CN109067656B

CN109067656B - Method for accelerating LDP session reconstruction and label switching routing equipment

Info

Publication number: CN109067656B
Application number: CN201810916856.1A
Authority: CN
Inventors: 陈传华
Original assignee: Ruijie Networks Co Ltd
Current assignee: Ruijie Networks Co Ltd
Priority date: 2018-08-13
Filing date: 2018-08-13
Publication date: 2021-05-18
Anticipated expiration: 2038-08-13
Also published as: CN109067656A

Abstract

The invention discloses a method for accelerating LDP session reconstruction and label switching routing equipment, wherein the method comprises the following steps: a first LSR receives a hello message sent by a second LSR establishing a session with the first LSR through a first direct connection port, wherein the hello message carries an identifier REMOTE-LSR-ID list of label switching routing equipment of an opposite end; judging whether the REMOTE-LSR-ID list comprises the LSR-ID of the REMOTE-LSR-ID list; if not, disassociating the first adjacency from the session; the first adjacency is the adjacency established by the first LSR and the second LSR through the first direct connection port; and judging whether the session is associated with other neighbors of the session, and if not, closing the session. The embodiment of the invention can solve the problems of longer LDP neighbor residual session convergence time and slower LDP session reconstruction in the prior art.

Description

Method for accelerating LDP session reconstruction and label switching routing equipment

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method for accelerating LDP session reestablishment and a label switching routing device.

Background

Multi-Protocol Label Switching (MPLS) is a technology for implementing packet forwarding through Label actions, wherein a Label Distribution Protocol (LDP) is a Label Distribution Protocol applied to establish an MPLS network.

LDP is used for Label Switching Router (LSR) discovery of potential LDP neighbors. The neighbor establishment of LDP comprises two processes of adjacency discovery and session establishment: firstly, the LSR sends UDP Hello message identification adjacency (adjacency) mutually in a mode of broadcasting messages through a direct connection interface, then TCP connection negotiation session establishment (session) is initiated, and neighbor (neighbor) establishment is completed.

The LDP keep-alive mechanisms comprise two keep-alive mechanisms, one is adjacent UDP hello message keep-alive, and the other is session TCP keepalive message keep-alive. Under the default condition, the interface adjacent to the Hello message sends the message once every 5 seconds, and the time is overtime for 15 seconds; the conversation Keepalive message is sent once every 15 seconds, and the time is overtime for 45 seconds.

If the session of the neighbor at one end is closed (down), the LDP session is deleted, and the other neighbor does not sense that the session of the opposite end is closed in time, a new session can be reestablished only after Keepalive is overtime. This situation takes a long time to re-establish, which can cause long service traffic interruptions.

Disclosure of Invention

The embodiment of the invention provides a method for accelerating LDP session reconstruction and an LSR (Label switched router), which are used for solving the problems of long residual session convergence time of LDP neighbors and slow LDP session reconstruction in the prior art.

A method for accelerating LDP session reestablishment, the method is applied to a label switching routing device (LSR) in an MPLS network, and the method comprises the following steps:

a first LSR receives a hello message sent by a second LSR establishing a session with the first LSR through a first direct connection port, wherein the hello message carries an identifier REMOTE-LSR-ID list of label switching routing equipment of an opposite end;

judging whether the REMOTE-LSR-ID list comprises the LSR-ID of the REMOTE-LSR-ID list;

if not, disassociating the first adjacency from the session; the first adjacency is the adjacency established by the first LSR and the second LSR through the first direct connection port;

and judging whether the session is associated with other neighbors of the session, and if not, closing the session.

Preferably, the method further comprises:

if yes, sending a hello message; and the REMOTE-LSR-ID list carried by the hello message comprises the LSR-ID of the second LSR.

Preferably, after closing the session, the method further comprises:

upon completion of session reestablishment, associating the session with the first adjacency;

and sending a hello message to the second LSR through the first direct connection port, wherein a REMOTE-LSR-ID list carried by the hello message comprises the LSR-ID of the second LSR.

