JP2012530412A - Method, device, and system for establishing a backup label switch path - Google Patents

Abstract

  Embodiments of the present invention disclose methods, devices, and systems for establishing a backup label switch path (LSP). The method includes: a step of obtaining path information, a step of performing backup LSP selection according to the path information, and a non-optimal path without a loop path when a non-optimal path without a loop path is selected. The step of using the path as a backup LSP. The present invention implements that the main LSP is tied to the backup LSP and the network negotiates the generation of the backup LSP alone.

Description

  Embodiments of the present invention relate to the field of mobile communication technology, and in particular, to a method, apparatus, and system for establishing a backup label switch path (LSP).

  The Multiprotocol Label Switching (MPLS) protocol is capable of supporting multi-layer labels, is connection-oriented, has excellent extensibility, and therefore has an integrated MPLS / IP-based network architecture that allows clients to It is possible to provide a type of service. MPLS is gradually becoming the basic technology for large networks. As an MPLS protocol, a label distribution protocol (LDP) defined for label distribution is also widely noted.

  LDP is an MPLS control protocol and corresponds to a signaling protocol in a conventional network. LDP is responsible for classifying the same transport class (FEC), distributing labels, and establishing and maintaining LSPs. LSPs established using the LDP protocol include LDP LSPs and pseudowires (PWs).

  When establishing an LSP, the LDP labels by using best and non-optimal paths generated according to the IP routing protocol, or by manually configuring a designated path and thereby establishing the corresponding LSP. Can be distributed. The LDP protocol loop detection mechanism indicates that LDP carries the corresponding path information when distributing the label, detects the path when receiving the path information, and that the generated LSP is loop-free Make sure.

  Fast Re-Route (FRR) is a network fault tolerance policy that can protect links or nodes. When a link or node fails, switching is performed quickly to minimize packet loss. IP FRR protects IP traffic from the IP routing level. That is, the IP routing protocol generates an optimal path and a corresponding backup path so that IP traffic can be switched to the backup path when the optimal path fails.

  In one implementation of the present invention, the inventor has found that the prior art has certain defects. A backup LSP can be established in two ways: one is to manually configure a designated backup path, and the other is to use backup IP routing generated according to the IP FRR algorithm. The former involves a large configuration workload and tedious maintenance, while the latter involves complex algorithms and the solution is not yet mature.

  Embodiments of the present invention provide a method, apparatus, and system for establishing a backup LSP to simply and easily implement the generation of a backup LSP via network self-negotiation.

One embodiment of the present invention provides a method for establishing a backup LSP, including:
Obtaining path information;
Selecting a backup LSP according to the path information;
A step of taking a non-optimal path without a loop path as a backup LSP when a non-optimal path without a loop path is selected.

One embodiment of the present invention provides an apparatus for establishing a backup LSP, including:
An acquisition module configured to acquire path information;
A selection module configured to select a backup LSP according to the path information;
A decision module configured to take a non-optimal path without a loop path as a backup LSP when a non-optimal path without a loop path is selected by the selection module.

  One embodiment of the present invention further provides a system for establishing a backup LSP, including: obtaining path information, selecting a backup LSP according to the path information, and selecting a non-optimal path without a loop path A label switch router configured to take a non-optimal path without its loop path as a backup LSP when

  In the embodiment of the present invention, it is possible to select the non-optimal path without the loop path as the backup LSP according to the path information included in the loop detection information, wherein the loop detection information is acquired in the loop detection process. From the solution it can be known. In this way, the primary LSP and the backup LSP are tied together, thereby making it simple and easy to implement the generation of the backup LSP via network self-negotiation.

  Furthermore, in order to clearly describe the technical solutions in the embodiments of the present invention or in the prior art, the accompanying drawings required for describing the embodiments or the prior art are briefly introduced below. Apparently, the accompanying drawings in the following description are only some embodiments of the present invention, and those skilled in the art can derive other drawings according to these accompanying drawings without creative efforts. .

