WO2012159489A1

WO2012159489A1 - Switching method, system and dual homing provider device for pseudowire dual homing network

Info

Publication number: WO2012159489A1
Application number: PCT/CN2012/072915
Authority: WO
Inventors: 杨学成; 张利锋; 厉霞明; 叶勇
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-05-25
Filing date: 2012-03-23
Publication date: 2012-11-29
Also published as: CN102325037A; CN102325037B

Abstract

Provided in the present invention is a switching method, a system and a dual homing provider device for a pseudowire dual homing network, the switching method comprising: when a fault occurs on a primary link and a user terminal switches traffic to a standby link, a primary dual homing provider device of the primary link initiates an intermediate switching pseudowire, said intermediate switching pseudowire being the pseudowire established between the primary dual homing provider device and a standby dual homing provider device of the standby link; the primary dual homing provider device switches traffic to the intermediate switching pseudowire for transmission. By means of adding an intermediate switching pseudowire, the present invention improves network switching performance, improves switchback performance, ensures network stability, and provides improved service for the client.

Description

Method, system and dual-homing operator equipment for switching pseudowire dual-homing network

The present invention relates to the field of data network communication technologies, and in particular, to a Pseudo Wire (PW) dual-homing network switching method, system, and dual-homing carrier equipment. Background technique

In order to meet the trend of metropolitan area network service transformation and triple play, network operators tend to adopt high-efficiency and low-cost packet transmission networks to implement multi-service bearers, provide flexible network services, improve network resource utilization, and reduce network deployment complexity. Degrees, enhance the flexibility of network services, bring more economic benefits.

Layer 2 Virtual Private Network (L2VPN) is a technology that relies on Internet service providers and network service providers to establish private data communication networks in public networks. It can be divided into two types: Virtual Private Lan Service (VPLS) and Virtual Leased Line (VLL). The former is based on Ethernet forwarding and supports point-to-multipoint network deployment. The latter is virtual. Dedicated line service, based on Ethernet, Asynchronous Transfer Mode (ATM), Time-Division Multiplexing (TDM), High-Levd Data Link Control (HDLC), Frame Relay ( Layer 2 service emulation, such as Frame Relay (FR) and Point to Point Protocol (PPP), only supports point-to-point network deployment.

Due to the high reliability requirements of carrier Ethernet, operators pay great attention to the service convergence speed when the network fails. This requires more attention to fault response and protection switching capability during network deployment. PW operation management proposed by the IETF organization PWE3 working group Operation Administration & Maintenance (OAM) Message Mapping and PW redundancy technologies are considered for this purpose. PW OAM Message Mapping ( draft-ietf-pwe3-oam-msg-map-12 ) is a pseudowire fault notification technology. In the point-to-point emulation service, the fault mapping between the AC (access circuit) and the PW (pseudowire) is supported. When the AC is faulty, the association with the PW layer OAM is implemented, and the fault is advertised to the remote end through the PWE3 protocol packet. The remote end can quickly learn that the service path has failed and perform corresponding subsequent processing.

PW redundancy (draft-ietf-pwe3-redundancy-01) is a pseudowire redundancy protection technique. In order to meet the high reliability requirements of carrier Ethernet, network backup is considered to implement the path backup mechanism. When the working path fails, user traffic is quickly switched to the backup path to minimize traffic loss. The working path and backup path relationship can be generated through protocol signaling negotiation or by user-specified designation. The PW OAM message mapping technology and the PW redundancy technology are interrelated. The former is mainly responsible for fault notification. The latter is mainly responsible for responding to the fault information that is advertised, determining the current effective path, and guiding traffic forwarding. The two complement each other and jointly complete the fast convergence of the fault. .

A dual-homing protection switching method is used to perform Bidirectional Forwarding Detection (BFD) on the PW link and Ethernet OAM on the AC link. When the Ethernet OAM detects a fault, the fault is caused by the OAM through the oam mapping method. Passed to BFD to achieve end-to-end fault delivery and linkage. Thereby, the impact of network failure on the service is reduced, the probability of service unavailability is reduced, and the reliability of the service is improved.

