WO2011017900A1 - Segment protection method and system for ethernet tunnel - Google Patents

Abstract

A segment protection method and system for Ethernet tunnel are disclosed by the present invention, and used for solving the technical problems, such as the traffic congestion due to the network traffic burst, or the like. In the present invention, a work segment has M protection segments as the protection, and the normal operation of the network still can be ensured when the failures of multiple links occur, and the reliability of the network is improved. A Backup Port Table (BPT) is configured for each Infrastructure Protection Group (IPG), the backup egresses of different Traffic Engineering Service Instances (TESIs) in each BPT are set different priorities, when the traffic switch occurs in IPG, each of traffics can be switched to different protection segments, and therefore load sharing on the protection segments can be realized. The BPT configured for the IPG includes the information of the TESIs protected by the IPG, so a group of TESIs can be protected at the same time, it overcomes the abuse that all passing TESIs are switched when performing switch in the link protection, so the flexibility of the network configuration is advanced.

Description

 Ethernet tunnel branching protection method and system

 The present invention relates to the field of data communications, and in particular, to an Ethernet tunnel segmentation protection method and system. Background technique

With the concept of carrier-grade Ethernet, in order to make Ethernet reach the telecom level standard, higher requirements are placed on the protection and switching of Ethernet. In the existing Provider Backbone Bridge Traffic Engineering (PBB-TE) protection switching technology that supports traffic engineering, the current support for Traffic Engineering Service Instance (TESI) is protected. Protection is an end-to-end tunnel protection. This end-to-end protection scheme not only protects the switching time, but also involves too many nodes and lacks protection for intermediate links and nodes. Once a link or a node in the middle fails, the entire TESI must be switched, and if there are multiple TESIs on the faulty link or the faulty node, multiple TESIs will be switched. That is to say, the protection object of the PBB-TE end-to-end protection is TESI. When it is detected that a certain working TESI is faulty, the user message entering the PBB-TE tunnel needs to be re-encapsulated with another protection TESI to let the traffic Take the protection of the PBB-TE tunnel. For Ethernet, link and node protection are part of Ethernet protection. Most network failures occur on a certain link or node, so PBB-TE segmentation protection becomes more urgent. A number of operators have proposed a segmentation protection requirement for PBB-TE, that is, a section of the PBB-TE tunnel is specially configured with a protection segment to protect this segment. The current general practice is 1: 1 PBB. - TE segment protection, as shown in Figure 1, that is, a protection group has a working segment and a protection segment. Under normal circumstances, all of the PBB-TE segment protection groups The protected traffic is forwarded from the working segment. However, when the working segment fails, the PB-TE segment protection zone endpoint SEB (Segment Edge Bridge) can detect the fault in time, and the trigger forwarding table will be affected. The egress port of the forwarding table corresponding to the TESI protected by the protection zone is modified to be the egress port corresponding to the protection segment, so that the traffic is switched to the protection segment, thereby realizing the protection of the working segment, ensuring normal forwarding of network traffic, and improving The reliability of the network. However, in some cases, the 1:1 protection of the package is not enough. Sometimes there are some natural causes of the link and human-induced damage. At this time, the PBB-TE of M:l can be introduced for the link part that is particularly important. Segment protection, that is, in a M:l PBB-TE segment protection group, there is a working segment and M protection segments, and M protection segments protect a working segment, further improving the reliability of the system.

 However, it is unscientific to make the M protection segments idle and wait for the protection switch to be uneconomical. In order to make full use of network resources, in many cases, the M protection segments will also be link members of other PBB-TE segment protection groups: it may be the working segment of other PBB-TE segment protection groups, or it may be other The PBB-TE segment protects the protection segments of the group, so they may also carry other traffic. If all the traffic on the working segment is switched to one of the protection segments after the working segment of the PBB-TE segment protection group of the M:1 fails, the traffic on the protection segment may be too large and cause congestion. Therefore, the traffic can be distributed to different M protection segments when the work segment is faulty. Summary of the invention

 In view of the above, the main purpose of the present invention is to provide a method and system for load balancing of Ethernet tunnel segmentation protection, which is used to solve technical problems such as traffic congestion caused by network traffic bursts, and the present invention implements PBB-TE. At the same time of segment protection, load sharing is implemented when traffic is switched to the protection segment. In order to achieve the above object, the technical solution of the present invention is achieved as follows:

 An Ethernet tunnel segmentation protection method includes:

For the Carrier Backbone Bridging (PBB-TE) Protection Group (IPG) supporting traffic engineering with multiple protection segments and one working segment, configure the inclusion flow on the segment edge bridge (SEB) of the IPG. An alternate port table (BPT) of the correspondence between the quantity engineering service instance (TESI) and the corresponding outbound port of the protection segment on its SEB;

 When the traffic protected by the IPG is switched to the protection segment, the BPT table is queried to obtain an alternate egress port of each TESI, and the egress port of the corresponding entry in the forwarding table is updated to the alternate egress port obtained by querying the BPT table. , thus achieving IPG traffic switching.

 Further, in the BPT, each TSI protected by the IPG corresponds to a different set of standby egress ports, the different standby egress ports are set with different priorities, and the spare egress ports with high priority are in the When the IPG switches to the protection segment, it is preferentially selected.

 Further, the method for updating the egress port of the corresponding entry in the forwarding table to the alternate egress port obtained by querying the BPT table is specifically:

 When the SEB of the IPG detects that the working segment is faulty and needs to be switched, the SEB first queries the BPT, traverses each TESI protected by the IPG, and finds the highest priority standby corresponding to each TESI. Port, and then replace the egress port of each TESI corresponding forwarding table entry.

 Further, the method further includes: a processing step of the backup port corresponding to the protection segment in the BPT table, specifically:

 When a certain protection segment in the IPG fails, the priority of the alternate outgoing port corresponding to the protection segment in the BPT table is minimized for each TESI; correspondingly, in the failed When the protection segment returns to normal, the priority of the alternate egress port corresponding to the protection segment in the BPT table is restored to the original value.

 Further, the value of the standby out port is reduced to the lowest value or restored to the original value by inverting the priority of the spare out port.

Based on the foregoing method, the present invention further provides an Ethernet tunnel segmentation protection system, including: a configuration module, is used for carrier backbone bridge support (PBB-TE) supporting traffic engineering with multiple protection segments and one working segment. IPG (IPG) protection domain endpoint (SEB) configuration includes a backup port table (BPT) and a forwarding table of a correspondence between a traffic engineering service instance (TESI) and a backup outbound port corresponding to the protection segment on the SEB;

 a switching module, configured to query the BPT to obtain an alternate egress port when the traffic protected by the IPG is switched to the protection segment, and update an egress port of the corresponding entry in the forwarding table to an alternate egress port obtained by querying the BPT table; Performing the IPG to switch to the protection segment.

 Further, the configuration module allocates different standby outgoing ports for each of the BPTs that are protected by the IPG, and sets different priorities for different standby outgoing ports; the switching module updates the forwarding table. When the egress port of the corresponding entry is selected, the alternate egress port with the highest priority is preferentially selected.

 Further, the switching module includes:

 The switching detection module is configured to detect whether the working segment is faulty, and if yes, notify the forwarding table to refresh the module;

 And a forwarding table refreshing module, configured to: when the working segment is faulty, traverse each TSI in the BPT that is protected by the IPG, find an alternate outbound port with the highest priority corresponding to each TESI, and then replace each TESI corresponding Outbound port of the forwarding table entry;

 The switching execution module is configured to perform traffic switching according to the forwarding table.

 Further, the switching module further includes:

 a link priority monitoring module, configured to: when a certain protection segment of the IPG is faulty, reduce a priority of the standby outbound port corresponding to the protection segment in the BPT table to a minimum for each TESI; And returning the priority of the spare egress port corresponding to the protection segment in the BPT table to the original value when the faulty protection segment returns to normal.

 Further, the link priority monitoring module reduces its value to the lowest value or restores the original value by inverting the priority of the standby outgoing port.

After the PBB-TE segmentation protection method of the M:1 according to the present invention is used, since there are M protection segments for one working segment as protection, the network can still be guaranteed in the case of failure of multiple links. The normal operation of the network, thus greatly improving the reliability of the network; since each IPG is configured with a backup port table BPT, different priority ports of different TESIs in each BPT can be set, so when the IPG is switched, The traffic can be switched to different protection segments to implement load sharing in the protection segment. In addition, since the BPT configured for the IPG contains the information of the TESI protected by the IPG, it can be protected against a group of TESIs. It overcomes the disadvantages of switching all the passed TESIs during the link protection during handover, thereby improving the flexibility of network configuration and protection. DRAWINGS

 1 is a schematic diagram of a PBB-TE segmentation protection method in the prior art;

 2 is a schematic diagram of a flow rate according to an embodiment of the present invention;

 3 is a schematic diagram of traffic switching after a working segment fails in the embodiment of the present invention; FIG. 4 is a schematic diagram of a BPT table configured in an embodiment of the present invention;

 FIG. 5 is a flowchart of querying a BPT after a fault occurs in a working segment according to an embodiment of the present invention; FIG. 6 is a schematic diagram of a fault in a protection segment according to an embodiment of the present invention;

 FIG. 7 is a schematic diagram of a BPT table after a certain protection segment fails in the embodiment of the present invention; FIG. 8 is a logical structural diagram of the system according to the present invention. detailed description

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

 In this embodiment, a PBB-TE segmentation protection of 2:1 (i.e., M = 2) is taken as an example to illustrate the specific implementation of the present invention:

As shown in Figure 2, for the PBB-TE Segment Protection Group (IPG), there is one working segment and two protection segments. The traffic protected by this IPG is TESI1, TESI2, TESI3, TESI4. Once the working segment fails, TESI1, TESI2 and TESI3, TESI4 are protected by the IPG. Do not switch to protection segment 1 and protection segment 2. As shown in Figure 3, TESI1 and TESI2 are switched to protection segment 1, and TESI3 and TESI4 are switched to protection segment 2. Thereby, load sharing of traffic during protection switching is achieved.

 The working segment in the present invention refers to a segment in which the traffic passes when the segment does not detect the occurrence of the fault, and the protection segment refers to a segment that carries traffic after detecting the failure of the working segment or the switching of the management command that receives the handover, the segment It refers to a network link consisting of a local area network (LAN) and a bridge between a series of carrier network ports (PNPs) and PNP ports.

 In this embodiment, a BPT table (Backup Port Table) is configured for the IPG in the network planning configuration. In the table, each corresponding IPSI protected TESI is configured with a different backup. Different priorities of the outgoing ports. In this example, the BPT table is as shown in FIG. 4, that is, each TSI protected by the IPG corresponds to a different standby egress port, and the priority of each spare egress port is different, for example, TESI1 corresponds to the alternate egress port 2 priority. The level is P1, and TESI1 corresponds to the standby outgoing port 3 with priority P2, where P1 priority is higher than P2 priority. When the network is working normally, TESI1, TESI2, TESI3, and TESI4 all go through the working segment. When the two endpoints of the IPG, SEB1 and SEB2, detect a failure on the working segment, an action is performed to switch the traffic to the protection segment (the mapDataToProtection process).

 The SEB of the present invention is used for the two endpoints of the terminating segment. The SEB may be a Backbone Edge Bridge (BEB) device in the PBB-TE network, or may be a Backbone Core Bridge. BCB) equipment. The IPG traffic switching refers to redirecting a group of TESI traffic protected by the IPG from a walking working segment to a walking protection segment, or from a walking protection segment to a walking working segment. The redirection is implemented by modifying the egress port corresponding to the corresponding entry in the forwarding table.

FIG. 5 is a flowchart of steps for implementing IPG traffic switching according to the present invention. The specific steps are as follows: Step 101: Obtain a record from a BPT table, where the record includes TESI as shown in FIG. The identifier and the priority of the corresponding outgoing port;

 Step 102: Query, according to the TESI identifier, an alternate outbound port with the highest priority corresponding to each TESI;

 Step 103: Update the forwarding table, and update the egress port in each forwarding entry corresponding to the IPG-protected TESI in the forwarding table to the standby with the highest priority corresponding to the TESI found in the BPT table. port.

 Step 104: Determine whether the BPT table traversal is completed. If not, go to step 101; otherwise, end the processing of mapDataToProtection and protect the switching action.

 Before the outbound port with the highest priority of each TESI is queried and the egress port of the corresponding entry in the forwarding table is updated with the port, the protection segment to which the standby egress port belongs is guaranteed to be fault-free. If the status of the egress port is determined after querying an alternate egress port in the BPT table, the speed of the handover will be reduced. In particular, if the status of the port indicates that the link to which the link belongs has failed, You need to re-query the BPT table to find the next available spare port. This will greatly reduce the switching speed and affect the performance of the network.

 Therefore, in order to improve the speed of the BPT lookup table, the present invention also provides a method for improving the BPT lookup table speed and optimizing the protection switching performance, that is, in the process of checking the table, the state of the spare out port that is queried is not judged one by one. On the other hand, in the process of detecting the protection segment, the SEB detects the failure of the protection segment, and then modifies the BPT table, and reduces all priorities of the backup port corresponding to the protection segment in the BPT table, for example, The priority is reversed. Further, if it is detected that the protection segment is restored, the BPT table is modified again, and all the priority ports of the standby egress port corresponding to the protection segment are reversed again, that is, after the protection segment recovers from the failure, the BPR table is restored. Original priority. Therefore, it is guaranteed that the alternate outgoing port that has failed will not be selected when the alternate outgoing port is selected during the traffic switching process. At the same time, the standby port can participate in the selection process according to the priority of the previously set standby port after the fault is recovered.

In this embodiment, when the protection segment 1 and the protection segment 2 are not faulty, the BPT of the IPG to which it belongs is The table is shown in Figure 4. If the protection segment 1 fails, as shown in Figure 6, both SEB1 and SEB2 can detect the fault, and then modify the respective BPT table to prioritize the backup outbound port 2 corresponding to the protection segment 1 in the BPT table. Inverted, as shown in Figure 7, thereby reducing the priority corresponding to the alternate outgoing port 2 to a minimum. Therefore, when the BPT table is queried after the fault occurs in the working segment, the standby outgoing port is not queried, for example, the standby outgoing port 2 in FIG. 7 is not found. Once SEB1 and SEB2 detect the failure recovery of protection segment 1, the BPT table will be updated again, and the priority corresponding to the alternate outgoing port 2 will be reversed again, the effect is to restore its original priority level, and the restored BPT table is again Returning to the state shown in Figure 4, it is possible to normally participate in checking the BPT table for priority comparison to filter out the highest priority alternate outgoing port.

 8 is a schematic diagram of a logical structure of an Ethernet tunnel segmentation protection load sharing system according to the present invention, including a configuration module and a switching module. The configuration module includes an alternate port table BPT and a forwarding table, and the switching module includes a switching detection module and a forwarding table refresh module. , switching execution module and link priority monitoring module.

 The configuration module is configured to configure, on the segment edge bridge SEB of the PBB-TE segment protection group IPG having multiple protection segments and one working segment, between the traffic engineering service instance TESI and the protection segment corresponding to the standby out port on the SEB. The alternate port table BPT and the forwarding table of the corresponding relationship; the configuration module allocates different standby outgoing ports for each of the BPTs that are protected by the IPG, and sets different priorities for different standby outgoing ports; When the module updates the egress port of the corresponding entry in the forwarding table, the module preferentially selects the alternate egress port with a higher priority.

 The switching module is configured to query the BPT to obtain an alternate egress port when the traffic protected by the IPG is switched to the protection segment, and update the egress port of the corresponding entry in the forwarding table to the standby egress port obtained by querying the BPT table; The IPG switches to the protection segment.

The switching detection module in the switching module is configured to detect whether the working segment is faulty, and if yes, notify the forwarding table refreshing module; the forwarding table refreshing module is configured to traverse each of the BPTs to be protected by the IPG when the working segment is faulty TESI, find the highest priority for each TESI The alternate outgoing port is then replaced with the outgoing port of each forwarding table entry corresponding to the TESI; finally, the switching execution module performs link switching according to the forwarding table.

 The link priority monitoring module is configured to: when a certain protection segment in the IPG fails, minimize the priority of the standby outbound port corresponding to the protection segment in the BPT table for each TESI; and in the failure When the protection segment returns to normal, the priority of the alternate outgoing port corresponding to the protection segment in the BPT table is restored to the original value.

 The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim  An Ethernet tunnel segmentation protection method, comprising:  For the Carrier Backbone Bridging (PBB-TE) Segment Protection Group (IPG) that supports multiple traffic segments and one working segment to support traffic engineering, configure a traffic engineering service instance on the segment edge bridge (SEB) of the IPG ( TESI) and an alternate port table (BPT) of the correspondence between the corresponding outgoing ports of the protection segment on its SEB;  When the traffic protected by the IPG is switched to the protection segment, the BPT table is queried to obtain an alternate egress port of each TESI, and the egress port of the corresponding entry in the forwarding table is updated to the alternate egress port obtained by querying the BPT table. , to achieve segment switching.  2. The method according to claim 1, wherein in the BPT, each TSI protected by the IPG corresponds to a different set of standby egress ports, and the different alternate egress ports are set with different priorities. The priority outgoing port with a higher priority is preferentially selected when the IPG switches to the protection segment.  The method according to claim 2, wherein the updating of the egress port of the corresponding entry in the forwarding table to the alternate egress port obtained by querying the BPT table is specifically:  When the SEB of the IPG detects that the working segment is faulty and needs to be switched, the SEB first queries the BPT table, traverses each TESI protected by the IPG, and finds the highest priority standby corresponding to each TESI. Port, and then replace the egress port of each TESI corresponding forwarding table entry.  The method according to claim 3, wherein the method further includes: processing the backup port corresponding to the protection segment in the BPT table, specifically: When a certain protection segment in the IPG fails, the priority of the alternate outgoing port corresponding to the protection segment in the BPT table is minimized for each TESI; correspondingly, the failure protection is performed. When the segment returns to normal, the priority of the alternate outgoing port corresponding to the protection segment in the BPT table is restored to the original value. 5. The method according to claim 4, wherein the value of the standby out port is reduced to a minimum value or restored to an original value by a method of inverting the priority of the spare out port.  6. An Ethernet tunnel segmentation protection system, comprising:  A configuration module for configuring traffic engineering services on a segment edge bridge (SEB) of a carrier backbone bridge (PBB-TE) segment protection group (IPG) supporting traffic engineering with multiple protection segments and one working segment An alternate port table (BPT) and a forwarding table of an instance (TESI) and a correspondence between the corresponding outgoing ports of the protection segment on its SEB;  And a switching module, configured to query the BPT table to obtain an alternate egress port when the traffic protected by the IPG is switched to the protection segment, and update an egress port of the corresponding entry in the forwarding table to an alternate egress port obtained by querying the BPT table. ; Perform the IPG to switch to the protection segment.  The system according to claim 6, wherein the configuration module allocates different standby outgoing ports for each of the BPTs that are protected by the IPG, and sets different priorities for different standby outgoing ports. The switching module preferentially selects an alternate outgoing port with a higher priority when updating the egress port of the corresponding entry in the forwarding table.  The system according to claim 7, wherein the switching module comprises: a switching detection module, configured to detect whether a working segment is faulty;  And a forwarding table refreshing module, configured to: when the working segment is faulty, traverse each TSI in the BPT that is protected by the IPG, find an alternate outbound port with the highest priority corresponding to each TESI, and then replace each TESI corresponding Outbound port of the forwarding table entry;  The switching execution module is configured to perform traffic switching according to the forwarding table. The system according to claim 8, wherein the switching module further comprises: a link priority monitoring module, configured to: when a certain protection segment in the IPG fails, for each TESI, The priority of the standby egress port corresponding to the protection segment in the BPT table is minimized; and when the failed protection segment returns to normal, the priority of the backup egress port corresponding to the protection segment in the BPT table is prioritized The level is restored to its original value. 10. The system according to claim 9, wherein the link priority monitoring module reduces its value to a minimum or restores the original value by inverting the priority of the standby outgoing port.