2 is a schematic flowchart of a method for establishing a backup LSP according to the first embodiment of the present invention; FIG. 7 is a schematic scenario diagram of a plurality of downstream LSRs to which a method for establishing a backup LSP according to the second embodiment of the present invention is applicable. 4 is a schematic flowchart of a method for establishing a backup LSP according to a second embodiment of the present invention; FIG. 10 is a schematic scenario diagram of load distribution to which a method for establishing a backup LSP according to the third embodiment of the present invention is applicable. 7 is a schematic flowchart of a method for establishing a backup LSP according to a third embodiment of the present invention; FIG. 7 is a schematic structural diagram of an apparatus for establishing a backup LSP according to a fourth embodiment of the present invention. FIG. 9 is a schematic structural diagram of an apparatus for establishing a backup LSP according to a fifth embodiment of the present invention. FIG. 10 is a schematic structural diagram of a system for establishing a backup LSP according to a sixth embodiment of the present invention.

  The technical solutions in the embodiments of the present invention will be described below clearly and fully in the embodiments of the present invention with reference to the accompanying drawings. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts are within the protection scope of the present invention.

  In an embodiment of the present invention, LDP FRR is employed to protect MPLS traffic from LDP LSP level. That is, the primary LSP and the corresponding backup LSP are generated according to the LDP protocol so that MPLS traffic can be switched to the backup LSP when the primary LSP fails.

  FIG. 1 is a schematic flowchart of a method for establishing a backup LSP according to the first embodiment of the present invention. As shown in FIG. 1, the method for establishing a backup LSP in this embodiment may include the following steps.

  Step 101: Obtain path information.

  Step 102: Select a backup LSP according to the path information.

  Step 103: When a non-optimal path without a loop path is selected, the non-optimal path without the loop path is taken as a backup LSP.

  The path information acquired in this embodiment can be derived from loop detection information. The loop detection information can include path information. The path information includes identification information regarding a label switch router (LSR) such as an LSR identifier (LSR ID). The LSR ID included in the path information is an identifier of the LSR on the corresponding path. For example, the path information corresponding to the path LSR1 → LSR2 → LSR3 can be expressed as (LSR1, LSR2, LSR3).

  In this embodiment, after acquiring the path information transmitted by the downstream LSR, the upstream LSR can select a non-optimal path without a loop path as the backup LSP according to the path information. In this way, the primary LSP and the backup LSP are tied together, so that the generation of the backup LSP via network self-negotiation can be implemented simply and easily.

  FIG. 2A is a schematic scenario diagram of multiple downstream LSRs where the method of establishing a backup LSP is applicable according to the second embodiment of the present invention. In this scenario, the LSRB upstream LSR is LSRA. The LSRB has two downstream LSRs: LSRC and LSRD. The LSRC downstream LSR is also LSRD. Therefore, two paths exist from LSRB to LSRD. One is LSRB → LSRC → LSRD, and the other is LSRB → LSRD. In the above two paths, LSRB → LSRD can be determined as the optimum path according to the IP routing protocol.

  FIG. 2B is a schematic flowchart of a method for establishing a backup LSP according to the second embodiment of the present invention. As shown in FIG.2B, the method of establishing a backup LSP in this embodiment may include:

  201: Each LSRB obtains loop detection information transmitted by two downstream LSRs, namely LSRC and LSRD. The loop detection information transmitted by the LSRC includes corresponding path information (LSRC, LSRD), and the loop detection information transmitted by the LSRD includes corresponding path information (LSRD).

  At this step, a loop detection function of label distribution protocol (LDP) signaling can be used to obtain loop detection information via a label mapping message, and the destination is LSRD.

  202: The LSRB selects a backup LSP according to the acquired two path information.

  203: When a non-optimal path LSRB → LSRC → LSRD is selected, where there is no loop path and the path information is (LSRC, LSRD), the LSRB backs up the non-optimal path LSRB → LSRC → LSRD without the loop path Take as.

  In this step, neither the optimum path LSRB → LSRD whose path information is (LSRD) nor the non-optimal path LSRB → LSRC → LSRD whose path information is (LSRC, LSRD) has a loop path. The optimal path LSRB → LSRD whose path information is (LSRD) is the primary LSP. Therefore, the LSRB selects a non-optimal path LSRB → LSRC → LSRD having no loop path and having the path information (LSRC, LSRD) as the backup LSP according to the path information (LSRC, LSRD) and (LSRD).

  204: The LSRB binds the primary LSP and the backup LSP.