An existing method for fast failback of inter-network links in a transport-oriented multi-protocol label switching (TMPLS) network and a Synchronous Digital Hierarchy (SDH) network hybrid network (PW) When the SDH network is switched back to the primary path, the SDH network immediately informs the TMPLS network remote provider Edge (PE) to perform PW switchback and eliminate the two-side switchover recovery (Wait To Restore, WTR) inconsistency. The reliability and flexibility of the network are improved, and the carrier-class protection switching of the bearer service is effectively guaranteed. In summary, the existing PW dual-homing network deployment is as shown in Figure 1. PE1 deploys PW1 and PW2 to form PW dual-homing protection. User Edge (CE) deploys AC1 and AC2 to form a multi-chassis. The Multi-Chassis-Link Aggregation Group (MC-LAG) protects, and PE2 and PE3 form a primary backup path, where " ---► , represents the network traffic path before AC1 failure, and " ► " represents AC 1 failure. Post network process path. The following problems exist in network switching:

During normal operation, traffic is forwarded in both directions along the primary path (PE1-PE2-CE). Once the AC1 link in the primary path fails, both CE and PE2 can immediately sense the traffic. On the one hand, the CE reselects AC2 for traffic forwarding. Side traffic switching performance T _CE switching performance = T _CE fault detection + T _CE switching behavior; on the other hand, PE2 needs to transmit "AC1 fault" information to PE1 through oam mapping technology, PE1 to reselect PW2 for traffic forwarding, PE1 side Flow switching performance T _P m » can = T _PE2 fault detection + TPE2 fault transmission + TPEI switching behavior. Since the traffic depends on the path selection on both sides, the amount of switching of the entire network is MAX (TCE switching performance, TPEI switching performance); considering T fault detection and T switching behavior is; ^ two steps necessary for quantity switching, technology The same is true, but the _TPE2 fault transmission is uncontrollable. The existing fault transmission mostly adopts label distribution protocol (LDP) signaling, BFD or TP-OAM, etc. First, LDP, BFD, TP-OAM is a series of extensions that increase the complexity of PE2 equipment. In addition, fault-transmission packets need to span the PE2-PE1 network. When the network is large, the transmission delay becomes larger and the possibility of packet loss increases. This may cause the T _PE2 failover to become the switching performance bottleneck of the entire network.

It can be seen that in the switching technology of the existing PW dual-homing network, the fault transmission of T _PE2 is uncontrollable, and the network switching performance cannot be guaranteed.

Summary of the invention

The embodiment of the invention provides a method for switching a pseudo-line dual-homing network, a system, and a dual-homing operator device, which can implement controllable and guaranteed network switching performance of _TPE2 fault transmission in the switching technology of the PW dual-homing network. An embodiment of the present invention provides a method for switching a pseudo-line dual-homed network, including: when a primary link fails, and a user equipment switches traffic to a standby link, the primary dual-homing carrier device in the primary link enables the middle. Inverting a pseudowire, the intermediate switching pseudowire is a pseudowire established between the primary dual-homing carrier device and a standby dual-homing carrier device in the standby link; the primary dual-homing carrier device switches traffic to The intermediate switching pseudowire is transmitted. The switching method further includes:

When the primary link fails to recover and the user equipment delays the traffic back to the primary link, the primary dual-homed carrier device switches back the traffic to the primary link for transmission.

The method further includes: the primary dual-homing operation, before the primary dual-homing carrier device in the primary link is configured to enable the intermediate switching pseudowire, when the primary link fails, and the user equipment switches the traffic to the standby link. Establishing a physical connection and the intermediate switching pseudowire between the merchant device and the standby dual-homed carrier device;

The primary dual-homed carrier device forms a protection relationship between the primary link and the intermediate switching pseudowire, and associates the primary pseudowire with the intermediate switching pseudowire. When the primary link fails, the user equipment When the traffic is switched to the standby link, the intermediate switching pseudowire is enabled; when the primary link fails to recover, and the user equipment delays the traffic back to the primary link, The intermediate switching pseudowire is not enabled.

