CN106470159B

CN106470159B - Tunnel convergence method and device

Info

Publication number: CN106470159B
Application number: CN201510508821.0A
Authority: CN
Inventors: 曾维
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2015-08-18
Filing date: 2015-08-18
Publication date: 2020-09-15
Anticipated expiration: 2035-08-18
Also published as: CN106470159A; WO2017028596A1

Abstract

The invention provides a method and a device for tunnel convergence, wherein the method comprises the following steps: the leaf node of the label forwarding path tunnel sends a label mapping message which does not carry an MBB mark to an upstream node which updates the inactive state on a first link at present, the label mapping message is used for indicating that the upstream node is in an MBB notification message waiting state, the leaf node sets an upstream control block in the inactive state as an upstream control block in the active state, and the leaf node issues forwarding information through the first link, so that the problem of slow convergence of an mLDP tunnel in an MBB scene is solved, and the rapid convergence of the mLDP tunnel is realized.

Description

Tunnel convergence method and device

Technical Field

The present invention relates to the field of communications, and in particular, to a method and an apparatus for tunnel convergence.

Background

A multicast Virtual Private Network (VPN) is a technology that supports multicast services based on the existing Border Gateway Protocol (BGP)/multi-Protocol label switching (MPLS) IP VPN, and the technology encapsulates multicast packets in a Private Network and transmits the multicast packets through multicast tunnels established between Network segments to complete the transmission of multicast data between Private networks.

The multicast VPN technology mainly solves the problems that how to perform Reverse Path Forwarding (RPF for short) check to achieve the purpose of Forwarding multicast data under the condition that a public network does not know private network routing, private network multicast sources and destination addresses are overlapped, how to forward a private network multicast data stream to a required private network, and the like. In the related art, the implementation modes include a Multicast Domain (MD) and an MVPN P2MP (point-to-multipoint); fig. 1 is a schematic diagram of a typical MVPN networking in the related art, and as shown in fig. 1, a public network of MVPN P2MP does not need to maintain a Multicast state, PE and P devices only need to establish a basic tunnel, and a multi-protocol Label distribution protocol (mLDP) is a technology for establishing the basic tunnel.

Fig. 2 is a schematic diagram of a typical mLDP networking in the related art, and as shown in fig. 2, a Label Switched Path (LSP) of the mLDP is composed of a root node, a plurality of intermediate nodes, and a plurality of leaf nodes. The general steps for establishing an ordinary mLDP LSP are as follows:

1. the MVPN informs the addition of leaf nodes and root nodes;

2. initiating the establishment and the removal of an mLDP LSP by a leaf node; after the leaf nodes are added, the optimal route of the root node can be found, and a label mapping message is determined to be announced to which intermediate node;

3. after receiving the notice of the leaf node, the intermediate node records the information such as the label value of the notice of the leaf node, then searches the route and notices the label mapping message to the upstream as the leaf node, and simultaneously issues and forwards the message to form a label forwarding table;

4. and until the root node is reached, the root node records the received label information, transmits and forwards the label information, and completes the establishment of the whole LSP.

Firstly, establishing and then dismantling (Make Before Break, abbreviated as MBB) processing is an optional extension of the mLDP LSP establishing process; when a link is up or a route is changed, the optimal route reaching a root node may be changed, and an LSP may be broken to cause short packet loss until the LSP is converged to a new upstream node again; the purpose of MBB is to guarantee that the time to packet loss is as short as possible when this happens,

fig. 3 is a schematic diagram of a typical MBB scenario networking in the related art, and as shown in fig. 3, assuming that all nodes are MBB-enabled, LSR1(Label Switched Router, which generally refers to a device supporting Label switching, such as a Router, a switch, etc.) is a tunnel root node, LSR4 is a tunnel leaf node, and LSR2 and LSR3 are tunnel intermediate nodes, and a detailed process of MBB occurrence is as follows:

an mLDP tunnel is established between the LSRs 4-1;