  In this embodiment, the upstream LSRB selects a non-optimal path without a loop path as a backup LSP according to the path information included in the loop detection information transmitted by the downstream LSRC and the downstream LSRD and acquired in the loop detection process. sell. To implement LDP FRR, LSRB is a primary LSP whose path information is (LSRD) and a backup LSP whose path information is (LSRC, LSRD), that is, LSRB → LSRD and LSRB → LSRC → LSRD, Tie. When the primary LSP fails, the LSRB can switch traffic to the backup LSP in time, thereby simply and easily implementing backup LSP generation via network self-negotiation.

  Furthermore, the LSRB in this embodiment can further transmit the path information acquired to the upstream LSR, that is, LSRA. Specifically, the LSRB may be as follows.

  205A: The LSRB sends path information (LSRB, LSRD) about the optimal path to the upstream LSRA, or

  205B: LSRB sends path information (LSRB, LSRC, LSRD) about non-optimal path to upstream LSRA, or

  205C: LSRB sends path information (LSRB, LSRD) about the optimal path and corresponding optimal identification information, and path information (LSRB, LSRC, LSRD) about the non-optimal path and corresponding non-optimal identification information to the upstream LSRA To do.

  Note that in this embodiment, when the LSRC sends path information to the LSRB, the situation where the LSRC also has other downstream LSRs is not considered. If the LSRC also considers situations with other downstream LSRs, the loop detection information sent by the LSRC may further include information on the corresponding multiple paths. More specifically, a reference to the acquired path information transmitted by LSRB to LSRA, which is not described herein again, can be made.

  FIG. 3A is a schematic scenario diagram of load distribution to which a method for establishing a backup LSP according to the third embodiment of the present invention is applicable. In this scenario, the LSRE has two downstream LSRs: LSRH and LSRF. The downstream LSR of the LSRF is LSRG. The downstream LSR of LSRG is LSRH. Thus, two paths exist from LSRE to LSRH. One is LSRE → LSRF → LSRG → LSRH, and the other is LSRE → LSRH. In the above two paths, LSRE → LSRH can be determined as the optimum path according to the IP routing protocol.

  FIG. 3B is a schematic flowchart of a method for establishing a backup LSP according to the third embodiment of the present invention. As shown in FIG.3B, the method of establishing a backup LSP in this embodiment may include:

  301: Each LSRE obtains loop detection information transmitted by two downstream LSRs, namely LSRH and LSRF. The loop detection information transmitted by LSRH includes the corresponding path information (LSRH), and the loop detection information transmitted by LSRF includes the corresponding two path information (LSRF, LSRE, LSRH) and (LSRF, LSRG, LSRH). Including.

  In this step, the loop detection function of LDP signaling can be used to obtain loop detection information via a label mapping message and the destination is LSRH.

  302: The LSRE selects a backup LSP according to the acquired three path information.

  303: When non-optimal path LSRE → LSRF → LSRG → LSRH is selected without a loop path and its path information is (LSRF, LSRG, LSRH), LSRE is a non-optimal path LSRE → LSRF without a loop path as a backup LSP → Take LSRG → LSRH.

  In this step, the non-optimal path LSRE → LSRF → LSRE → LSRH whose path information is (LSRF, LSRE, LSRH) has a loop path, and the optimal path LSRE → LSRH and its path information whose path information is (LSRH) The non-optimal path LSRE → LSRF → LSRG → LSRH with (LSRF, LSRG, LSRH) has no loop path, and the optimal path LSRE → LSRH with the path information (LSRH) is the primary LSP . Therefore, according to its path information (LSRH), (LSRF, LSRE, LSRH), and (LSRF, LSRG, LSRH), LSRE has no loop path and its path information is (LSRF, LSRG, LSRH) The path LSRE → LSRF → LSRG → LSRH is selected as the backup LSP.

  304: The LSRE binds the primary LSP and the backup LSP.

  In this embodiment, the upstream LSRE selects a non-optimal path without a loop path as a backup LSP according to the path information included in the loop detection information transmitted by the downstream LSRF and the downstream LSRH and obtained in the loop detection process. be able to. The LSRE is sent by the downstream LSRH to implement the LDP FRR, the primary LSP whose path information is (LSRH) and the backup LSP whose path information is (LSRF, LSRG, LSRH), i.e. Connect LSRE → LSRH and LSRE → LSRF → LSRG → LSRH. When the primary LSP fails, the LSRE can switch traffic to the backup LSP in time, thereby simply and easily implementing backup LSP generation via network self-negotiation.