The method also includes: and a status of the alternate link.

An embodiment of the present invention provides a dual-homing carrier device, including:

An enabling unit, configured to enable an intermediate switching pseudowire when the primary link fails and the user equipment switches the traffic to the standby link, where the intermediate switching pseudowire is in the primary dual-homing carrier device and the standby link a pseudowire established between the alternate dual-homed carrier devices;

And a switching unit, configured to switch the traffic to the intermediate switching pseudowire for transmission. The dual-homed carrier device further includes:

And a failback unit, configured to: when the primary link fails to recover, and the user equipment delays the traffic back to the primary link, the traffic is switched back to the primary link for transmission.

The dual-homed carrier device further includes:

a connection establishing unit, configured to establish a physical connection and the intermediate switching pseudowire with the standby dual-homing carrier device;

a setting unit, configured to form a protection relationship between the primary link and the intermediate switching pseudowire, and associate a primary pseudowire with the intermediate switching pseudowire, and when the primary link fails, the user equipment switches the traffic When the backup link is to the standby link, the intermediate switching pseudowire is enabled; when the primary link fails to recover, and the user equipment delays the traffic back to the primary link, the intermediate switching is reversed. The line is not enabled.

The dual-homed carrier device further includes: a state of using the link.

An embodiment of the present invention provides a switching system for a pseudowire dual-homing network, including:

The user equipment is configured to switch the traffic to the standby link when the primary link fails, and the primary dual-homing carrier device in the primary link, when the user equipment switches the traffic to the standby link. The traffic is switched to the intermediate switching pseudowire for transmission, and the intermediate switching pseudowire is a pseudowire established between the primary dual-homing operator equipment and the standby dual-homing carrier equipment in the standby link.

The user equipment is further configured to delay the traffic back to the primary link when the primary link fails to recover;

The primary dual-homing carrier device in the primary link is further configured to: when the user equipment delays the traffic back to the primary link, the traffic is switched back to the primary link for transmission.

The switching method of the pseudowire dual-homing network provided by the embodiment of the present invention adopts a new intermediate switching pseudo The line improves the network switching performance, improves the switching performance, ensures the stability of the network, and provides customers with better services. DRAWINGS

FIG. 1 is a schematic diagram of a scenario of a conventional PW dual-homing network;

2 is a flowchart of a method for switching a pseudowire dual-homing network according to an embodiment of the present invention;

3 is a module interaction diagram of PE2 according to an embodiment of the present invention;

4 is a scenario top view of a PW dual-homing network according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a dual-homed carrier device according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another dual-homing carrier device according to an embodiment of the present invention. detailed description

The technical problems, the technical solutions, and the advantages of the embodiments of the present invention will be more clearly described in the following description.

As shown in FIG. 2, an embodiment of the present invention provides a method for switching a pseudowire dual-homing network, including:

5101. When the primary link (AC1) fails and the user equipment (CE) switches traffic to the standby link (AC2), the primary dual-homed carrier device (PE2) in the primary link (AC1) enables intermediate switching pseudo Line (I-PW), the I-PW is a pseudowire established between PE2 and the alternate dual-homed carrier equipment (PE3) in AC2;

5102. PE2 switches the traffic to the I-PW for transmission.

After the step S102 is completed, the traffic is forwarded on the path formed by the primary pseudowire (PW1) + I-PW+AC2, and the traffic is switched when the primary link fails.

Switching performance analysis: The AC1 link is faulty, and both CE and PE2 can be immediately aware. On the one hand, the CE will re-select AC2 for traffic forwarding, and the CE side traffic switching performance T _CE switching performance = T _CE fault detection + TCE switching behavior; In terms, PE2 does not need to pass "AC1 fault" information through oam mapping. The technology is passed to PE1, only PE2 needs to transfer traffic to I-PW, and PE2 side traffic switching performance

TPE2 switching performance = TPE2 fault detection + TPE2 switching behavior. Since traffic depends on path selection on both sides, the traffic switching performance of the entire network is MAX (TCE handover performance, T _PE2 handover performance), which reduces the uncertainty of T _PE2 failure transmission and improves network handover performance.