at this time, the route on the LSR4 changes, the next hop of the optimal route to the root node LSR1 is LSR3, LSR4 will apply for a new label, send a label mapping message carrying An MBB label to LSR3, and generate An inactive upstream control block (inactive access element resources of An upstream neighbor advertisement label, hereinafter referred to as inactive), and at this time, the traffic forwarding still goes through the LSR 4-1 tunnels;

the LSR3 receives the label mapping message with the MBB label sent by the LSR4 and also sends a label mapping message with the MBB label to the LSR2 in the same way until the root node LSR 1;

the LSR1 is the root node of the tunnel and will return an MBB notification message to LSR2 that it is ready to establish the tunnel; MBB notification messages are passed on in sequence;

when receiving the MBB notification message sent by the LSR3, the LSR4 sets the inactive upstream control block to An activated state (active element, hereinafter referred to as active) and sends forwarding information, and simultaneously sends a label cancellation message to the initial optimal upstream LSR1 and deletes old forwarding information, and the tunnel is switched from the LSR4-LSR1 to the LSR4-LSR3-LSR2-LSR 1; when the flow still goes to the old tunnel before the new tunnel is established, and the old tunnel is cut off after the new tunnel is established, the phenomenon of packet loss can not occur; the purpose of MBB is achieved;

if the LSR1 does not enable MBB, no MBB notification message is sent to the LSR2, the LSR2 does not return the MBB notification message to the LSR3, and the LSR3 does not return the MBB notification message to the LSR 4; the LSR4 has not received the MBB notification message returned from the upstream, the LSR4 waits until the MBB is overtime, and the LSR4 processes the MBB notification message as if the MBB notification message is received after the MBB is overtime;

the problem now is that if the MBB waiting time at the leaf node LSR4 is configured to be long, and the root node LSR1 is not configured with MBBs or packet congestion causes that the LSR4 has not received MBB notification message, when LSR4 is waiting for MBB notification message, if the MBB is enabled at LSR4, LSR4 still waits for MBB timeout to switch the tunnel to a new path without immediately switching.

For the intermediate node LSR3, if the waiting time of configured MBB is long, when the leaf node LSR4 enables MBB, LSR3 will wait for MBB notification message until overtime can not forward, and can not return MBB notification message to LSR4, and tunnel can not be established; this may result in slow tunnel convergence, may result in loops, and may even result in black holes in traffic.

Aiming at the problem of slow convergence of an mLDP tunnel in an MBB scene in the related technology, no effective solution is available at present.

Disclosure of Invention

The invention provides a method and a device for tunnel convergence, which at least solve the problem of slow convergence of an mLDP tunnel in an MBB scene in the related technology.

According to an aspect of the present invention, there is provided a method of tunnel convergence, including:

a leaf node of a label forwarding path tunnel sends a label mapping message which does not carry an MBB mark to an upstream node which updates the inactive state on a first link at present, wherein the label mapping message is used for indicating that the upstream node is in an MBB notification message waiting state after finishing;

the leaf node setting the upstream control block in the inactive state to the upstream control block in the active state;

and the leaf node transmits forwarding information through the first link.

Further, after the leaf node issues forwarding information through the first link, the method includes:

and the leaf node sends label revocation information to an upstream node of a second link, and deletes forwarding information on the second link, wherein the second link is a link to which the leaf node belongs before the first link is established.

According to another aspect of the present invention, there is also provided a method of tunnel convergence, including:

receiving a label mapping message which is used for updating leaf nodes on a first link and does not carry MBB marks by an intermediate node of a label forwarding path tunnel, wherein the label mapping message is used for indicating that the intermediate node is in an MBB notification message waiting state after finishing;

the intermediate node updates the downstream control block information according to the label mapping information;

and the intermediate node transmits forwarding information through the first link.

Further, the method further comprises:

checking whether the intermediate node has an upstream control block in an inactive state, and sending a label mapping message without an MBB mark to the upstream node of the intermediate node under the condition that the upstream control block is not activated;

the intermediate node sets the upstream control block in the inactive state to the upstream control block in the active state.