  In this embodiment, when the LSRF sends path information to the LSRE, the situation where the LSRF also has other downstream LSRs is not considered. If the situation where the LSRF also has other downstream LSRs is considered, the loop detection information transmitted by the LSRF may further include information on the corresponding multiple paths. Specifically, it is possible to refer to the acquired path information transmitted to the LSRA by the LSRB in the above embodiment, which is not described again in this specification.

  In addition, to avoid the problem of the existence of loops, the LSRE in this embodiment further includes the primary to the LSR on the backup LSP after the LSRE has determined the coupling relationship between the primary LSP and the backup LSP. / Backup relationship, that is, connection relationship can be notified. For example, the LSRE may pass path information (LSRF, LSRF, LSRG, LSRH) can be sent to LSRF and LSRG. In this way, loop paths are avoided and network performance is improved.

  For ease of explanation, all of the foregoing method embodiments are represented as a series of operation combinations, but the invention is not limited to the described operation sequence, and according to the invention, several steps It should be noted that those skilled in the art will understand that can be performed in other orders or simultaneously. It will also be appreciated by those skilled in the art that all of the embodiments described herein are exemplary embodiments, and that related operations and modules are not necessarily required for the invention.

  In the above-described embodiment, the description of each embodiment emphasizes itself, and for a part not detailed in the specific embodiment, reference can be made to related descriptions in other embodiments.

  FIG. 4 is a schematic structural diagram of an apparatus for establishing a backup LSP according to the fourth embodiment of the present invention. As shown in FIG. 4, the apparatus for establishing a backup LSP in this embodiment may include an acquisition module 41, a selection module 42, and a determination module 43. The acquisition module 41 acquires path information. The selection module 42 selects a backup LSP according to the path information. When a non-optimal path without a loop path is selected by the selection module 42, the determination module 43 takes the non-optimal path without the loop path as a backup LSP.

  The method described in the first embodiment of the present invention, the function of the LSRB in the second embodiment of the present invention, and the function of the LSRE in the third embodiment of the present invention are provided in this embodiment. Everything can be done with a device that establishes a backup LSP.

  The path information acquired by the acquisition module 41 in this embodiment can be derived from loop detection information. The loop detection information can include path information. The path information may include identification information related to LSR, for example, an LSR identifier (LSR ID). The LSR ID included in the path information is the LSR identifier of the corresponding path. For example, the path information corresponding to the path LSR1 → LSR2 → LSR3 can be expressed as (LSR1, LSR2, LSR3).

  In this embodiment, after the acquisition module acquires the path information, the determination module determines that the non-optimal path without the loop path is selected by the selection module according to the path information acquired by the acquisition module. Take the best path as a backup LSP. Finally, the combining module can further combine the primary LSP and the backup LSP, thereby simply and easily implementing the generation of the backup LSP via network self-negotiation.

FIG. 5 is a schematic structural diagram of an apparatus for establishing a backup LSP according to the fifth embodiment. As shown in FIG. 5, compared to the previous embodiment, the apparatus for establishing a backup LSP in this embodiment may further include a transmission module 51 that is specifically configured to:
Sending path information about the best path to the upstream LSR, or
Sending path information about the non-optimal path to the upstream LSR, or
Transmitting path information related to the optimal path and corresponding optimal identification information, and path information related to the non-optimal path and corresponding non-optimal identification information to the upstream LSR.

  Furthermore, in order to avoid the problem of the existence of a loop, the apparatus establishing the backup LSP in the fourth or fifth embodiment of the present invention further notifies the primary / backup related backup LSP to all LSRs. A notification module (not shown) configured to do so may be included. In this way, loop paths are avoided and network performance is improved.

  FIG. 6 is a schematic structural diagram of a system for establishing a backup LSP according to the sixth embodiment of the present invention. As shown in FIG. 6, the system for establishing a backup LSP in this embodiment acquires path information, selects a backup LSP according to the path information, and when a non-optimal path without a loop path is selected, An LSR 61 configured to take a non-optimal path without a loop path as a backup LSP may be included.

  The method described in the first embodiment of the present invention, the function of the LSRB in the second embodiment of the present invention, and the function of the LSRE in the third embodiment of the present invention are provided in this embodiment. All can be implemented by the LSR 61 in a system that establishes a backup LSP. The LSR 61 may be an apparatus for establishing a backup LSP provided in the fourth or fifth embodiment of the present invention.

  In this embodiment, the path information acquired by the LSR 61 can be derived from the loop detection information. The loop detection information can include path information. The path information may include identification information regarding the LSR, for example, an LSR identifier (LSR ID). The LSR ID included in the path information is an identifier of the LSR on the corresponding path. For example, the path information corresponding to the path LSR1 → LSR2 → LSR3 can be expressed as (LSR1, LSR2, LSR3).

  In this embodiment, after acquiring path information, the LSR takes a non-optimal path without a loop path as a backup path when a non-optimal path without a loop path is selected according to the acquired path information. Finally, the primary LSP and backup LSP can be further combined, thereby simply and easily implementing backup LSP generation via network self-negotiation.

  Note that the LSPs in the foregoing embodiments of the invention may include, but are not limited to, LDP LSPs and PWs.

  One skilled in the art can appreciate that all or part of the steps of the foregoing method embodiments can be implemented by a program that instructs the associated hardware. The program can be stored in a computer-readable storage medium. When the program runs, the steps of the foregoing method embodiment are performed. The storage medium may include any medium capable of storing program code, such as a ROM, RAM, magnetic disk, or compact disk.

  Finally, it should be noted that the foregoing embodiments are merely used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the previous embodiments, modifications to the technical solutions described in the previous embodiments are possible, and equivalent replacements are possible for some of the technical solutions. Those skilled in the art will appreciate that this can be done to the technical features of However, these modifications or replacements do not form the essence of corresponding technical solutions that depart from the spirit and scope of the technical solutions in the embodiments of the present invention.

41 Acquisition module
42 Selection module
43 Decision Module
51 Transmission module
61 Label Switch Router (LSR)

Claims (11)

A method of establishing a backup label switch path (LSP),
Obtaining path information;
Selecting a backup LSP according to the path information;
Taking a non-optimal path without a loop path as a backup LSP when a non-optimal path without a loop path is selected.   The step of acquiring the path information includes the step of acquiring loop detection information by using a loop detection function of a label distribution protocol (LDP) via a label mapping message, and the path information corresponding to the loop detection information is obtained. 2. The method of claim 1, comprising. The path information is
Path information about the best path sent by the downstream label switch router (LSR), or
Path information about the non-optimal path sent by the downstream LSR, or
The method of claim 1, comprising: path information and corresponding optimal identification information regarding the optimal path transmitted by the downstream LSR; and path information and corresponding non-optimal identification information regarding the non-optimal path transmitted by the downstream LSR. . Sending path information regarding the best path to an upstream LSR, or
Sending path information regarding the non-optimal path to an upstream LSR, or
The method according to claim 3, further comprising: transmitting path information regarding the optimal path and corresponding optimal identification information, and path information regarding the non-optimal path and corresponding non-optimal identification information to an upstream LSR.   5. The method according to claim 1, further comprising a step of transmitting path information regarding the backup LSP to the LSR on the backup LSP after the step of taking the non-optimal path without the loop path as a backup LSP. The method according to one item. An acquisition module configured to acquire path information;
A selection module configured to select a backup LSP according to the path information;
Establishing a backup label switch path (LSP) comprising a decision module configured to take a non-optimal path without the loop path as a backup LSP when a non-optimal path without a loop path is selected by the selection module Device to do.   The acquisition module is specifically configured to acquire loop detection information comprising corresponding path information by using a label detection protocol (LDP) loop detection function via a label mapping message. 6. The device according to 6. Send path information about the best path to the upstream label switch router (LSR), or
Sending path information regarding non-optimal paths to the upstream LSR, or
Further comprising: a transmission module configured to transmit the path information related to the optimal path and the corresponding optimum identification information, and the path information related to the non-optimal path and the corresponding non-optimal identification information to the upstream LSR. The apparatus according to claim 6.   9. The apparatus according to any one of claims 6, 7, or 8, further comprising a notification module configured to send path information regarding the backup LSP to the LSR on the backup LSP.   A label switch configured to acquire path information, select a backup LSP according to the path information, and take a non-optimal path without the loop path as a backup LSP when a non-optimal path without a loop path is selected A system that establishes a backup label switch path (LSP) with a router (LSR).   Specifically, the LSR uses the label distribution protocol (LDP) loop detection function via a label mapping message to obtain loop detection information including corresponding path information, and performs backup LSP according to the path information. 11. The system of claim 10, configured to select and select a non-optimal path without a loop path as a backup LSP when a non-optimal path without a loop path is selected.

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