Before the step S101 is performed, the foregoing switching method may further include the following steps:

Establish a physical connection and I-PW between PE2 and PE3.

PE2 establishes a protection relationship between the AC1 and the I-PW, and associates the PW1 with the I-PW. When the AC1 fails and the CE switches the traffic to AC2, the I-PW is enabled. When the AC1 fails, the CE delays the traffic. When switching to AC1, the I-PW is disabled.

The status of AC1 and AC2 is obtained through negotiation between PE2 and CE.

In addition, the following problems exist in the prior art: When the AC1 link fails, the traffic is switched to the alternate path (PE1-PE3-CE) for bidirectional forwarding. When the AC1 link recovers, the traffic needs to be switched back to The primary path (PE1-PE2-CE) is forwarded because the primary path is a more desirable forwarding path for the operator when the network is deployed, and may have advantages in terms of QoS. The existing switchback technology mostly adopts the WTR delay switchback mode (that is, the AC1 does not immediately switch back when it recovers, but waits for a period of time to switch back again, mainly to prevent the AC1 state oscillation from affecting the traffic switching oscillation). In the network, both PE1 and CE adopt this mode. When the AC1 link is restored, both CE and PE2 can be aware. On the one hand, the CE performs the WTR delay and waits for the switchback. In addition, PE2 needs to transfer the "AC1 recovery" to PE1, PE1. The WTR delay is also waited for the switchback. CE and PE1 each perform WTR delay processing (WTR values are separately configurable, delay timers are maintained separately), and there is no interaction mechanism between them. Eventually, the timing of the two switches is inconsistent, and the time difference is the switchback. Performance, can produce a lot of unbearable packet loss.

In order to solve the above problems in the prior art, the foregoing switching method may further include the following steps: When the AC1 fails to recover and the CE delays the traffic back to AC1, PE1 switches back the traffic to AC1 for transmission. Switchback performance analysis: When the AC1 link is faulty, both CE and PE2 can detect the traffic immediately. However, PE2 and CE do not process the traffic switchback at this time. There is no packet loss at this time. When the WTR of the CE is delayed, the CE will Reselect AC1 forwarding traffic, and its switching performance T _CE switching performance = TCE switching behavior (when the WTR delay directly triggers the switching behavior, so no TCE fault detection is required); on the other hand, PE2 knows that CE is switched back to AC1. PE2 will cut back the traffic to AC1, and its back-cut performance T _PE2 back-cut performance = TMC-LAG + T _PE2 . Since the traffic depends on the path selection on both sides, the traffic switching performance of the entire network is MAX (T _CE switching performance, T _PE2 switching performance), and the switchback mode of the present invention only depends on the WTR delay processing of the CE device to control the entire The back-cut timing of the network improves the back-cut performance and avoids the inconsistency of the switchback timing.

In summary, the switching method of the pseudowire dual-homing network provided by the embodiment of the present invention improves the network switching performance, improves the back-cut performance, ensures the stability of the network, and provides a more perfect solution for the customer by adding an intermediate switching pseudowire. service. And the method is completely based on the existing hardware implementation of the device, and only needs to provide technical support at the software control level, which is easy to implement.

The following describes a handover method provided by an embodiment of the present invention.

As shown in FIG. 3, the PE2 is provided with: a service management module, an I-PW protection group module, and an MC-LAG module;

The service management module is mainly responsible for the association between the AC information and the PW information; at the level of the control plane, serving the forwarding plane; further comprising: a PW forwarding table module and an AC forwarding table module;

PW forwarding table module: The receiving processing logic of the PW side data packet is mainly implemented, that is, the PE device receives the data packet from the PW side, performs routing according to the PW forwarding table, and forwards the packet; the level belongs to the forwarding plane;

AC forwarding table module: It mainly implements the receiving processing logic of the AC side data packet, that is, the PE device receives the data packet from the AC side, performs routing according to the AC forwarding table, and forwards it; the level belongs to the forwarding plane.

I-PW protection group module: Maintains the protection relationship between the AC and the I-PW. The AC defaults to the primary path. I-PW defaults to the alternate path; the preferred path is determined according to the state of the AC and I-PW; the control plane is hierarchically;

MC-LAG module: Mainly maintains the active/standby state of the AC. The AC state on the PE is controlled by the MC-LAG module of the CE device and is notified by protocol packets.

With reference to FIG. 4, this embodiment implements fast switching of the PW dual-homing network, where "--►" represents the AC1 pre-failure network traffic path, and "►" represents the AC1 post-fault network flow path. This embodiment includes the following steps. :

Step A: Perform the deployment of the common PW dual-homing network. For the specific topology, refer to Figure 1. Step A specifically includes:

A Virtual Leased Line (VLL) service is established between Al, PE1, and PE2 to form PW1.

A2, a VLL service is established between PE1 and PE3, and PW2 is formed.

A3 and PE1 form a PW dual-protection group relationship between PW1 and PW2, PW1 is the primary and PW2 is the standby.

A4, PE2, PE3, and CE are deployed in the MC-LAG dual-homed network. The AC1 and AC2 are in the protection group relationship. AC1 is the primary and AC2 is the standby.

After step A is completed, the normal PW dual-homing network deployment is completed.

The "Service Management Module" on PE2 maintains the "AC Forwarding Table Module" and "PW Forwarding Table Module" according to the VLL service configuration. The "AC forwarding table module" forms an AC forwarding table (see Table 1), and the "PW forwarding table module" forms a PW forwarding table (see Table 2). Normally, the traffic of PE1-CE is based on Table 1 and Table 2. Select "PE1-PE2-CE" as the forwarding path and the traffic can communicate with each other.

Table 1: PE forwarding table AC forwarding table Entrance Exit

PW1 AC1

Table 2: PE2 Device PW Forwarding Table

Step B: On the basis of the common PW dual-homing network, the I-PW function is added.

Step B specifically includes:

Bl, PE2 and PE3 need to establish a physical connection;

B2, PE2 and PE3 are connected to each other to establish an outer tunnel;

On B3, PE2, and PE3, a new PW is created on the VLL service, which is called I-PW, and is bundled with the AC as an I-PW protection group.

After step B is completed, the deployment of the new PW dual-homing network is completed.

Among them, "I-PW protection group module" forms a protection relationship between AC1 and I-PW. By default, AC1 is active and I-PW is standby; "AC forwarding table module" and "PW forwarding table module" are protected by "I-PW". The group module "is affected, there is an update of forwarding information, see Table 3, Table 4. According to the active entries in Table 3 and Table 4, PE1 and PE2-CE are used as the forwarding path. The traffic can communicate with each other.

Table 3: PE2 Device AC Forwarding Table

Table 4: PE2 Device PW Forwarding Table

If the AC1 link fails, the MC-LAG module immediately exchanges protocol packets with the CE. The MC-LAG protocol negotiates that AC1 is standby and AC2 is active. The MC-LAG module notifies I- The PW protection group module updates the active/standby status to AC1 as standby and I-PW as Active;

Step D: The "I-PW protection group module" notifies the updated service status to the "service management module", and the "service management module" refreshes the forwarding table, and finally the "AC forwarding table module" and the "PW forwarding table" The information of the module is updated. See Table 5 and Table 6. The traffic of PE1-CE is based on the active entry in Table 6. "PE1-PE2-PE3-CE" is the forwarding path, and the traffic can communicate with each other.

Table 5: PE2 Device AC Forwarding Table

Table 6: PE2 Device PW Forwarding Table

At this point, after the AC1 link fails, the traffic switching is completed.