Further, after the intermediate node issues forwarding information through the first link, the method includes:

the intermediate node sends MBB notification information to the leaf nodes.

According to another aspect of the present invention, there is also provided an apparatus for tunnel convergence, including:

a sending module, configured to send, by a leaf node of a label forwarding path tunnel, a label mapping message that does not carry an MBB flag to an upstream node that currently updates an inactive state on a first link, where the label mapping message is used to indicate that the upstream node ends in an MBB notification message waiting state;

a first setting module for the leaf node to set an upstream control block in an inactive state to an upstream control block in an active state;

and the first forwarding module is used for issuing forwarding information by the leaf node through the first link.

Further, the apparatus further comprises:

a revocation module, configured to send, by the leaf node, label revocation information to an upstream node of a second link, and delete forwarding information on the second link to which the leaf node belongs, where the second link is a link to which the leaf node belongs before the first link is established.

a receiving module, configured to receive, by an intermediate node of a label forwarding path tunnel, a label mapping message that does not carry an MBB flag and that currently updates a leaf node on a first link, where the label mapping message is used to indicate that the intermediate node ends in an MBB notification message waiting state;

an updating module, configured to update, by the intermediate node, downstream control block information according to the tag mapping information;

and the second forwarding module is used for issuing forwarding information by the intermediate node through the first link.

Further, the apparatus further comprises:

a checking module, configured to check whether the intermediate node has an upstream control block in an inactive state, and send a label mapping message that does not carry an MBB label to an upstream node of the intermediate node when the upstream control block in the inactive state exists;

a second setting module, configured to set, by the intermediate node, the upstream control block in the inactive state to the upstream control block in the active state.

Further, the apparatus further comprises:

a notification module, configured to send, by the intermediate node, MBB notification information to the leaf node.

According to the invention, the leaf node of the label forwarding path tunnel sends the label mapping message without carrying the MBB mark to the upstream node which updates the inactive state on the first link at present, the label mapping message is used for indicating that the upstream node is in the waiting state of the MBB notification message, the leaf node sets the upstream control block in the inactive state as the upstream control block in the active state, and the leaf node issues the forwarding information through the first link, so that the problem of slow convergence of the mLDP tunnel in the MBB scene is solved, and the rapid convergence of the mLDP tunnel is realized.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a diagram illustrating a typical MVPN networking in the related art;

fig. 2 is a diagram illustrating a typical mLDP networking in the related art;

FIG. 3 is a diagram illustrating a typical MBB scenario networking in the related art;

FIG. 4 is a flowchart of a method of tunnel convergence according to an embodiment of the present invention;

FIG. 5 is a flowchart II of a method of tunnel convergence according to an embodiment of the present invention;

fig. 6 is a first block diagram of a tunnel convergence apparatus according to an embodiment of the present invention;

FIG. 7 is a block diagram of a tunnel convergence apparatus according to an embodiment of the present invention;

FIG. 8 is a first flowchart illustrating the operation at the leaf node LSR4 in accordance with the preferred embodiment of the present invention;

fig. 9 is a first flowchart illustrating the operation at the intermediate node LSR3 in accordance with the preferred embodiment of the present invention;

fig. 10 is a flowchart illustrating operation at intermediate node LSR3 in accordance with a preferred embodiment of the present invention as shown in fig. two;

fig. 11 is a diagram illustrating the operation of the leaf node LSR4 in accordance with the preferred embodiment of the present invention.

Detailed Description

The invention will be described in detail hereinafter with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

In this embodiment, a method for tunnel convergence is provided, and fig. 4 is a flowchart of a method for tunnel convergence according to an embodiment of the present invention, as shown in fig. 4, the flowchart includes the following steps:

step S402, a leaf node of a label forwarding path tunnel sends a label mapping message without an MBB mark to an upstream node which updates the inactive state on a first link at present, wherein the label mapping message is used for indicating that the upstream node is in an MBB notification message waiting state after finishing;

step S404, the leaf node sets the upstream control block in the inactive state as the upstream control block in the active state;

step S406, the leaf node issues forwarding information through the first link.

Through the steps, the leaf node of the label forwarding path tunnel sends the label mapping message without the MBB label to the upstream node which updates the inactive state on the first link at present, the leaf node sets the upstream control block in the inactive state as the upstream control block in the active state, and the leaf node issues the forwarding information through the first link, so that the problem of slow convergence of the mLDP tunnel in the MBB scene is solved, and the rapid convergence of the mLDP tunnel is realized.

In the embodiment of the present invention, after the leaf node issues the forwarding information through the first link, the leaf node sends the label revocation information to the upstream node of the second link, and deletes the forwarding information on the second link to which the leaf node belongs, where the second link is the link to which the leaf node belongs before the first link is established.

In this embodiment, a method for tunnel convergence is further provided, and fig. 5 is a second flowchart of the method for tunnel convergence according to the embodiment of the present invention, as shown in fig. 5, the flowchart includes the following steps:

step S502, an intermediate node of a label forwarding path tunnel receives a label mapping message which updates a leaf node on a first link at present and does not carry an MBB mark, wherein the label mapping message is used for indicating that the intermediate node is in an MBB notification message waiting state after finishing;

step S504, the intermediate node updates the downstream control block information according to the label mapping information;

step S506, the intermediate node issues forwarding information through the first link.

Through the steps, the intermediate node of the label forwarding path tunnel receives the label mapping message which updates the leaf node on the first link at present and does not carry the MBB mark, the label mapping message is used for indicating that the intermediate node is in the waiting state of the MBB notification message, the intermediate node updates the downstream control block information according to the label mapping message, and the intermediate node issues the forwarding message through the first link, so that the problem of slow convergence of the mLDP tunnel in the MBB scene is solved, and the rapid convergence of the mLDP tunnel is realized.

In this embodiment, it is checked whether the intermediate node has an upstream control block in an inactive state, and if there is an inactive upstream control block, a tag mapping message not carrying an MBB flag is sent to the upstream node of the intermediate node, and the intermediate node sets the upstream control block in the inactive state as the upstream control block in the active state.

In this embodiment, after the intermediate node issues forwarding information through the first link, the method includes: the intermediate node sends MBB notification information to the leaf node.

In this embodiment, a device for tunnel convergence is further provided, and the device is used to implement the foregoing embodiments and preferred embodiments, which have already been described and are not described again. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Fig. 6 is a block diagram of a first apparatus for tunnel convergence according to an embodiment of the present invention, as shown in fig. 6, the apparatus includes:

a sending module 62, configured to send, to an upstream node that currently updates an inactive state on a first link, a label mapping message that does not carry an MBB flag by a leaf node of a label forwarding path tunnel, where the label mapping message is used to indicate that the upstream node is in an MBB notification message waiting state after finishing;

a first setting module 64 for the leaf node to set the upstream control block in an inactive state to the upstream control block in an active state;

and the first forwarding module 66 is used for the leaf node to issue forwarding information through the first link.

By the device, the leaf node of the label forwarding path tunnel sends the label mapping message without the MBB label to the upstream node which updates the inactive state on the first link at present, the leaf node sets the upstream control block in the inactive state as the upstream control block in the active state, and the leaf node issues the forwarding information through the first link, so that the problem of slow convergence of the mLDP tunnel in the MBB scene is solved, and the rapid convergence of the mLDP tunnel is realized.

In this embodiment, the apparatus further comprises: and the revocation module is used for sending label revocation information to an upstream node of a second link by the leaf node and deleting forwarding information on the second link, wherein the second link is a link to which the leaf node belongs before the first link is established.

Fig. 7 is a block diagram of a second structure of a tunnel convergence apparatus according to an embodiment of the present invention, as shown in fig. 7, the apparatus includes:

a receiving module 72, configured to receive, by an intermediate node of a label forwarding path tunnel, a label mapping message that does not carry an MBB flag and that currently updates a leaf node on a first link, where the label mapping message is used to indicate that the intermediate node is in an MBB notification message waiting state after finishing;

an updating module 74, configured to update, by the intermediate node, downstream control block information according to the label mapping information;

and a second forwarding module 76, configured to send forwarding information to the intermediate node through the first link.

By the device, the intermediate node of the label forwarding path tunnel receives the label mapping message which updates the leaf node on the first link at present and does not carry the MBB mark, the label mapping message is used for indicating that the intermediate node is in the waiting state of the MBB notification message, the intermediate node updates the downstream control block information according to the label mapping message, and the intermediate node issues the forwarding message through the first link, so that the problem of slow convergence of the mLDP tunnel in the MBB scene is solved, and the rapid convergence of the mLDP tunnel is realized.

In this embodiment, the apparatus further comprises:

a second setting module for the intermediate node to set the upstream control block in the inactive state to the upstream control block in the active state

In this embodiment, the apparatus further comprises:

and the notification module is used for sending MBB notification information to the leaf node by the intermediate node.

The present invention will be described in detail below with reference to preferred examples and embodiments.

The preferred embodiment provides a method for rapidly converging an mLDP tunnel in an mbl scenario in an mLDP, which aims to solve the problem that tunnel switching can be realized only after the MBB is disabled and the MBB needs to wait for timeout, so that the tunnel can be immediately switched to a new link after the MBB is disabled; and the phenomenon that a loop and even a flow black hole are caused by too low tunnel convergence speed is avoided.

The technical scheme realized by the preferred embodiment comprises the following contents:

if the leaf node has an upstream control block in inactive state, the MBB is disabled:

1. the leaf node sets a new upstream control block of the inactive as an active, transmits and forwards the new upstream control block without waiting for MBB overtime, and sends a label mapping message without carrying an MBB mark to the upstream of the inactive again so as to prevent the new upstream from possibly being in an MBB notification message waiting state until the MBB overtime;

2. the leaf node simultaneously sends a label canceling message to the upstream of the old active to cancel the old link;

3. when a new upstream receives a label mapping message, the stored downstream control block information needs to be updated again, and at the same time, forwarding needs to be issued, if an inactive upstream control block exists, a label mapping message which does not carry an MBB mark also needs to be sent to the upstream until a tunnel root node is reached, and new link establishment is completed;

if the intermediate node has an upstream control block at inactive, the MBB is disabled:

1. the intermediate node sets an upstream control block of the inactive as an active, transmits and forwards the upstream control block, and sends a label mapping message which does not carry the MBB mark to the upstream of the inactive again;

2. sending an MBB notification message to the downstream to prevent the downstream from being in a state of waiting for the MBB notification message until the MBB is overtime;

3. the switching from the old link to the new link can be immediately completed after the downstream receives the MBB notification message without waiting for the MBB overtime;

the networking and configuration of the preferred embodiment are as follows:

1) interfaces of LSR1 and LSR4, LSR1 and LSR2, LSR2 and LSR3, and LSR3 and LSR4 are directly connected respectively;

2) mLDP, LDP and other related configurations are configured on LSR1 and LSR4, an mLDP tunnel LSR4-LSR1 is established, the LSR1 is a tunnel root node, and the LSR4 is a tunnel leaf node;

3) mLDP MBB is enabled on LSR2, LSR3 and LSR4 respectively; and configuring MBB waiting time; MBB is not enabled on LSR 1;

the behavior of each node when the leaf node enables the MBB and the middle node enables the MBB is further explained as follows:

leaf node LSR4 De-Enable MBB

Fig. 8 is a first flowchart illustrating the operation of the leaf node LSR4 according to the preferred embodiment of the present invention, as shown in fig. 8, including the following steps:

step 801, enabling the MBB on the LSR4, and entering step 802;

step 802, the LSR4 sends a label mapping message not carrying an MBB label to the upstream of the inactive state, and step 803 is entered;

step 803, the upstream control block in inactive state is set to active, and step 804 is entered;

step 804, the LSR4 issues a new forwarding message, and step 805 is entered;

at step 805, LSR4 sends a label deactivation message upstream to the old and deletes the old forwarding information.

Fig. 9 is a flowchart illustrating the operation of the intermediate node LSR3 according to the preferred embodiment of the present invention, as shown in fig. 9, including the following steps:

step 901, the LSR3 receives the label mapping message without MBB label from LSR4, and enters step 902;

step 902, updating information on the downstream control block, and entering step 903;

step 903, checking whether there is an upstream control block with inactive state, if yes, entering step 904; if not, go to step 905;

step 904, sending a label mapping message not carrying MBB marks to the upstream, and entering step 905;

step 905, issuing forwarding information, and ending the waiting state of MBB notification message;

the operation on the LSR2 is identical to that on the LSR3, until the tunnel root node LSR1, the whole new tunnel is successfully established, and the fast switching from the old tunnel to the new tunnel is completed.

Intermediate node LSR3 de-enables MBBs

Fig. 10 is a second flowchart illustrating the operation of the intermediate node LSR3 according to the preferred embodiment of the present invention, as shown in fig. 10, including the following steps:

step 1001, enabling the MBB on the LSR3, and entering step 1002;

step 1002, the LSR3 sends a label mapping message not carrying an MBB label to the upstream of the inactive state, and step 1003 is entered;

step 1003, setting the upstream control block in the inactive state to active, and entering step 1004;

step 1004, issuing forwarding information, and entering step 1005;

step 1005, sends an MBB notify message to downstream LSR 4.

Fig. 11 is a diagram illustrating a second operation flow at the leaf node LSR4 according to the preferred embodiment of the present invention, as shown in fig. 11, including the following flows:

step 1101, receiving an MBB notification message sent by the upstream LSR3, entering step 1102;

step 1102, as the same operation is performed after the MBB notification message is received before the present invention, the MBB notification message is no longer continuously in a waiting state, the old tunnel is cancelled, new forwarding information is issued, and the tunnel completes the fast switch from old to new.

Through the above description of the embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but the former is a better implementation mode in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (e.g., ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal device (e.g., a mobile phone, a computer, a server, or a network device) to execute the method according to the embodiments of the present invention.

The embodiment of the invention also provides a storage medium. Optionally, in this embodiment, the storage medium may be configured to store program codes for executing the method steps of the above embodiment:

optionally, in this embodiment, the storage medium may include, but is not limited to: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.

Optionally, in this embodiment, the processor executes the method steps of the above embodiments according to the program code stored in the storage medium.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method of tunnel convergence, comprising:

a leaf node of a label forwarding path tunnel sends a label mapping message which does not carry a built-before-torn MBB mark to an upstream node which is currently updated in an inactive state on a first link, wherein the label mapping message is used for indicating that the upstream node is in an MBB notification message waiting state after finishing;

and the leaf node transmits forwarding information through the first link.

2. The method of claim 1, wherein after the leaf node transmits forwarding information via the first link, the method comprises:

3. A method of tunnel convergence, comprising:

the intermediate node updates the downstream control block information according to the label mapping message;

4. The method of claim 3, further comprising:

5. The method of claim 3, wherein after the intermediate node issues forwarding information over the first link, the method comprises:

the intermediate node sends MBB notification information to the leaf nodes.

6. An apparatus for tunnel convergence, comprising:

a sending module, configured to send, to an upstream node that currently updates an inactive state on a first link, a label mapping message that does not carry a first-build-before-tear-down MBB flag by a leaf node of a label forwarding path tunnel, where the label mapping message is used to indicate that the upstream node ends in an MBB notification message waiting state;

7. The apparatus of claim 6, further comprising:

8. An apparatus for tunnel convergence, comprising:

an updating module, configured to update, by the intermediate node, downstream control block information according to the tag mapping message;

9. The apparatus of claim 8, further comprising:

10. The apparatus of claim 8, further comprising: