; Described route result information returns to the described PCE that belongs to an AS in the upstream AS of described AS sequence, and described path computing result is: have the boundary node that is connected to arrive the path of described first boundary node with a described AS in the upstream AS of described AS sequence among the described AS that a described PCE calculates;

After the 2nd PCE that belongs to first AS of described AS sequence receives the route result information of returning from its downstream PCE, calculate the path of head node to described first boundary node, to the path of described first boundary node, select non-worst path from the head node that described the 2nd PCE calculates, all AS that described non-worst path and a described AS are begun from described next AS in described AS sequence merge into loose path and return to described head node, simultaneously described additional information is returned to described head node, described head node is the network node that belongs to same AS with a described PCE;

Head node determines that according to described additional information described path computing is imperfect calculating, transmit signaling to described first boundary node according to the described non-worst path in the described loose path, trigger described first boundary node and adopt second account form to calculate the path of described first boundary node to destination node.

7. inter-domain flux engineering route computing method as claimed in claim 6, it is characterized in that, described AS sequence is determined according to described destination node sign by described the 2nd PCE, is carried in the described first inter-domain flux engineering route computation requests and send to a described PCE.

8. a path calculation device is characterized in that, comprising:

The computation requests receiving element is used to receive the first inter-domain flux engineering route computation requests that triggers first account form, and the described first inter-domain flux engineering route computation requests is carried the destination node sign;

The autonomous system judging unit is used to judge whether the first autonomous system AS of this path calculation device ownership is last AS that arrives the AS sequence of described destination node;

When path judging unit, last AS that to be used at the described AS of described autonomous system judgment unit judges be not described AS sequence, judge whether and to send the second inter-domain flux engineering route computation requests to a described AS at next AS of described AS sequence;

Boundary node is chosen the unit, be used for can not continuing to a described AS when next AS of described AS sequence sends the second inter-domain flux engineering route computation requests in described path judgment unit judges, choosing among next AS of described AS sequence with a described AS from a described AS has first boundary node that is connected;

Path-calculating element is used for adopting first account form to calculate the path of a described AS network node to described first boundary node;

Information is returned the unit, is used for the result of calculation of described path-calculating element is returned, and returns additional information simultaneously, and described additional information comprises that described path computing is the sign of part path computing and described first boundary node.

9. path calculation device as claimed in claim 8 is characterized in that, further comprises:

Part path judging unit, be used for to continue to a described AS when next AS of described AS sequence sends the second inter-domain flux engineering route computation requests in described path judgment unit judges, judge whether the described first inter-domain flux engineering route computation requests comprises the information that allows part path computing result, if trigger described boundary node and choose described first boundary node of unit selection.

10. an inter-domain flux engineering route computing method is characterized in that, comprising:

First boundary node receives the signaling from triggering second account form of second boundary node, and described signaling is carried the destination node sign;

First boundary node judges that this boundary node is not described destination node, and the AS of this boundary node ownership has disposed PCE;

First boundary node sends the inter-domain flux engineering route computation requests that triggers first account form to described PCE, triggers described PCE and adopts first account form to calculate the path of described first boundary node to described destination node;

First boundary node with the loose path that the path in the described result of calculation replaces described signaling to carry, continues to send to the signaling of destination node after receiving the result of calculation that described first account form of employing that described PCE returns calculates.

11. inter-domain flux engineering route computing method as claimed in claim 10 is characterized in that, first boundary node sends the inter-domain flux engineering route computation requests that triggers first account form to described PCE, comprising:

First boundary node judges whether this boundary node allows to switch to described first account form, if first boundary node sends the inter-domain flux engineering route computation requests that triggers described first account form to described PCE.

12. a network node device is characterized in that, comprising:

The signaling receiving element is used to receive the signaling that triggers second account form, and described signaling is carried the destination node sign;

The destination node judging unit is used for after described signaling receiving element receives described signaling, judges whether the present networks node apparatus is described destination node;

The path calculation device judging unit is used for when described destination node judgment unit judges goes out the present networks node apparatus and is not described destination node, judges whether an AS of present networks node apparatus ownership has disposed PCE;

The computation requests transmitting element, be used for when the described AS of described path calculation device judgment unit judges has disposed PCE, send the inter-domain flux engineering route computation requests to described PCE, trigger described PCE and adopt first account form to calculate the path of present networks node apparatus to described destination node;

Path computing is receiving element as a result, be used to receive the result of calculation that described first account form of employing that described PCE returns calculates, with the loose path that the path in the described result of calculation replaces described signaling to carry, continue to initiate to arrive the signaling of described destination node.

13. network node device as claimed in claim 12 is characterized in that, further comprises:

Account form switching judging unit, be used for when an AS of described path calculation device judgment unit judges present networks node apparatus ownership has disposed PCE, judge whether the present networks node apparatus allows to switch to described first account form, if allow, trigger described computation requests transmitting element and send the inter-domain flux engineering route computation requests to described PCE.

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