Switching performance analysis: The AC1 link is faulty, and both CE and PE2 can be immediately aware. On the one hand, the CE will re-select AC2 for traffic forwarding, and the CE side traffic switching performance T _CE switching performance = T _CE fault detection + TCE switching behavior; On the other hand, the PE2 does not need to pass the "AC1 fault" information to PE1 through the oam mapping technology. Only PE2 needs to transfer traffic to the I-PW path. PE2 side traffic switching performance TPE2 switching performance = TPE2 fault detection + TPE2 switching behavior . Since the traffic depends on the path selection on both sides, the traffic switching performance of the entire network is MAX (TCE performance, TPE2 performance), which reduces the uncontrollable factors of T _PE2 fault transmission. Its performance is much better than that of ordinary PW dual-homing network switching technology. Great improvement.

In the case of the fault recovery of the AC1 link, the CE uses the WTR delay switchback policy. The MC-LAG module interacts with the CE. The MC-LAG protocol still negotiates that AC1 is standby and AC2 is active. The status of the forwarding table has not changed. The status of the corresponding forwarding table remains unchanged. The traffic is still selected as the forwarding path. The traffic can communicate with each other.

Step F: After the WTR of the CE device times out, the MC-LAG protocol renegotiates AC1 as Active, AC2 is standby; notify the "MC-LAG module" of PE2 by protocol packet; Step G, "MC-LAG module" responds to the negotiation result, and informs the "I-PW protection group module" to update the active/standby status to AC1 is active and I-PW is standby;

Step H: The "I-PW protection group module" notifies the updated service status to the "service management module", and the "service management module" refreshes the forwarding table, and finally the "AC forwarding table module" and the "PW forwarding table" The information of the module is updated. See Table 7 and Table 8. The traffic of PE1-CE is based on the active entry in Table 8. "PE1-PE2 -CE" is the forwarding path, and the traffic can communicate with each other.

Table 7: PE2 Device AC Forwarding Table

Table 8: PE2 Device PW Forwarding Table

At this point, after the AC 1 link fails and the WTR delays, the traffic switchback is completed.

Switchback performance analysis: When the AC1 link is faulty, both CE and PE2 can be detected immediately. However, the AC1 state of the MC-LAG is still standby. PE2 and CE do not process traffic switchback. when the WTR delay CE, MC-LAG protocol AC1 state reset to active, - CE aspects will reselect forward traffic AC1, which back cut performance properties T = TcE _CE switchback switchback behavior directly (after delay WTR Triggering the switchback behavior, so no _TCE fault detection is required. On the other hand, after the "MC-LAG module" of PE2 responds to the negotiation result, the forwarding table is refreshed again, and the AC1 path forwarding traffic is reselected, and its switching performance is 回2. = TMC-LAG + TPE2 switchback behavior. Since the traffic depends on the path selection on both sides, the traffic switching performance of the entire network is MAX (T _CE switchback performance, T _PE2 switchback performance), which avoids the problem of inconsistency of the switchback timing caused by WTR processing at both ends. Relying on the WTR delay processing of the CE device to control the switchback timing of the entire network, improving the switchback performance. As shown in FIG. 5, an embodiment of the present invention further provides a dual-homing carrier device, including: an enabling unit, configured to enable intermediate switching pseudo when a primary link fails and a user equipment switches traffic to a standby link. The line, the intermediate switching pseudowire is a pseudowire established between the dual-homing operator equipment and the standby dual-homing carrier equipment in the standby link;

The switching unit is configured to switch the traffic to the intermediate switching pseudowire for transmission.

As shown in FIG. 6, the dual-homed carrier device may further include:

The switchback unit is configured to perform traffic back to the primary link for transmission when the primary link fails to recover and the user equipment delays the traffic back to the primary link.

As shown in FIG. 6, the dual-homed carrier device may further include:

a connection establishing unit, configured to establish a physical connection and an intermediate switching pseudowire with the standby dual-homed carrier device;

The setting unit is configured to form a protection relationship between the primary link and the intermediate switching pseudowire, and associate the primary pseudowire with the intermediate switching pseudowire. When the primary link fails and the user equipment switches the traffic to the standby link, the intermediate switching is performed. The pseudowire is enabled. When the primary link recovers and the user equipment delays the traffic back to the primary link, the intermediate switching pseudowire is disabled.

As shown in FIG. 6, the dual-homed carrier device may further include:

The state obtaining unit is configured to obtain a state of the primary link and the standby link by negotiating with the client device.

The dual-homed carrier device provided by the embodiment of the invention not only improves the network switching performance, but also further improves the back-cut performance, ensures the stability of the network, and provides a more perfect service to the client.

In addition, the embodiment of the present invention further provides a switching system for a pseudowire dual-homing network, including: a client device, configured to switch traffic to a standby link when the primary link fails; The home carrier device is configured to switch the traffic to the intermediate switching pseudowire for transmission when the user equipment switches the traffic to the standby link, and the intermediate switching pseudowire is the standby dual in the dual-homed carrier device and the standby link. A pseudowire established between the home carrier devices. The user equipment can also be used to delay the traffic back to the primary link when the primary link fails.

The primary dual-homed carrier device in the primary link can also be used to switch traffic back to the primary link for transmission when the user equipment delays the traffic back to the primary link.

The switching system of the pseudowire dual-homing network provided by the embodiment of the invention not only improves the network switching performance, but also further improves the switching performance, ensures the stability of the network, and provides a better service to the customer.

It will be understood by those skilled in the art that all or part of the steps of the method for realizing the above facts may be completed by a program instructing related hardware, and the above program may be stored in a storage medium readable by a computer, the program When executed, the above steps are included. The above storage medium may be a ROM/RAM, a magnetic disk, an optical disk or the like.

The above is a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It should be considered as the scope of protection of the present invention.

Claims

Claim

A method for switching a pseudo-line dual-homing network, the method comprising: when a primary link fails, and the user equipment switches the traffic to the standby link, the primary dual-homing operator in the primary link The device enables the intermediate switching pseudowire, where the intermediate switching pseudowire is a pseudowire established between the primary dual-homed carrier device and the standby dual-homing carrier device in the standby link; the primary dual-homing carrier device The flow is switched to the intermediate switching pseudowire for transmission.

2. The handover method according to claim 1, wherein the method further comprises: when the primary link fails to recover, and the user equipment delays the traffic back to the primary link, The primary dual-homed carrier device retries traffic to the primary link for transmission.

The handover method according to claim 1, wherein when the primary link fails and the user equipment switches the traffic to the standby link, the primary dual-homing carrier device in the primary link enables the middle. Before the pseudowire is reversed, the method further includes:

Establishing a physical connection and the intermediate switching pseudowire between the primary dual-homed carrier device and the standby dual-homing carrier device;

4. The handover method according to claim 1, wherein the method further comprises: and a state of the standby link.

A dual-homed carrier device, the dual-homing carrier device includes: an enabling unit, configured to enable intermediate switching pseudo when the primary link fails and the user equipment switches traffic to the standby link a line, the intermediate switching pseudowire is the primary dual-homing carrier device a pseudowire established between the alternate dual-homed carrier device in the alternate link;

And a switching unit, configured to switch the traffic to the intermediate switching pseudowire for transmission.

6. The dual-homed carrier device of claim 5, wherein the dual-homing carrier device further comprises:

The dual-homed carrier device of claim 5, wherein the dual-homing carrier device further comprises:

8. The dual-homed carrier device of claim 5, wherein the dual-homed carrier device further comprises: a state of the link.

A switching system for a pseudo-line dual-homing network, the switching system comprising: a user equipment, configured to switch traffic to a standby link when the primary link fails; The dual-homed carrier device is configured to switch the traffic to the intermediate switching pseudowire for transmitting, when the user equipment switches the traffic to the standby link, where the intermediate switching pseudowire is the primary dual-homing carrier device and A pseudowire established between the alternate dual-homed carrier devices in the standby link.

10. The switching system of claim 9 wherein: