WO2012068907A1 - Method and device for determining forwarding path in pw dual homing protection environment - Google Patents

Abstract

Disclosed are a method and a device for determining a forwarding path in a PW dual homing protection environment, which belong to the field of network communication technologies. When a forwarding apparatus receives a message, an MAC address of the message is obtained, and a forwarding path index and a dual homing protection mark corresponding to the MAC address are obtained; according to the dual homing protection mark, it is determined whether PW dual homing protection switching occurs in an outlet PW, and if yes, a current effective path is determined through a PW dual homing protection list, and according to the forwarding path index, an index of the effective path is obtained from the PW dual homing protection list; a PW forwarding path is acquired from a PW forwarding list by using the index of the effective path. The method and the device of the present invention are only required to modify active and standby states in the PW dual homing protection list, so the switching performance is improved, and the problem that the occurrence of dual homing protection path switching triggers update of a large amount of MAC is solved.

Description

 Method and device for determining forwarding path in PW dual-homing protection scenario

 The present invention relates to the field of network communication technologies, and in particular, to a method and apparatus for determining a forwarding path in a PW (Pseudo Wire) dual-homing protection scenario. Background technique

 Internet-based services have emerged with new features: Real-time services are growing rapidly and business forms are diversified. In terms of reliability, it is necessary to reach the level of traditional telecommunication networks, such as the speed of protection switching <50ms.

 In the traditional VPLS (Virtual Private LAN Service) domain, only the valid PW forwarding path is saved in the MAC forwarding table on the PW side. The specific MAC table entries are shown in Table 1:

 Table 1

 The specific implementation manner of forwarding packets in the prior art is as follows:

 The packet coming in from the ingress receives the corresponding MAC entry based on the MAC address of the packet. The packet is forwarded according to the PW forwarding path in the MAC entry. If the PW dual-homing protection occurs, the MAC address entry corresponding to the MAC address of the PW path is updated, and the default PW forwarding path in the MAC entry is updated to the standby PW forwarding path.

In a specific application environment, a PW dual-homing protection may have multiple MAC data flows, and multiple MAC tables are saved on the device. As shown in Figure 1, two MAC flows enter the device from the primary PW path. , the device will learn 2 MACs, which correspond to the main PW exit, two MACs As shown in Table 2 and Table 3, respectively

 Table 2

 table 3

 After the PW switch occurs, two data streams enter the device from the standby PW path, and the device re-learns to two MACs, which correspond to the standby PW exit, as shown in Figure 4 and Table 5:

 According to the method in the prior art, if a protection path corresponds to a large number of MACs, when the protection path is switched between the dual-homed protection paths, after the traffic comes in from the new path, a large number of MAC updates are triggered, and the performance of the CPU is certain. Impact impact.

In addition, since the MAC is a single update, in the process of a large number of updates, the packets coming in from the entry of FIG. 1 cannot be switched to the path of the standby PW immediately by checking the MAC, resulting in poor handover performance. Summary of the invention

 The invention provides a method and a device for determining a forwarding path in a PW dual-homing protection scenario, which are used to solve the problem that a dual-homed protection path of a protection path occurs in the prior art, which will trigger a large number of

The MAC update has an impact on the performance of the CPU.

 In order to solve the above problems, the technical solution of the present invention is implemented as follows:

 A method for determining a forwarding path in a PW dual-homing protection scenario, the method includes: when a forwarding device receives a packet, obtaining a MAC address of the packet, and obtaining the obtained

The forwarding path index and the dual-homing protection flag corresponding to the MAC address; the same PW forwarding path corresponds to the same forwarding path index;

 Determining whether the PW dual-homed protection switching occurs on the egress PW according to the dual-homing protection flag, and if yes, determining the currently valid path by using the PW dual-homing protection table, and obtaining the valid from the PW dual-homing protection table according to the obtained forwarding path index. The index of the path;

 The PW forwarding path is obtained from the PW forwarding table by using the index of the obtained valid path. The method also includes:

 If it is determined that the PW dual-homed protection switching does not occur according to the dual-homing protection flag, the primary PW index is obtained, and the primary PW forwarding path is obtained from the PW forwarding table by using the primary PW index.

 The method also includes:

 When the forwarding device receives the packet from the primary PW path, if the PW dual-homed protection switching occurs, the dual-homing protection flag in the path index table is set to the dual-homed protection switching state, and the PW forwarding table includes the primary The primary PW forwarding table corresponding to the PW index and the standby PW forwarding table corresponding to the standby PW index;

The PW forwarding path is obtained from the PW forwarding table by using the obtained index of the valid path, including: The PW forwarding path is obtained from the corresponding primary PW forwarding table or the standby PW forwarding table according to the obtained primary PW index or the standby PW index.

 The process of obtaining the forwarding path index and the dual-homing protection flag corresponding to the obtained MAC address includes:

 Matching the obtained MAC address with the MAC address in the forwarding path index table to obtain the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address.

 An apparatus for determining a forwarding path in a PW dual-homing protection scenario, the apparatus includes: a forwarding scenario determining module, configured to: when receiving a packet, obtain a MAC address of the packet, and obtain the obtained MAC address corresponding to the MAC address Forwarding path index and dual-homing protection tag; the same PW forwarding path corresponds to the same forwarding path index;

 An effective path determining module, configured to determine, according to the dual-homing protection flag, whether a PW dual-homing protection switch occurs on the egress PW, and if yes, determine a currently valid path by using a PW dual-homing protection table, and according to the obtained forwarding path index The PW dual-homing protection table obtains an index of the valid path. The forwarding module is configured to obtain the PW forwarding path from the PW forwarding table by using the obtained index of the valid path.

 The effective path determination module is further configured to:

 If it is determined that the PW dual-homed protection switching does not occur according to the dual-homing protection flag, the primary PW index is obtained, and the primary PW forwarding path is obtained from the PW forwarding table by using the primary PW index.

 The device also includes:

a forwarding path index table maintenance module, configured to: when a packet entering from the primary PW path is received, if a PW dual-homing protection switch occurs, setting the dual-homing protection flag in the path index table to the PW forwarding table includes When the primary PW forwarding table corresponding to the primary PW index and the standby PW forwarding table corresponding to the standby PW index, the forwarding module uses the index of the obtained valid path from the PW When the PW forwarding path is obtained in the forwarding table, it is used to:

 The PW forwarding path is obtained from the corresponding primary PW forwarding table or the standby PW forwarding table according to the obtained primary PW index or the standby PW index.

 The forwarding scenario determining module is configured to: when obtaining the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address:

 Matching the obtained MAC address with the MAC address in the forwarding path index table to obtain the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address.

 The method and the device provided by the present invention, in the PW dual-homing protection scenario, the MAC table is separated from the PW, and the PW dual-protection table is further arranged between the MAC table and the PW forwarding entry. When the PW dual-homing protection switchover occurs, only the PW dual-homing protection table needs to be switched, and the original unicast traffic can be directly forwarded to the effective PW path. The entire process will not require a MAC update, effectively protecting CPU performance from this switch. DRAWINGS

 FIG. 1 is a PW dual-homing protection scenario under VPLS in the prior art;

 2 is a flowchart of a method for determining a forwarding path in a PW dual-homing protection scenario according to an embodiment of the present invention;

 FIG. 3 is a structural diagram of an apparatus for determining a forwarding path in a PW dual-homing protection scenario according to an embodiment of the present invention. detailed description

An embodiment of the present invention provides a method for determining a forwarding path in a PW dual-homing protection scenario, where the method includes: when a forwarding device receives a packet coming in from an ingress, obtains a source MAC address of the packet, and obtains the obtained MAC address. The address is matched with the MAC address in the forwarding path index table, and the forwarding path index and the dual-homing protection flag corresponding to the source MAC address are obtained, and the same PW forwarding path corresponds to the same forwarding path index; Export PW is Whether the PW dual-homed protection switchover occurs, if yes, the PW dual-homing protection table is used to determine the currently valid path, and the index of the valid path is obtained from the PW dual-homing protection table according to the obtained forwarding path index; The index gets the PW forwarding path from the PW forwarding table.

 As shown in FIG. 2, the embodiment of the present invention provides a method for determining a forwarding path in a PW dual-homing protection scenario, which specifically includes the following steps:

 Step 201: When the forwarding device receives the packet coming in from the ingress, obtain the MAC address of the packet, and match the obtained MAC address with the MAC address in the forwarding path index table (as shown in Table 6). Obtaining a forwarding path index and a dual-homing protection flag corresponding to the MAC address, where the same PW forwarding path corresponds to the same forwarding path index;

 In the embodiment of the present invention, one of the main contents of the forwarding path index table is a forwarding index (transmit index), and in a dual-homing protection or a normal scenario, the transmit index is always allocated in a resource pool, and the forwarding path is guaranteed not to be cover.

 Table 6

transmit index主 主 PW索引 PW index Step 202: Determine, according to the dual-homing protection flag, whether a PW dual-homing protection switch occurs on the egress PW, and if yes, determine a currently valid path by using a PW dual-homing protection table (as shown in Table 7), and according to the obtained forwarding The path index obtains the index of the valid path from the PW dual-homing protection table (as shown in Table 8), and proceeds to step 203; otherwise, proceeds to step 204.

