WO2018113793A1

WO2018113793A1 - Path computation method and apparatus, pcc, pce and path computation system

Info

Publication number: WO2018113793A1
Application number: PCT/CN2017/118270
Authority: WO
Inventors: 杨美琴
Original assignee: 中兴通讯股份有限公司
Priority date: 2016-12-23
Filing date: 2017-12-25
Publication date: 2018-06-28
Also published as: CN108243105B; CN108243105A

Abstract

Proposed are a path computation method and apparatus, a PCC, a PCE and a path computation system. The path computation method comprises the steps, executed at a PCC side, of: establishing a plurality of path computation requests, the plurality of path computation requests respectively comprising a corresponding path option; associating the plurality of path computation requests to be a group of synchronous path computation requests, so that a PCE can perform path computation on path options in the plurality of path computation requests according to a path computation result unique principle; and sending the plurality of path computation requests to the PCE.

Description

Path calculation method and device, PCC, PCE and path calculation system

Technical field

The present invention relates to the field of communications technologies, and in particular, to a path calculation method and apparatus, a Path Computation Client (PCC), a Path Computation Element (PCE), and a path calculation system.

Background technique

In the Internet Protocol (IP)/Multi-Protocol Label Switching (MPLS) network for data communication, two Label Switching Routers (LSRs) can be displayed according to the user-specified display path. Or a dynamic path, generating a transmission path that meets the bandwidth and other restrictions, and retaining bandwidth resources and allocating labels through the Resource Reservation Protocol (RSVP) on the transmission path, thereby establishing end-to-end traffic engineering (Traffic Engineering) , TE) tunnel (MPLS-TE tunnel).

A Path Computation Element (PCE) refers to an entity that calculates a network path or route based on a network topology using constraints. The PCE can be located on a network node or a device such as a server outside the network. The PCE can calculate the Label Switched Path (TE LSP) by accessing the traffic engineering database and by bandwidth and other constraints. In the prior art, it is proposed that a Path Computation Client (PCC) submits a path calculation request to a Path Computation Element (PCE), and the PCE returns a path calculation result.

When establishing an MPLS-TE tunnel, there may be multiple path options, each of which contains its own path restrictions, such as nodes that must pass, nodes that need to be excluded, and so on. In the known technique, when the PCC sends a path calculation request to the PCE, only one path option is included in the sent path calculation request (for example, according to the RFC 5440 PCE communication protocol), and the LSP path calculation problem of multiple path options cannot be solved. .

Summary of the invention

The invention provides a path calculation method and device, a PCC, a PCE and a path calculation system.

According to an aspect of the present invention, a path calculation method is provided. The path calculation method includes the step of performing on a path calculation client (PCC) side: establishing a plurality of path calculation requests, the plurality of path calculation requests respectively including corresponding path options; associating the plurality of path calculation requests with a set of synchronization path calculation requests to enable a path calculation unit (PCE) to perform path calculation on the path option in the plurality of path calculation requests according to a path calculation result unique principle; and send the plurality of path calculation requests to the Said PCE.

According to another aspect of the present invention, a path calculation method is provided. The path calculation method includes the step of performing, on the PCE side, receiving a plurality of path calculation requests sent by the PCC, the plurality of path calculation requests being associated as a set of synchronization path calculation requests; and calculating a request for the plurality of paths The path option in the path calculation is performed according to the unique principle of the path calculation result, and the path calculation result is obtained.

According to another aspect of the present invention, a path calculation device is provided. The path calculation device is disposed on the PCC side, and includes: a request establishment module configured to establish a plurality of path calculation requests, the multiple path calculation requests respectively including corresponding path options; an association module configured to The plurality of path calculation requests are associated as a set of synchronization path calculation requests, so that the PCE can perform path calculation on the path option in the plurality of path calculation requests according to the path calculation result unique principle; and the PCC transmission module is configured to A plurality of path calculation requests are sent to the PCE.

According to another aspect of the present invention, a path calculation device is provided. The path calculation device is disposed on the PCE side, and includes: a PCE receiving module configured to receive a plurality of path calculation requests sent by the PCC, the multiple path calculation requests being associated as a set of synchronization path calculation requests; and a path And a calculation module configured to perform path calculation on the path option in the plurality of path calculation requests according to a path calculation result unique principle, to obtain a path calculation result.

In an embodiment, the path option in the multiple path calculation requests is performed according to the path calculation result unique principle, and the step of obtaining the path calculation result includes: sequentially performing the path option in the multiple path calculation requests. a path calculation; and if the path calculation performed on the path option in the current path calculation request is successful, the path option that the path is successfully calculated is used as the path calculation result, and the path calculation request subsequent to the current path calculation request is The path option does not perform path calculations.

According to another aspect of the present invention, a PCC is provided. The PCC includes the aforementioned path calculation device disposed on the PCC side.

According to another aspect of the present invention, a PCE is provided. The PCE includes the aforementioned path calculation device disposed on the PCE side.

According to another aspect of the present invention, a path calculation system is provided. The path computation system includes the aforementioned PCC.

According to another aspect of the present invention, a path calculation system is provided. The path computation system includes the aforementioned PCE.

According to another aspect of the present invention, a path calculation system is provided. The path calculation system includes the aforementioned PCC and the aforementioned PCE.

DRAWINGS

1 is a flowchart of a path calculation method according to a first embodiment of the present invention;

2 is a flowchart of a path calculation method according to a second embodiment of the present invention;

3 is a flowchart of a path calculation method according to a third embodiment of the present invention;

4 is a schematic diagram of establishing a tunnel by using a path calculation method according to a third embodiment of the present invention;

Figure 5 is a block diagram of a path calculation apparatus according to a fourth embodiment of the present invention;

Figure 6 is a block diagram of a path calculation apparatus according to a fifth embodiment of the present invention;

FIG. 7 is a schematic diagram showing an extension of a path calculation method using a SVEC object according to a third embodiment of the present invention.

detailed description

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

First embodiment

As shown in FIG. 1, this embodiment provides a path calculation method. The method includes the following steps performed on the PCC side:

Step S10: Establish a plurality of path calculation requests, each path calculation request including a path option corresponding to the path calculation request. Each path option has its own path limit. The path limitation is, for example, a node through which the path must pass, a node to be excluded from the path, and the like. Since a path calculation request needs to be established for each path option, in this step, a plurality of path calculation requests are established, each of which includes a corresponding one of the path options. The path options in the plurality of path calculation requests are different from each other.

Step S20: Associate the multiple path calculation requests into a set of synchronization path calculation requests, so that the PCE performs path calculation on the path option in the multiple path calculation requests according to the path calculation result unique principle. Associating a plurality of path calculation requests into a set of path calculation requests may be implemented using a synchronization vector (SVEC) object, that is, specifying, by the SVEC, the plurality of path calculation requests for a set of synchronization path calculation requests, the plurality of path calculation requests Interdependent. Therefore, on the PCE side, the path option in the multiple path calculation request can be calculated according to the path calculation result unique principle.

Step S30: Send a plurality of path calculation requests to the PCE. When the PCC sends the plurality of path computation requests to the PCE, the plurality of path computation requests carry the SVEC object such that the plurality of path computation requests are transmitted in a manner associated with a set of synchronization path computation requests by the SVEC object.

In the present invention, the path option in the multiple path calculation requests associated with a set of synchronization path calculation requests is calculated according to the path calculation result unique principle: the path options in the multiple path calculation requests are sequentially performed. Perform path calculation; as long as the path calculation result is obtained after performing path calculation for the path option in one of the path calculation requests (ie, the path calculation is successful), the path calculation result is used as the unique calculation request of the set of synchronization path The path calculates the result and does not process the path option (path option that has not been calculated) in the other path calculation request (path calculation). For example, for the M path calculation requests 1 to M indicated by the SVEC object, the PCE first performs path calculation on the path option 1 in the path calculation request 1; if the path calculation fails, performs path calculation on the path option 2; If the path calculation for the path option 2 is successful, the path calculation request 2 corresponding to the path option is sent to the PCC, and the path calculation request 3 to M following the path calculation request 2 indicated by the SVEC object is no longer performed. .

According to the technical solution provided by the embodiment of the present invention, the path option in the multiple path calculation requests that are associated with a set of synchronization path calculation requests is calculated according to the unique principle of the path calculation result, and the LSP can be effectively performed on multiple path options. Path calculation, and saves the interaction process between the PCC and the PCE when performing LSP path calculation on multiple path options, improving the path computation efficiency of the PCE (or the path computing device disposed on the PCE side).

Second embodiment

As shown in FIG. 2, on the basis of the first embodiment, after the step S30: sending a plurality of path calculation requests to the PCE, the steps performed on the PCC side further include:

Step S40: Receive a response message sent by the PCE corresponding to a set of synchronization path calculation requests, where the response message may include a path calculation result obtained by the path calculation. That is, the PCE sends a response message to the PCC for a set of synchronization path calculation requests sent from the PCC, the response message including the path calculation performed by the PCE for the set of synchronization path calculation requests by the unique principle of the path calculation result. Path calculation results.

Step S50: Determine the final path option based on the path calculation result.

The path calculation result may include a path calculation request in which the path calculation is successful. Therefore, the step S50 may specifically include: determining a path calculation request that the path calculation is successful according to the path calculation result; and selecting a path option in the path calculation request that the path calculation succeeds as a final path option (a path option for establishing a TE tunnel) .

Third embodiment

As shown in FIG. 3, this embodiment provides a path calculation method. The method includes the following steps performed on the PCE side:

Step S60: Receive a plurality of path calculation requests sent by the PCC, where the multiple path calculation requests are associated as a set of synchronization path calculation requests.

Step S70: Perform path calculation on the path option in the multiple path calculation request according to the path principle, and obtain the path calculation result.

The step S70 may specifically include: performing path calculation on the path options in the multiple path calculation requests in sequence; if the path calculation performed on the path option in the current path calculation request is successful, the path option that the path is successfully calculated is taken as The (unique) path calculation result, and the path option in the path calculation request (ie, the path calculation request that has not been processed) of the current path calculation request (ie, the path option that has not been calculated) is not performed.

As shown in Figure 4, for example, to establish a TE tunnel from R1 to R5, provide three path options: path-option 1: strictly pass R2- strictly through R4; path-option 2, strictly pass R3- strictly through R4 ;path-option 3, loose through R4. The SVEC associates the path computation request in which the three path options are located into a set of synchronization path calculation requests. The priority of the path calculation for the set of synchronization path calculation requests is path-option 1>path-option 2>path option 3. R1 acts as a PCC to initiate a path computation request to the PCE. Usually a path calculation request can only carry one path option, so the PCC sends the multiple path calculation request to the PCE. For example, if the path calculation performed by the PCE on the path-option 1 is unsuccessful; the PCC then performs path calculation on the path-option 2; in the case where the path calculation for the path-option 2 is unsuccessful, the PCC pair Then path calculation is performed on the path-option 3 path. If the path to path-option 3 is successfully calculated, the PCE will include path-option 3, that is, the path calculation request loosely passed through R4 is sent back to the PCC.

Although different priorities of a plurality of path options are defined in the present embodiment, priority may not be set for a plurality of path options. In the example of this embodiment, the PCE may perform path calculation on path options in other orders (such as path complexity order, node alphabetic order, random order, etc.).

As shown in FIG. 7, the P flag is used in the SVEC object to indicate that a plurality of path calculation requests are associated as a set of synchronization path calculation requests, and the path calculation request Request-ID-number#1 to Request-ID-number# is in the SVEC object. M These M path calculation requests are associated together, for example, M is 3. The path calculation request of Request-ID-number#1 carries the path restriction of path-option 1 (path option), and the path calculation request of Request-ID-number#2 carries the path restriction of path-option 2, Request-ID-number# The path calculation request of 3 carries the path limit of path-option 3. When the PCE has received the path calculation request corresponding to Request-ID-number#1 to Request-ID-number#3, the path-option 1 included in Request-ID-number#1 is processed first, if the path calculation is unsuccessful, Then, path-option 2 included in Request-ID-number#2 is calculated. If the path calculation is successful, path-option 3 in the path calculation request Request-ID-number#3 after Request-ID-number#2 is not performed. Path calculation. Then, the PCE responds to the PCC with a path response success response message, which carries Request-ID-number#2 and path-option 2. If the PCE fails to calculate the path of path-option 2 included in Request-ID-number#2, the PCE then processes the path calculation request after Request-ID-number#2, and so on.

If the PCC receives a response message sent back by the PCE, the PCC parses the response message to obtain a path calculation result. If the path calculation of the PCE is successful, the path selection success path option is determined according to the Request-ID-number# number carried in the response message, and the tunnel is established according to the path option. If the path calculation fails, the tunnel establishment fails.

In an example of the embodiment, after obtaining the path calculation result, the path calculation method further includes: on the PCE side, the corresponding group of synchronization path calculation request sends a response message including the path calculation result to the PCC.

In an example of the embodiment, after the path calculation is performed on the path options in the multiple path calculation requests in sequence, the path calculation method further includes: if the path calculation performed on the path options in the multiple path calculation requests fails, Then, on the PCE side, a path calculation response that fails to calculate the response path to the PCC is calculated corresponding to a set of synchronization paths.

Fourth embodiment

As shown in FIG. 5, this embodiment provides a path calculation device. The path calculation device is disposed on the PCC side, and includes: a request establishment module 10 configured to establish a plurality of path calculation requests, the path calculation requests respectively including corresponding path options; and an association module 20 configured to calculate a plurality of path calculation requests Correlation is a set of synchronization path calculation requests, so that the PCE can perform path calculation according to the path calculation result unique principle for the path option in the multiple path calculation requests; and the PCC sending module 30 is configured to send multiple path calculation requests to PCE.

As shown in FIG. 5, the path calculation apparatus of this embodiment may further include: a PCC receiving module 40 configured to send a PCE corresponding set of synchronization path calculation request after the sending module 30 sends a plurality of path calculation requests to the PCE. The response message, the response message includes the path calculation result obtained by the PCE through the path calculation; the path determination module 50 is configured to determine the final path option based on the path calculation result.

As shown in FIG. 5, according to an example of the embodiment, the path determining module 50 is specifically configured to: determine a path calculation request that the path calculation is successful according to the path calculation result; and use the corresponding path option in the path calculation request that is successfully calculated by the path as The final path option.

Fifth embodiment

As shown in FIG. 6, the embodiment provides a path calculation device. The path calculation device is disposed on the PCE side, and includes: a PCE receiving module 60 configured to receive a plurality of path calculation requests sent by the PCC, the plurality of path calculation requests being associated as a set of synchronization path calculation requests; the path calculation module 70 It is configured to perform path calculation according to the path principle of the path calculation result for the path option in the multiple path calculation request, and obtain the path calculation result.

In an example of the embodiment, the path calculation module 70 is specifically configured to: perform path calculation on the path options in the multiple path calculation requests in sequence; and if the path calculation performed on the path option in the current path calculation request is successful, The path option that successfully calculates the path is used as the path calculation result, and the path option in the path calculation request subsequent to the current path calculation request is not performed.

In an example of the embodiment, the path calculation module 70 is further configured to: if the path calculation performed on the path option in the multiple path calculation requests fails, the calculation of the request response path corresponding to the set of synchronization paths fails. Path calculation response.

As shown in FIG. 6, in an example of this embodiment, the path calculation apparatus of this embodiment may further include a PCE sending module 80. The PCE transmitting module 80 is configured to transmit a response message including a path calculation result corresponding to a set of synchronization path calculation requests.

Sixth embodiment

The present embodiment provides a PCC including a path calculation device disposed on the PCC side according to the above.

In an example of this embodiment, the path computing device disposed on the PCC side is the PCC.

Seventh embodiment

The present embodiment provides a PCE including a path calculation device disposed on the PCE side according to the above.

In an example of this embodiment, the path computing device disposed on the PCE side is the PCE.

Eighth embodiment

This embodiment provides a path calculation system including a PCC according to the above.

Ninth embodiment

This embodiment provides a path calculation system including a PCE according to the above.

Tenth embodiment

The embodiment provides a computer readable storage medium storing computer executable instructions that, when executed, implement the path calculation method of at least one of the above-described first to third embodiments.

According to the above embodiment, since the path selection in the plurality of path calculation requests associated with the set of synchronization path calculation requests by the PCE is performed according to the path calculation result unique principle, the path calculation can be effectively performed on the plurality of path options. Moreover, the interaction process between the PCC and the PCE is saved when path calculation is performed on multiple path options, and the path computation efficiency of the PCE is improved.

It will be understood by those skilled in the art that the embodiments of the present invention and the examples and/or features in the embodiments may be combined with each other without conflict. For example, the method in the first embodiment can be combined with the method in the second embodiment, and the PCC in the sixth embodiment and the PCE in the seventh embodiment can be combined in one network system, and the computer in the eighth embodiment The system and the computer system in the ninth embodiment may be the same computer system.

The technical means and functions of the present invention for achieving the intended purpose can be more deeply and specifically understood by the description of the specific embodiments. However, the accompanying drawings are only for the purpose of illustration and description, and are not intended to limit.

Industrial applicability

The path calculation method and device, the PCC, the PCE, and the path calculation system according to the present invention save the interaction process between the PCC and the PCE when performing path calculation on multiple path options, improve the path calculation efficiency of the PCE, and have industrial practicality. Sex.

Claims

A path calculation method, wherein the method includes the steps performed on a path computation client (PCC) side:

Establishing a plurality of path calculation requests, where the plurality of path calculation requests respectively include corresponding path options;

Associating the plurality of path calculation requests into a set of synchronization path calculation requests, so that the path calculation unit (PCE) can perform path calculation on the path option in the plurality of path calculation requests according to the path calculation result unique principle;

The plurality of path computation requests are sent to the PCE.
The path calculation method according to claim 1, wherein after transmitting the plurality of path calculation requests to the PCE, the method further comprises the step of performing on the PCC side:

Receiving, by the PCE, a response message sent by the group of synchronization path calculation requests, where the response message includes a path calculation result calculated by the PCE through the path;

A final path option is determined based on the path calculation result.
The path calculation method according to claim 2, wherein the determining the final path option based on the path calculation result comprises:

Determining, according to the path calculation result, a path calculation request that the path calculation succeeds;

The path option in the path calculation request for which the path calculation is successful is taken as the final path option.
A path calculation method, wherein the method includes the steps performed on the PCE side:

Receiving a plurality of path calculation requests sent by the PCC, the multiple path calculation requests being associated as a set of synchronization path calculation requests;

The path option in the plurality of path calculation requests is calculated according to the path selection result unique principle, and the path calculation result is obtained.
The path calculation method according to claim 4, wherein the path selection in the plurality of path calculation requests is performed according to a path calculation result unique principle, and the step of obtaining the path calculation result comprises:

Performing path calculation on the path options in the plurality of path calculation requests in turn;

If the path calculation performed on the path option in the current path calculation request is successful, the path option that the path calculation succeeds is used as the path calculation result, and the path option in the path calculation request subsequent to the current path calculation request is not Perform path calculations.
The path calculation method according to claim 5, wherein

If the path calculation for the path option in the plurality of path calculation requests fails, the path calculation response indicating that the path calculation fails is sent to the PCC corresponding to the set of synchronization path calculation requests.
The path calculation method according to claim 4 or 5, wherein, after the path calculation result is obtained, the method further comprises the step of performing on the PCE side:

Corresponding to the set of synchronization path calculation requests, a response message including the path calculation result is sent to the PCC.
A path calculation device, wherein the path calculation device is disposed on a PCC side, and includes:

a request establishment module configured to establish a plurality of path calculation requests, the plurality of path calculation requests respectively including corresponding path options;

An association module configured to associate the plurality of path calculation requests into a set of synchronization path calculation requests, so that the PCE can perform path calculation on the path option in the plurality of path calculation requests according to a path calculation result unique principle; and

A PCC transmitting module configured to send the plurality of path computation requests to the PCE.
The path calculation device of claim 8, further comprising:

a PCC receiving module configured to receive, after the PCC sending module sends the multiple path calculation requests to the PCE, a response message sent by the PCE corresponding to the set of synchronization path calculation requests, the response The message includes a path calculation result calculated by the PCE through the path;

A path determination module configured to determine a final path option based on the path calculation result.
The path computing device of claim 9, wherein the path determination module is configured to:

Determining a path calculation request that the path calculation succeeds according to the path calculation result; and

The path option in the path calculation request for which the path calculation is successful is taken as the final path option.
A path calculation device, wherein the path calculation device is disposed on a PCE side, and includes:

a PCE receiving module configured to receive a plurality of path computation requests sent by the PCC, the plurality of path computation requests being associated as a set of synchronization path computation requests;

The path calculation module is configured to perform path calculation on the path option in the plurality of path calculation requests according to a path calculation result unique principle, to obtain a path calculation result.
The path computing device of claim 11 wherein the path computation module is configured to:

Performing path calculation on the path options in the plurality of path calculation requests in turn; and

If the path calculation performed on the path option in the current path calculation request is successful, the path option that the path calculation succeeds is used as the path calculation result, and the path option in the path calculation request subsequent to the current path calculation request is not Perform path calculations.
The path computation device of claim 12, wherein the path computation module is configured to:

If the path calculation for the path option in the plurality of path calculation requests fails, the path calculation response indicating that the path calculation fails is sent to the PCC corresponding to the set of synchronization path calculation requests.
The path calculation device according to claim 11 or 12, further comprising a PCE sending module, wherein the PCE sending module is configured to:

Corresponding to the set of synchronization path calculation requests, a response message including the path calculation result is sent to the PCC.
A PCC comprising the path computing device disposed on the PCC side according to any one of claims 8 to 10.
A PCE comprising a path calculation device disposed on the PCE side according to any one of claims 11 to 14.
A path calculation system comprising the PCC according to claim 15.
A path calculation system comprising the PCE of claim 16.