WO2011050665A1

WO2011050665A1 - Method and device for implementing fast rerouting of ports

Info

Publication number: WO2011050665A1
Application number: PCT/CN2010/076962
Authority: WO
Inventors: 张舒兴
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-11-02
Filing date: 2010-09-15
Publication date: 2011-05-05
Also published as: CN101702683A

Abstract

The present invention discloses a method for implementing the fast rerouting of ports, wherein a switching flag for the original port of a path is set in a port table of a fast rerouting entry. The method includes: when a primary path failure is detected, the value of the switching flag for the original port in the port table which corresponds to the original port of the primary path is set to a value which indicates the failure of the primary path. The present invention also discloses a device for implementing the fast rerouting of ports. With the present invention, the switching speed between the primary path and the backup path can be enhanced.

Description

Method and device for realizing port fast rerouting

The present invention relates to Fast Reroute (FRR) technology, and in particular, to a method and apparatus for implementing fast rerouting of a port. Background technique

The traditional Internet Protocol (IP) network service model is a "best effort" service model. With the further development of network services, the IP network as a multi-service unified bearer must reach the level of traditional telecommunication networks in terms of reliability. If the protection switching speed is less than 50ms, it can meet the needs of carrier-class services.

FRR technology is a technology used to quickly protect local networks. It is generally deployed in networks with high reliability requirements. When a link or node fails in the network, FRR can quickly switch to the alternate path to make the data service less affected.

Currently, there are IP FRR, Label Distribution Protocol (LDP), FRR, and Traffic Engineering (FRR), which exist in IP networks, LDP label networks, and Multiprotocol Label Switching networks. Traffic engineering.

The following describes the flow of the existing FRR switching method. As shown in Figure 1, the flow of the existing FRR switching method includes the following steps:

Step 101: Detect whether the primary path is invalid. If yes, perform step 102; otherwise, continue detecting.

Step 102, notifying that the supporting primary path is invalid.

Steps 103-104, the support determines whether the FRR belongs to the IP FRR, and if yes, performs step 105; otherwise, determines whether the FRR belongs to the LDP FRR, and if yes, performs step 106; otherwise, It can be seen that the FRR belongs to the TE FRR, and step 107 is performed.

Among them, the type of FRR is calculated by the support through a complex hash algorithm.

Step 105: Support to calculate all FRR indexes and FRR groups of the active path according to a complex hash algorithm, and drive the FRR type, the FRR index, the FRR group, and the failed primary next hop notification, and then perform step 108.

The FRR type in this step is IP FRR.

Step 106: Support all the FRR indexes and FRR groups of the active path calculated according to the complex hash algorithm, and drive the FRR type, the FRR index, the FRR group, and the failed primary next hop notification, and then perform step 108.

The FRR type in this step is LDP FRR.

Step 107: Support all the FRR indexes and FRR groups of the active path calculated according to the complex hash algorithm, and drive the FRR type, the FRR index, the FRR group, and the failed primary next hop notification, and then perform step 108.

The FRR type in this step is TE FRR.

Step 108: The driver replaces the failed primary next hop in the FRR entry with the primary next hop according to the FRR type and the FRR index.

Step 109: The driver determines whether all FRR groups are switched over. If yes, step 110 is performed; otherwise, step 111 is performed.

Step 110: The support notification platform generates an alarm; after that, it continues to detect whether the primary path fails.

Among them, the platform is a central processing unit (CPU).

Step 111: The driver acquires the next FRR index that needs to be switched, and returns to step 108. The FRR group has a corresponding relationship with the FRR index.

It can be seen from the above process that the existing FRR switching method relies on the FRR group information of the next hop of the failed active path that is delivered and supported by the existing FRR switching method. It is necessary to switch each FRR group, the process is too cumbersome, and the switching time takes up too much. In particular, when there are more FRR groups, the overhead is larger, which will inevitably affect the completion time of the handover. For example, if 100 FRR groups share one primary link or one link in the primary path, the existing FRR switching method Each FRR group needs to be switched, that is, 100 operations are required to complete all the handovers.

In addition, the invention patent application with the application number of 200410056187.3 discloses a method for implementing re-routing in an IP network, which implements handover by modifying a port table, but the method for detecting whether the port state is valid in the application is limited by the hardware itself. During the detection period, the scan detection period of the general physical port will be greater than 100ms. If the period is too small, the CPU usage resources will be occupied. Thus, the time taken from detecting the port failure to switching is far beyond 50ms, thus failing to meet the telecommunications. The need for a level of business. Summary of the invention

In view of this, the main object of the present invention is to provide a method and apparatus for implementing fast re-routing of a port, which can improve the switching speed of the active and standby paths.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

A method for implementing port fast rerouting, in which a start port switching flag bit of a path is set in a port table of a fast rerouting entry, the method includes:

When it is detected that the primary path fails, the value of the starting port switching flag bit in the port table corresponding to the starting port of the primary path is set to a value indicating that the primary path is invalid.

The method further includes:

When it is detected that the primary link shared by the multiple fast rerouting groups fails, the value of the starting port switching flag bit in the port table corresponding to the primary link starting port is set to a value indicating that the primary path is invalid.

The method further includes: after setting the start port switch flag bit to a value indicating that the active path is invalid, the method further includes: The information of the failed primary path is sent to the support; the information supporting the failed primary path is sent to the platform; and the platform generates an alarm according to the information of the failed primary path.

The method further includes: after setting the start port switch flag bit to a value indicating that the active path is invalid, the method further includes:

The information of the failed primary path is sent to the platform; the platform generates an alarm according to the information of the failed primary path.

The technology used for the detection is a two-way forwarding detection technology or an operation management and maintenance technology.

The value indicating that the primary path fails is 1.

A device for implementing port fast rerouting, comprising: a start port switching flag bit setting module, a detecting module, and a starting port switching flag bit value setting module; wherein

a start port switch flag setting module, configured to set a start port switch flag bit of the path in a port table of the fast reroute entry;

a detecting module, configured to detect a status of the primary path;

The start port switch flag bit value setting module is configured to: when the detecting module detects that the main path fails, set the value of the start port switch flag bit in the port table corresponding to the start port of the main path to indicate that the main switch is used. The value of the path failure.

The start port switching flag bit value setting module is further configured to: when the detecting module detects that the primary link shared by the multiple fast rerouting groups fails, the port table corresponding to the primary link starting port The value of the start port switch flag bit is set to a value indicating that the active path is invalid.

The device further includes: a first information sending module, a support, and a platform; wherein

The first information sending module is configured to send the information of the failed primary path to the support; and the support is used to send the information of the failed primary path to the platform; The platform is configured to generate an alarm according to the information of the failed primary path.

The device further includes: a second information sending module and a platform; wherein, the second information sending module is configured to send the information of the failed primary path to the platform; and the platform is configured to use the failed primary path The information generates an alarm.

It can be seen from the above technical solution that when the primary path is detected to be invalid, the start port switching flag bit in the corresponding port table can be directly taken according to the starting port in the next hop of the failed primary path. The value is set to a value indicating that the primary path has failed, and no changes are required for the alternate next hop. Therefore, through the port fast rerouting technology, when the primary path fails, the failed primary path is switched to the standby path with the fastest speed and the minimum packet loss rate; especially when multiple FRR groups share one master. When the link is used and the primary link fails, the switching operation of the FRR group can be avoided multiple times. Therefore, in this case, the effect of the port fast rerouting technology is more obvious, thereby greatly improving the reliability of the network.

In addition, the present invention can be used in both link protection and node protection networking, and the present invention can be extended to any protection technology in which there are active and standby paths, and the main port can be switched by switching the start port of the active path. Switch to the alternate path with the path. DRAWINGS

FIG. 1 is a schematic flowchart of a conventional FRR switching method;

2 is a schematic flowchart of a method for implementing fast re-routing of a port according to the present invention;

3 is a schematic diagram of switching of multiple FRR groups according to the present invention;

FIG. 4 is a schematic structural diagram of an apparatus for implementing fast re-routing of a port according to the present invention. detailed description

The core idea of the present invention is: When detecting the failure of the primary path, it is not necessary to determine the specific type of FRR, because ultimately it can be attributed to "interface failure", and "interface failure" is directly reflected on the starting port of the primary path. , so "interface failure" means the start of the main path The port is invalid. Therefore, a start port switch flag bit is set in the port table of the FRR entry. When the primary path is detected to be invalid, the value of the start port switch flag bit is set to a value indicating that the primary path is invalid. , indicating that you need to switch to the alternate path, which means that switching the start port means switching between the active and standby paths without distinguishing the type of FRR. The following example shows what is the starting port of the active path: Assume that there are two paths from source port A1 to destination port A4: A1-A2-A3-A4 and A1-B2-B3-A4, the former is used as the primary path. The latter acts as an alternate path, and the starting port of the primary path is A2.

Before explaining the technical solution of the present invention, the difference between "path" and "link" which will be mentioned later is explained: the path refers to the entire path of transmitting data, which includes two or more ports; the link refers to The path between two adjacent ports.

Before implementing the fast re-routing of the port of the present invention, the following steps are required:

An existing FRR entry generally includes a port table and a next hop. The next hop contains the port information of the link. On the basis of this, the start port switch flag of the path is set in the port table of the FRR entry. Here, the start port switch flag is represented by 0 or 1. When the start port switch flag is 1, the active path is invalid and the alternate path is valid. When 0, the active path is normal.

The technical solution for implementing port fast reroute is analyzed by describing the process from the detection of the handover.

When there are two or more different paths to the same destination address, after the FRR is configured, an optimal primary path and an optimal alternate path are formed according to the priority of the path to form an FRR group, or by specifying The mode specifies an active path and an alternate path to form an FRR group. After the FRR group is formed, path detection is configured for the primary path of the FRR group to detect whether the primary path is invalid.

As shown in FIG. 2, the method for implementing port fast rerouting according to the present invention includes the following steps: Step 201: When the detection time is up, detecting whether the primary path is invalid, and if yes, Go to step 202, otherwise, continue testing.

Among them, the detection time can be set as needed.

The detection technology used by the present invention to detect whether the primary path is invalid or not has a BFD (Bidirection Forward Detect) technology or an Operation Administration and Maintenance (OAM) technology, and the like.

Step 202: Determine whether the value of the start port switch flag bit in the port table corresponding to the failed primary path start port is 1, and if yes, return to step 201; otherwise, go to step 203.

Step 203: Set the value of the start port switching flag bit in the port table corresponding to the failed primary path starting port to 1, and send the information of the failed primary path to the support.

After the value of the start port switch flag is set to 1, the port fast re-routing of the present invention is implemented; the following steps are used to generate an alarm.

Step 204: Support the information of the failed primary path to be sent to the platform.

Step 205: The platform generates an alarm according to the information of the failed primary path. After that, the process returns to step 201 to continue the detection.

The content of the alarm includes the failure of the primary path and the switching to the alternate path.

In addition, in order to make the information of the failed primary path more quickly, in step 203, the information of the failed primary path may be directly sent to the platform.

It can be seen from the above process that the present invention does not rely on the FRR group information such as the FRR type and the FRR index that are supported before the handover, and when the primary path is detected to be invalid, the failed primary path can be immediately detected. The starting port in one hop directly sets the value of the starting port switching flag bit in the corresponding port table to 1, and the alternate next hop does not need to be changed. When forwarding data, it is first determined whether the value of the start port switch flag bit in the port table corresponding to the start port of the active path is 1, and if it is 1, the alternate next hop according to the FRR entry is used by the alternate path. Forward; otherwise, forwarded by the primary path. Therefore, unlike the existing FRR switching method, The invention can complete the handover without notifying the support and not relying on the FRR group information supported by the support, the process is quite simple and fast, obviously faster than the existing FRR switching method, and the effect is more in the FRR group, and It is more obvious when the FRR group shares a primary link.

The handover process of multiple FRR groups is described below by way of an embodiment.

As shown in Fig. 3, R1 reaches R31 and there are two paths R1-R20-R31 and R1-R21-R31. To make it clearer, specify the path R1-R20-R31 as the primary path, R1-R21-R31 as the alternate path, and assign the FRR group to FRR1. Similarly, the FRR2 primary path assigned to R32 is R1-R20-R32, the alternate path is R1-R22-R32, the RRR primary path to R33 is R1-R20-R33, and the alternate path is R1-R23-R33; ; The FRRn main path to R3n is Rl-R20-R3n, and the alternate path is Rl-R2n-R3n. Among them, those skilled in the art should understand that R20 is the starting port of each active path, not R1.

FRR uses R1-R20 as the primary link from group 1 to group n. Therefore, the status of the primary link R1-R20 is detected. When the primary link R1-R20 fails (including the case where the initial port R20 fails), the port table corresponding to the primary port R20 of the primary link R1-R20 is used. The value of the middle start port switch flag bit is set to 1, thus implementing one-time switching of multiple FRR groups sharing the primary link, and switching the primary path of each FRR group to the alternate path. The existing FRR switching method needs to switch the n FRR groups separately, and replace the alternate primary hop in each FRR group with the failed primary next hop. Therefore, it is apparent that the present invention greatly improves the switching speed of the active and standby paths than the prior art.

In addition, it should be noted that the time for detecting the BFD technology or the OAM technology used in the present invention is generally about 10 ms, and the time for setting the value of the start port switching flag bit, that is, the time for switching between the active and standby paths, A total of about 20 ms, therefore, the present invention can meet the needs of carrier-class services.

To achieve the above method, the present invention provides a device for implementing fast rerouting of a port, As shown in FIG. 4, the device includes: a start port switching flag bit setting module 10, a detecting module 20, and a start port switching flag bit value setting module 30;

The start port switch flag setting module 10 is configured to set a start port switch flag bit of the path in the port table of the fast reroute entry;

The detecting module 20 is configured to detect a state of the active path;

The start port switching flag bit value setting module 30 is configured to: when the detecting module 20 detects that the main path fails, set the value of the starting port switching flag bit in the port table corresponding to the starting port of the main path to The value of the primary path failure.

The initial port switching flag bit value setting module 30 is further configured to: when the detecting module 20 detects that the primary link shared by the multiple fast rerouting groups fails, the port table corresponding to the primary link starting port is used. The value of the start port switch flag bit is set to a value indicating that the active path is invalid.

The device may further include: a first information sending module, a support, and a platform; wherein, the first information sending module is configured to send the information of the failed primary path to the support; and the support is used to disable the primary path Information sent to the platform;

The platform is configured to generate an alarm according to the information of the failed primary path.

Alternatively, the apparatus may further include: a second information sending module and a platform; wherein, the second information sending module is configured to send the information of the failed primary path to the platform; and the platform is configured to Use the information of the path to generate an alarm.

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

A method for implementing port fast re-routing, which is characterized in that: a start port switch flag bit of a path is set in a port table of a fast re-routing entry, and the method includes:

The method for implementing fast re-routing of a port according to claim 1, wherein the method further comprises:

3. The method for implementing port fast rerouting according to claim 1, wherein after the initial port switching flag bit is set to a value indicating that the primary path fails, the method further includes:

The information of the failed primary path is sent to the support; the information supporting the failed primary path is sent to the platform; and the platform generates an alarm according to the information of the failed primary path.

The method for implementing fast port re-routing according to claim 1, wherein after the initial port switching flag bit is set to a value indicating that the primary path fails, the method further includes:

The method for implementing fast re-routing of a port according to claim 1, 2, 3 or 4, wherein the technology used for the detecting is a bidirectional forwarding detection technology or an operation management and maintenance technology.

The method for implementing fast re-routing of a port according to claim 1, 2, 3 or 4, wherein the value indicating that the primary path fails is 1.

A device for implementing port fast rerouting, the device comprising: a start port switching flag bit setting module, a detecting module, and a starting port switching flag bit value setting module; wherein

a detecting module, configured to detect a status of the primary path;

The apparatus for implementing port fast rerouting according to claim 7, wherein the start port switching flag bit value setting module is further configured to: when the detecting module detects that the plurality of fast rerouting groups are shared When the active link fails, the value of the start port switch flag in the port table corresponding to the start port of the active link is set to the value indicating that the primary path is invalid.

The device for implementing port fast rerouting according to claim 7, wherein the device further comprises: a first information sending module, a support, and a platform;

The first information sending module is configured to send the information of the failed primary path to the support; and the support is used to send the information of the failed primary path to the platform;

The device for implementing port fast rerouting according to claim 7, wherein the device further comprises: a second information sending module and a platform;

The second information sending module is configured to send the information of the failed primary path to the platform, and the platform is configured to generate an alarm according to the information of the failed primary path.