Transmit index main main PW index PW index

 Transmit index preparation PW index PW index

 Table 7

 In the implementation of the present invention, the primary PW index and the standby PW index respectively correspond to one PW dual-homing protection table. When the PW dual-homing protection table is used to determine that the currently valid path is the primary PW forwarding path, the PW forwarding path is obtained through the PW dual-homing protection table corresponding to the primary PW path.

 Step 203: Obtain a PW forwarding path from the PW forwarding table (as shown in Table 8) by using the obtained index of the valid path.

 Table 8

 Step 204: If it is determined that the egress PW is normal according to the dual-homing protection flag, obtain a primary PW index; and obtain a primary PW forwarding path from the PW forwarding table by using a primary PW index.

 To ensure that the PW forwarding path is not updated when the packet is forwarded, the PW forwarding table obtains the PW forwarding path from the PW forwarding table by using the obtained index of the valid path, including:

 The PW forwarding path is obtained from the corresponding primary PW forwarding table or the standby PW forwarding table according to the obtained primary PW index or the standby PW index.

When the forwarding device receives the packet entering from the primary PW path, if the PW dual-homing protection switching occurs, the dual-homing protection flag in the path index table is set to the dual-homed protection switching state, and if the data The flow is switched to the slave PW path. The forwarding layer finds that the MAC already exists, and the MAC table results in the PW dual-homed protection flag. The transmit index is the corresponding PW. Dual-homed protection index, no need to initiate PW update.

 As shown in Figure 1, if the device is enabled with a PW dual-homing protection, the protection index PW FRR index1 corresponds to the primary PW1 and the standby PW2. The PW1 index is PW index1, and the PW2 index is PW index2. The specific implementation manner of selecting the forwarding path by using the method provided by the embodiment of the present invention may be:

 The device will create a PW dual-homing protection table (as shown in Table 9) and a PW forwarding table (as shown in Table 10). The PW forwarding table includes the forwarding table of the primary PW path and the standby PW path (as shown in Tables 10 and 11). ).

 Table 9

 In this embodiment, if it is determined that the current PW forwarding path is the primary PW path after the dual-homing protection is performed according to the PW dual-homing protection table, the table 10 is directly queried to obtain the PW export information.

 If the PW dual-homing protection table shows protect status =1, the current PW forwarding path is the standby PW path. Then, query the table 11 to obtain the PW export information.

In the scenario shown in FIG. 1, the data forwarding path is implemented by using the method provided by the embodiment of the present invention. The reverse forwarding process for path selection, including:

 If two MAC flows enter the device from the primary PW1 path, the device learns two MACs (as shown in Table 12 and Table 13), which correspond to the PW dual-homed protection path index, and the transmit index corresponds to PW FRR index 1. .

 When the data stream is switched to the slave PW path, the forwarding layer finds that the MAC already exists, and the MAC table results in the PW dual-homing protection flag, and the transmit index is the corresponding PW dual-homing protection index PW FRR index1, so there is no need to initiate the MAC table update. .

 As shown in FIG. 1 , a specific implementation manner of performing forward forwarding of a data flow by using the method provided by the embodiment of the present invention may be:

 Check the MAC match from the incoming message. If the MAC table indicates that the egress PW is dual-homed, the PW FRR index is obtained according to the MAC table. According to this, the PW dual-return protection table is checked. The active/standby status of the reference table is protected status=0. , select the main PW forwarding index PW index 1.

 Use the obtained PW forwarding index to check the PW forwarding table to obtain the PW export information.

 As shown in FIG. 3, according to the foregoing method, an embodiment of the present invention further provides an apparatus for determining a forwarding path in a PW dual-homing protection scenario, including:

 The forwarding scenario determining module 301 is configured to: when receiving the packet coming in from the portal, obtain the MAC address of the packet, and match the obtained MAC address with the MAC address in the forwarding path index table to obtain the obtained MAC address. The forwarding path index and the dual-homing protection flag corresponding to the MAC address, and the same PW forwarding path corresponds to the same forwarding path index;

The valid path determining module 302 is configured to determine, according to the dual-homing protection flag, whether the exit PW is The PW dual-homing protection switchover occurs. If yes, the PW dual-homing protection table is used to determine the currently valid path, and the index of the valid path is obtained from the PW dual-homing protection table according to the obtained forwarding path index.

 When the dual-homing protection scenario does not occur, the effective path determining module 302 provided by the device of the present invention is further configured to: if the PW dual-homed protection switching does not occur in the egress PW according to the dual-homing protection flag, obtain the primary PW index. The primary PW forwarding path is obtained from the PW forwarding table using the primary PW index.

 The forwarding module 303 is configured to obtain a PW forwarding path from the PW forwarding table by using an index of the obtained valid path.

 The forwarding module 303 is further configured to: when the PW forwarding table includes a primary PW forwarding table corresponding to the primary PW index and a standby PW forwarding table corresponding to the standby PW index, according to the obtained primary PW index or otherwise, the forwarding device learns The MAC address, the apparatus provided by the embodiment of the present invention further includes:

 The forwarding path index table maintenance module 304 is configured to: when receiving the packet entering from the primary PW path, if the PW dual-homing protection switching occurs, setting the dual-homing protection flag in the path index table to dual-homing protection switching Status, and save the PW dual-homed protection index corresponding to the packet MAC address.

 Because the MAC table is separated from the PW forwarding table, it is associated with the PW dual-homing protection. A large number of MACs only need to write the same PW dual-homed protection index as long as the egress is the same PW dual-homed protection path. When the PW dual-homing switchover occurs, you only need to modify the active/standby state in the PW dual-homing protection table to improve the switching performance.

The MAC address is separated from the PW forwarding table and is associated with the PW dual-homing protection. No matter whether the packet enters the forwarding device from the primary PW or the forwarding device from the standby PW, the packet is dual-homed. Updated to reduce the impact pressure on the CPU. The other embodiments of the invention are obtained according to the technical solution of the invention, which are also within the scope of the technical innovation of the invention.

 It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

Claim  A method for determining a forwarding path in a virtual link PW dual-homing protection scenario, the method comprising:  When receiving the packet, the forwarding device obtains the MAC address of the packet, and obtains the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address; the same PW forwarding path corresponds to the same forwarding path index;  Determining whether the PW dual-homed protection switching occurs on the egress PW according to the dual-homing protection flag, and if yes, determining the currently valid path by using the PW dual-homing protection table, and obtaining the valid from the PW dual-homing protection table according to the obtained forwarding path index. The index of the path;  The PW forwarding path is obtained from the PW forwarding table by using the index of the obtained valid path. 2. The method of claim 1, wherein the method further comprises:  If it is determined that the PW dual-homed protection switching does not occur according to the dual-homing protection flag, the primary PW index is obtained, and the primary PW forwarding path is obtained from the PW forwarding table by using the primary PW index.  3. The method according to claim 1, wherein the method further comprises:  When the forwarding device receives the packet from the primary PW path, if the PW dual-homed protection switch occurs, the dual-homing protection flag in the path index table is set to the dual-homed protection switching state. The method according to any one of claims 1 to 3, wherein the PW forwarding includes a primary PW forwarding table corresponding to the primary PW index and a standby PW forwarding table corresponding to the standby PW index;  The PW forwarding path is obtained from the PW forwarding table by using the index of the obtained valid path, including: The PW forwarding path is obtained from the corresponding primary PW forwarding table or the standby PW forwarding table according to the obtained primary PW index or the standby PW index. The method according to any one of claims 1 to 3, wherein the obtaining the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address comprises:  Matching the obtained MAC address with the MAC address in the forwarding path index table to obtain the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address.  6. A device for determining a forwarding path in a PW dual-homing protection scenario, the device comprising:  The forwarding scenario determining module is configured to: when receiving the packet, obtain the MAC address of the packet, and obtain the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address; the same PW forwarding path corresponds to the same forwarding Path index  An effective path determining module, configured to determine, according to the dual-homing protection flag, whether a PW dual-homing protection switch occurs on the egress PW, and if yes, determine a currently valid path by using a PW dual-homing protection table, and according to the obtained forwarding path index The PW dual-homing protection table obtains an index of the valid path. The forwarding module is configured to obtain the PW forwarding path from the PW forwarding table by using the obtained index of the valid path.  The device according to claim 6, wherein the effective path determining module is further configured to:  If it is determined that the PW dual-homed protection switching does not occur according to the dual-homing protection flag, the primary PW index is obtained, and the primary PW forwarding path is obtained from the PW forwarding table by using the primary PW index.  8. The device of claim 6, wherein the device further comprises:  The forwarding path index table maintenance module is configured to: when receiving the packet entering from the primary PW path, if the PW dual-homed protection switching occurs, setting the dual-homing protection flag in the path index table The device according to any one of claims 6 to 8, wherein the PW forwarding table includes a primary PW forwarding table corresponding to the primary PW index and a standby PW forwarding table corresponding to the standby PW index. When the forwarding module obtains the PW forwarding path from the PW forwarding table by using the obtained index of the valid path, the forwarding module is configured to:  The PW forwarding path is obtained from the corresponding primary PW forwarding table or the standby PW forwarding table according to the obtained primary PW index or the standby PW index.  The device according to any one of claims 6 to 8, wherein the forwarding scenario determining module is configured to: when obtaining the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address:  Matching the obtained MAC address with the MAC address in the forwarding path index table to obtain the obtained forwarding path index and the dual-homing protection flag corresponding to the MAC address.