Preferably, when the session establishment is completed, the method further includes:

when the first LSR receives a hello message of which the REMOTE-LSR-ID list does not comprise the LSR-ID of the first LSR for the first time through a third direct connection interface, associating a second adjacency corresponding to the third direct connection interface with the session; the hello message of which the REMOTE-LSR-ID list does not comprise the self LSR-ID is sent to the second LSR;

sending a hello message to the second LSR through the third direct connection interface, wherein a REMOTE-LSR-ID list carried by the hello message comprises an LSR-ID of the second LSR;

and receiving the hello message sent by the second LSR, and keeping alive by judging whether a REMOTE-LSR-ID list in the hello message comprises the self LSR-ID after a hello timeout period.

when a session of a second LSR is closed, the second LSR disassociates an adjacency associated with the session;

and the second LSR sends a hello message to a first LSR establishing the session with the second LSR through a second direct connection interface, wherein a REMOTE-LSR-ID list carried by the hello message does not include the LSR-ID of the first LSR.

Preferably, the method further comprises:

when a REMOTE-LSR-ID list carried by a hello message sent by the first LSR and received through the second direct connection interface comprises an LSR-ID of the REMOTE-LSR-ID list, judging whether the session is reestablished and is associated with a first adjacency, wherein the first adjacency is the adjacency established by the second LSR and the first LSR through the second direct connection interface;

and if so, sending a hello message, wherein a REMOTE-LSR-ID list carried by the hello message comprises the LSR-ID of the first LSR.

the second LSR sends a hello message to the first LSR through a fourth direct connection interface for the first time, and an REMOTE-LSR-ID list carried by the hello message does not include the LSR-ID of the first LSR;

when receiving a hello message that a REMOTE-LSR-ID list sent by the first LSR comprises an LSR-ID of the second LSR, associating a second adjacency corresponding to the fourth direct connection interface with the session;

sending a hello message to the first LSR through the fourth direct connection interface, wherein a REMOTE-LSR-ID list carried by the hello message comprises an LSR-ID of the first LSR;

and receiving the hello message sent by the first LSR, and keeping alive by judging whether a REMOTE-LSR-ID list in the hello message comprises the self LSR-ID after a hello timeout period.

A label switched routing device, LSR, comprising: a receiving and sending unit, a first judging unit, an adjacent session association unit, a second judging unit and a session closing unit; wherein the content of the first and second substances,

the receiving and sending unit is used for receiving a hello message sent by a second LSR establishing a session with the receiving and sending unit through a first direct connection port of the LSR, wherein the hello message carries an identifier REMOTE-LSR-ID list of label switching routing equipment of an opposite end;

the first judging unit is used for judging whether the REMOTE-LSR-ID list comprises the self LSR-ID;

said adjacency session association unit for disassociating the first adjacency from said session when said REMOTE-LSR-ID list does not include the own LSR-ID; the first adjacency is an adjacency established by the LSR and the second LSR through the first direct connection port;

the second determination unit is configured to determine whether the session is associated with another neighbor of the second determination unit after the first neighbor is disassociated from the session;

the session closing unit is configured to close the session when the session is not associated with other neighbors.

Preferably, the transceiver unit is further configured to send a hello packet when the REMOTE-LSR-ID list includes the self LSR-ID; and the REMOTE-LSR-ID list carried by the hello message comprises the LSR-ID of the second LSR.

Preferably, the adjacency session association unit is further configured to associate the session with the first adjacency after session reestablishment is completed;

the transceiver unit is further configured to send a hello packet to the second LSR through the first direct connection port, where a list of REMOTE-LSR-IDs carried in the hello packet includes the LSR-ID of the second LSR.

Preferably, when the session is established and the transceiver unit receives a hello packet whose REMOTE-LSR-ID list does not include the LSR-ID of the transceiver unit for the first time through a third direct connection interface of the LSR, the adjacency session association unit is further configured to associate a second adjacency corresponding to the third direct connection interface with the session; wherein, the hello message of which the REMOTE-LSR-ID column does not include the LSR-ID of the REMOTE-LSR-ID column is sent by the second LSR;

the transceiver unit is further configured to send a hello packet to the second LSR through the third direct connection interface, where a list of REMOTE-LSR-IDs carried by the hello packet includes an LSR-ID of the second LSR; and the first judging unit is further configured to receive a hello packet sent by the second LSR, and after a hello timeout period elapses, trigger the first judging unit to keep alive by judging whether a REMOTE LSR-ID list in the hello packet includes a self LSR-ID.

An LSR, the LSR comprising: an adjacent session association unit and a transmitting/receiving unit; wherein the content of the first and second substances,

the adjacent session association unit is used for disassociating the adjacent associated with the session when the session is closed;

the transceiver unit is configured to send a hello packet to a first LSR that establishes the session with the first LSR through a second direct connection interface of the LSR, where a list of REMOTE-LSR-IDs carried in the hello packet does not include the LSR-ID of the first LSR.

Preferably, the LSR further comprises: a second determining unit, configured to determine whether the session is reestablished and associated with a first adjacency when a list of REMOTE-LSR-IDs carried by hello packets sent by the first LSR and received by the transceiver unit through the second direct connection interface includes an LSR-ID of the transceiver unit, where the first adjacency is an adjacency established by the LSR and the first LSR through the second direct connection interface;

the transceiver unit is further configured to send a hello packet if the hello packet is associated, where a list of REMOTE-LSR-IDs carried by the hello packet includes the LSR-ID of the first LSR.

Preferably, the LSR further includes a first determining unit;

the transceiver unit is further configured to send a hello packet to the first LSR through a fourth direct connection interface for the first time when the session is established, where a list of REMOTE-LSR-IDs carried by the hello packet does not include an LSR-ID of the first LSR;

the neighbor session associating unit is further configured to associate a second neighbor corresponding to the fourth direct connection interface with the session when the transceiver unit receives a hello packet whose REMOTE-LSR-ID list sent by the first LSR includes an own LSR-ID;

the transceiver unit is further configured to send a hello packet to the first LSR through the fourth direct interface, where a list of REMOTE-LSR-IDs carried by the hello packet includes an LSR-ID of the first LSR; and the first judging unit is also used for receiving a hello message sent by the first LSR and triggering the first judging unit to judge whether the REMOTE-LSR-ID list in the hello message comprises the self LSR-ID for keeping alive after a hello timeout period is passed.

The invention has the following beneficial effects:

the method for accelerating LSP session reconstruction and the LSR provided by the embodiment of the invention judge whether a REMOTE-LSR-ID list carried by a hello message contains the LSR-ID of the hello message or not by receiving the hello message sent by the LSR which establishes the session with the LSR, if not, the session of the opposite end is abnormal, at the moment, the adjacency established with the opposite end is disassociated from the session, and whether the session is associated with other adjacencies at the local end is judged, if not, the session is closed, so that the abnormal session of the opposite end can be quickly sensed, the LDP neighbor residual session convergence time can be shortened, and the LDP session reconstruction is accelerated.

Drawings

FIG. 1 is a flowchart illustrating a method for accelerating LDP session reestablishment according to an embodiment of the present invention;

fig. 1a is a schematic diagram of a format of a hello packet in the embodiment of the present invention;

FIG. 2 is a flowchart of a method for reestablishing an LDP session according to an embodiment of the present invention;

FIG. 3 is a flow chart of LDP session neighbor newly-added adjacency in the embodiment of the present invention;

FIG. 4 is a flowchart illustrating another embodiment of a method for accelerating LDP session reestablishment according to the present invention;

FIG. 5 is a flowchart of another embodiment of a method for reestablishing an LDP session according to the present invention;

FIG. 6 is a flow chart of another embodiment of LDP session neighbor newly-added adjacency in the present invention;

FIG. 7 is an interaction flow diagram for establishing LDP session neighbors in an embodiment of the present invention;

FIG. 8 is an interaction flow diagram of LDP session neighbor newly-added adjacency in the embodiment of the present invention;

FIG. 9 is an interaction flowchart of a method for accelerating LDP session reestablishment according to an embodiment of the present invention;

FIG. 10 is a diagram illustrating the structure of an LSR according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of another embodiment of an LSR in an embodiment of the present invention.

Detailed Description

Aiming at the problems of longer convergence time of LDP neighbor residual sessions and slower reconstruction of LDP sessions in the prior art, the method for accelerating the reconstruction of the LDP sessions provided by the embodiment of the invention has the advantages that firstly, each LSR has a unique LSR-ID, only one session is established between the LSR and the LSR, but each LSR can have a plurality of interfaces, and a plurality of direct connection interfaces between the LSR and the LSR can be connected to establish a plurality of adjacencies; the LDP adjacency discovery and session establishment belong to an association relationship, and the session is established on the basis of adjacency. One session can be associated with a plurality of adjacencies, one adjacency can be associated with only one session, the establishment of the session needs to have the adjacency, and the session without the adjacency needs to be closed; secondly, the invention adds REMOTE-LSR-ID field in the hello message by using a UDP hello message TLV extension mechanism in the standard LDP, wherein the REMOTE-LSR-ID field can be an LSR-ID list and comprises all adjacent opposite end LSR-IDs associated with the session, and the reconstruction of the LDP session is accelerated by judging a REMOTE-LSR-ID list interface.

The method of the present invention is applied to an MPLS network, where the MPLS network includes a plurality of LSRs, and for convenience of description, two LSRs are taken as an example for description, and are respectively denoted as a first LSR and a second LSR, and the flow of the method is shown in fig. 1, and is described from the side of the first LSR, and the following steps are performed:

step 11, a first LSR receives a hello message sent by a second LSR establishing a session with the first LSR through a first direct connection interface, wherein the hello message carries an identifier REMOTE-LSR-ID list of label switching routing equipment of an opposite terminal;

here, the first LSR and the second LSR have already completed the adjacency discovery and session establishment, and both have been neighbors to each other, and can keep alive by sending hello packets to each other, where the hello packets have extended the REMOTE-LSR-ID list by TLV, and the specific structure is shown in fig. 1 a.

Step 12, judging whether the REMOTE-LSR-ID list comprises the self LSR-ID;

keeping alive by judging whether REMOTE-LSR-ID carried in the hello message includes self LSR-ID, if yes, the conversation between the first LSR and the second LSR is not abnormal, at the moment, the hello message can be sent to the second LSR, and a REMOTE-LSR-ID list carried by the sent hello message includes the LSR-ID of the second LSR.

Step 13, if not, disassociating the first adjacency from the session; the first adjacency is the adjacency established by the first LSR and the second LSR through the first direct connection port;

if not, the session of the second LSR is abnormal, and the first adjacency and the session are disassociated, so that the LSR-ID of the first LSR is not included in the hello message sent by the second LSR; here, the first LSR proactively disassociates the first adjacency from the session.

And step 14, judging whether the session is associated with other adjacent nodes of the session, and if not, closing the session.

After the neighbor establishment is completed, each LSR records the association list of the session and the adjacency, and after the session is disassociated from one adjacency, the LSR judges whether the session is associated with other neighbors of the LSR according to the association list, if not, the session is actively closed, so that the abnormal session of the opposite terminal can be quickly sensed and closed, and the new session can be reestablished without waiting for a Keepalive timeout in the prior art.

As shown in fig. 2, after closing the session, the method further includes:

step 21, after the session is reestablished, associating the session with the first adjacency;

after the first LSR closes the abnormal conversation of the second LSR (opposite end), the conversation is established again with the second LSR, and before the conversation is reestablished, a REMOTE-LSR-ID list carried by a hello message sent by the first LSR does not include the LSR-ID of the second LSR; when the session reestablishment of the local end is completed, the session is associated with the first adjacency, and the first LSR uses the LSR-ID of the opposite end as the adjacency identifier adj-ID of the first adjacency, so that after the session is associated with the first connection, the LSR-ID of the second LSR is written into the REMOTE LSR-ID list of the hello message, that is, when the first LSR sends the hello message again after the association of the first adjacency and the session is completed, the REMOTE LSR-ID list in the hello message only includes the LSR-ID of the second LSR.

And step 22, sending a hello message to the second LSR through the first direct connection port, wherein a REMOTE-LSR-ID list carried by the hello message includes the LSR-ID of the second LSR.

After the session and the first adjacency association are completed, the hello message sent by the first LSR to the second LSR comprises the LSR-ID of the second LSR; this is because the contents of the LSR-ID included in the REMOTE-LSR-ID list in the hello message can be determined from the adj-ID after the session is associated with the adjacency.

Further, referring to fig. 3, a flow chart when the first LSR and the second LSR have established a neighbor through the first neighbor and have added a new neighbor on the basis of the neighbor is shown in fig. 3, where the method includes:

step 31, when the first LSR receives a hello packet whose REMOTE-LSR-ID list does not include the LSR-ID of itself for the first time through a third direct connection interface, associating a second adjacency corresponding to the third direct connection interface with the session; the hello message of which the REMOTE-LSR-ID list does not comprise the self LSR-ID is sent to the second LSR;

here, the first LSR has established a session with the second LSR, the session being associated with the first adjacency; when the first LSR first receives a hello packet with the list of REMOTE-LSR-IDs excluding its own LSR-ID via the third direct interface, it indicates that the first LSR may find a new adjacency from the second LSR, and then associates the established session with the new adjacency, and for convenience of expression, the new adjacency is denoted as a second adjacency whose adj-ID is the LSR-ID of the second LSR.

Step 32, sending a hello message to the second LSR through the third direct connection interface, wherein a REMOTE-LSR-ID list carried by the hello message includes an LSR-ID of the second LSR;

a hello message sent to a second LSR through a third direct connection interface carries a REMOTE-LSR-ID list comprising the LSR-ID of the second LSR; and the first LSR takes the LSR-ID of the opposite end as the adjacency identifier adj-ID of the second adjacency, so that after the session is associated with the second adjacency, the LSR-ID of the second LSR is written into a REMOTE-LSR-ID list of the hello message, namely after the second adjacency is associated with the session, the REMOTE-LSR-ID list in the hello message comprises the LSR-ID of the second LSR when the first LSR sends the hello message through the third direct connection interface again.

And step 33, receiving the hello message sent by the second LSR, and keeping alive by judging whether the REMOTE-LSR-ID list in the hello message includes the self LSR-ID after a hello timeout period.

Here, within the first hello timeout period, directly ignoring the REMOTE-LSR-ID list in the hello message, that is, not judging the REMOTE-LSR-ID list, so as to avoid causing adjacent association session oscillation; after the first hello timeout period, keep alive is performed by judging whether the REMOTE-LSR-ID list in the hello message includes the self LSR-ID, and the specific process refers to the method flow shown in FIG. 2.

The above embodiments are presented from the first LSR side, and in order to explain the present invention in more detail, the present invention is described below from the second LSR side.

Fig. 4 shows a flow chart of another embodiment of the method for accelerating LDP session reestablishment, which is described from the second LSR side and implemented as follows:

step 41, when the session of the second LSR is closed, the second LSR disassociates the adjacency associated with the session;

here, the first LSR and the second LSR have already completed the adjacency discovery and the session establishment, and both have been neighbors, and can keep alive by sending hello messages to each other, when the session between the second LSR and the first LSR is down at the second LSR end, the second LSR will completely disassociate the adjacency associated with the session according to the association list of the session and the adjacency recorded by itself.

And 42, the second LSR sends a hello message to a first LSR which establishes the session with the second LSR through a second direct connection interface, wherein a REMOTE-LSR-ID list carried by the hello message does not include the LSR-ID of the first LSR.

Here, the second direct connection interface establishes a first adjacent direct connection interface for the second LSR and the first LSR;

when the session is disassociated from the adjacency, and the second LSR sends a hello message through the adjacency, the REMOTE-LSR-ID list carried by the hello message does not include the LSR-ID of the first LSR, so that after an opposite end receives the hello message of which the REMOTE-LSR-ID list does not include the LSR-ID of the first LSR, the session associated with the adjacency can be quickly sensed to be abnormal.

As shown in fig. 5, session reestablishment is performed between the second LSR and the first LSR, and hello packets between the second LSR and the first LSR continue to interact with each other, where the method further includes:

step 51, when a list of REMOTE-LSR-IDs carried by hello messages sent by the first LSR and received through the second direct connection interface includes the LSR-ID of the REMOTE-LSR-ID, judging whether the session is rebuilt and is associated with a first adjacency, wherein the first adjacency is the adjacency established by the second LSR and the first LSR through the second direct connection interface;

when the REMOTE-LSR-ID list carried by the hello message received by the second LSR includes the self LSR-ID, the fact that the first LSR completes the session reconstruction and associates the session with the first adjacent node again is indicated, at this time, whether the home terminal completes the session reconstruction and associates the home terminal with the first adjacent node needs to be judged, and if not, the hello message of which the REMOTE-LSR-ID list does not include the LSR-ID of the first LSR is still replied.

And step 52, if the association is carried out, sending a hello message, wherein the REMOTE-LSR-ID list carried by the hello message comprises the LSR-ID of the first LSR.

Further, referring to fig. 6, a flow when the first LSR and the second LSR have established a neighbor through the first neighbor and, on the basis of the neighbor, add a new neighbor is illustrated, as shown in fig. 6, when the session establishment is completed, the method further includes:

step 61, the second LSR sends a hello packet to the first LSR through a fourth direct connection interface for the first time, and a REMOTE-LSR-ID list carried by the hello packet does not include the LSR-ID of the first LSR;

here, the first LSR has established a session with the second LSR, the session being associated with the first adjacency; the second LSR in turn wants to establish a new adjacency with the first LSR over the fourth direct interface, which new adjacency is denoted as second adjacency whose adj-ID is the LSR-ID of the first LSR for ease of expression.

Step 62, when receiving a hello packet of which the REMOTE-LSR-ID list sent by the first LSR includes the LSR-ID of the second LSR, associating a second adjacency corresponding to the fourth direct connection interface with the session;

when receiving hello message sent by the first LSR that the list of REMOTE-LSR-ID includes LSR-ID of the second LSR, indicating that the establishment of the second adjacency is completed, the previously established session needs to be associated with the second adjacency.

Step 63, sending a hello message to the first LSR through the fourth direct connection interface, wherein a REMOTE-LSR-ID list carried by the hello message includes the LSR-ID of the first LSR;

the hello message sent to the first LSR through the fourth direct connection interface carries the LSR-ID of the first LSR; this is because the contents of the LSR-ID carried in the hello message can be determined from the adj-ID of the second adjacency after the session is associated with the second adjacency.

And step 64, receiving the hello message sent by the first LSR, and keeping alive by judging whether the REMOTE-LSR-ID list in the hello message comprises the same LSR-ID after a hello timeout period.

Here, within the first hello timeout period, directly ignoring REMOTE-LSR-ID in the hello message, that is, not judging REMOTE-LSR-ID, so as to avoid causing adjacent association session oscillation; after the first hello timeout period, keep alive is performed by judging whether the REMOTE-LSR-ID list in the hello message includes the self LSR-ID, and the specific process refers to the method flow shown in FIG. 2.

The above embodiments are further illustrated below with LSR-A and LSR-B as examples.

Referring to fig. 7, fig. 7 shows an interaction diagram of establishing A neighbor session between LSR- A and LSR-B, as shown in fig. 7, including:

71, in the stage of discovering the adjacency, A hello message is interacted between the LSR-A and the LSR-B, the hello message does not have an LSR-ID of an opposite end, the hello message is normally processed according to the existing protocol, A REMOTE-LSR-ID list of the hello message is ignored, and A new adjacency is discovered.

And 72, normally initiating the TCP connection, negotiating and establishing a session, and finishing the session establishment.

Specifically, the method comprises that the LSR-A actively sends an initialization message negotiation parameter, and the LSR-B receives the parameter and then sends the initialization message and A keepalive message;

73, LSR-B session establishment, sending a hello message, wherein the REMOTE-LSR-ID list of the hello message carries the LSR-ID of the opposite terminal;

if the session of the LSR-A is not established, ignoring A REMOTE-LSR-ID list in A hello message sent by the LSR-B, and if receiving the opposite-end parameters, sending A keepalive message.

74, establishing A session of the LSR-A, and sending A hello message, wherein A REMOTE-LSR-ID list of the hello message carries an LSR-ID of an opposite end;

the adjacency of LSR-B associates the established session and determines the REMOTE-LSR-ID list in the hello message sent by LSR-A for normal keep-alive. The two also transmit the label and the keepalive message to keep alive.

Referring to fig. 8, fig. 8 shows an interaction diagram of adding an adjacency after A neighbor session has been established between LSR- A and LSR-B, as shown in fig. 8, which includes:

81, in A new adjacency discovery stage, the LSR-A and the LSR-B respectively send LSR-ID without an opposite end in A first hello message to the opposite end through each new direct connection interface; and after the Hello messages sent by the respective LSR-A and LSR-B parties, processing the Hello messages according to the existing protocol, ignoring REMOTE-LSR-ID lists carried in the Hello messages and discovering new adjacency.

82, after the new adjacency associates the created session, the next Hello message carries the LSR-ID of the opposite terminal; after identifying a new adjacency and associating the adjacency with a corresponding session, the REMOTE-LSR-ID list is not judged in the Hello timeout period of the first period, so that the oscillation of the adjacency association session is avoided.

And 83, after identifying A hello timeout period of the new adjacency, the LSR-A and LSR-B start to keep alive by judging the REMOTE-LSR-ID list in the received hello message.

Referring to fig. 9, fig. 9 is A schematic diagram illustrating interaction between LSR- A and LSR-B to reestablish A session after the end session is closed, as shown in fig. 9, including:

91, establishing neighbor relation and associating session LSR-A and LSR-B, keeping alive by sending hello message, the hello message carrying REMOTE-LSR-ID list.

92, session down of LSR-A, its adjacency is disassociated from the session, and there is no LSR-ID of the opposite end in the REMOTE-LSR-ID list of the transmitted hello message.

93, LSR-B receives the hello message, judges that no local end LSR-ID exists in the REMOTE-LSR-ID list of the hello message, and adjacently disassociates the corresponding session.

And 94, the LSR-B judges that the disassociated session is obtained, and if no other adjacency can be associated, the session is closed.

And 95, the LSR-A and the LSR-B mutually send hello messages, and the hello messages do not have LSR-ID of opposite ends, and new adjacent identification is carried out again.

96, LSR-A and LSR-B reinitiate the TCP connection, reconcile the establishment of the session, and reassociate the session with the adjacency.

97, the respective adjacency and conversation of LSR-A and LSR-B are established, and A hello message is sent mutually, the REMOTE-LSR-ID list in the hello message comprises the LSR-ID of the opposite end, and the REMOTE-LSR-ID is judged to keep alive normally.

Based on the same inventive concept, an embodiment of the present invention provides an LSR, whose structure is shown in fig. 10, including: a transmitting/receiving unit 101, a first determining unit 102, an adjacent session associating unit 103, a second determining unit 104, and a session closing unit 105; wherein the content of the first and second substances,

the transceiver unit 101 is configured to receive a hello packet sent by a second LSR that establishes a session with itself through a first direct access port of the LSR, where the hello packet carries an identifier, REMOTE-LSR-ID, list of an opposite-end label switching router;

the first determining unit 102 is configured to determine whether the list of REMOTE-LSR-IDs includes the own LSR-ID;

said adjacency session association unit 103, configured to disassociate the first adjacency from said session when said REMOTE-LSR-ID list does not include the own LSR-ID; the first adjacency is an adjacency established by the LSR and the second LSR through the first direct connection port;

the second determination unit 104 is configured to determine whether the session is associated with another adjacent node after the first adjacent node is disassociated from the session;

the session closing unit 105 is configured to close the session when the session is not associated with other adjacencies.

Further, the transceiver unit 101 is further configured to send a hello packet when the REMOTE-LSR-ID list includes the self LSR-ID; and the REMOTE-LSR-ID list carried by the hello message comprises the LSR-ID of the second LSR.

Further, the adjacency session association unit 103 is further configured to associate the session with the first adjacency after the session reestablishment is completed;

the transceiver unit 101 is further configured to send a hello packet to the second LSR through the first direct connection port, where a list of REMOTE-LSR-IDs carried in the hello packet includes the LSR-ID of the second LSR.

Further, when the session is established and the transceiver unit 101 receives a hello packet whose REMOTE-LSR-ID list does not include the LSR-ID of the transceiver unit for the first time through a third direct connection interface of the LSR, the adjacency session associating unit 103 is further configured to associate a second adjacency corresponding to the third direct connection interface with the session; wherein, the hello message of which the REMOTE-LSR-ID column does not include the LSR-ID of the REMOTE-LSR-ID column is sent by the second LSR;

the transceiver unit 101 is further configured to send a hello packet to the second LSR through the third direct connection interface, where a list of REMOTE-LSR-IDs carried by the hello packet includes an LSR-ID of the second LSR; and is further configured to receive a hello packet sent by the second LSR, and after a hello timeout period elapses, trigger the first determining unit 102 to perform keep-alive by determining whether a REMOTE LSR-ID list in the hello packet includes a self LSR-ID.

An embodiment of the present invention further provides another embodiment of an LSR, which has a structure as shown in fig. 11, where the LSR includes: adjacency session association section 111 and transmission/reception section 112; wherein the content of the first and second substances,

the adjacency session association unit 111 is configured to disassociate an adjacency associated with a session when the session is closed;

the transceiver unit 112 is configured to send a hello packet to a first LSR that establishes the session with itself through a second direct connection interface of the LSR, where a list of REMOTE-LSR-IDs carried in the hello packet does not include the LSR-ID of the first LSR.

Further, the LSR further includes: a second determining unit 113, configured to determine whether the session is reestablished and associated with a first adjacency when a list of a REMOTE-LSR-ID carried by a hello packet sent by the first LSR and received by the transceiver unit 112 through the second direct connection interface includes a self LSR-ID, where the first adjacency is an adjacency established by the LSR and the first LSR through the second direct connection interface;

the transceiver unit 112 is further configured to send a hello packet if the hello packet is associated, where a list of REMOTE-LSR-IDs carried in the hello packet includes the LSR-ID of the first LSR.

Further, the LSR further includes a first determining unit 114;

the transceiver unit 112 is further configured to send a hello packet to the first LSR through a fourth direct connection interface for the first time when the session is established, where a list of REMOTE-LSR-IDs carried by the hello packet does not include an LSR-ID of the first LSR;

the adjacency session associating unit 111 is further configured to associate a second adjacency corresponding to the fourth direct connection interface with the session when the transceiver unit 112 receives a hello packet that the REMOTE-LSR-ID list sent by the first LSR includes a self LSR-ID;

the transceiver unit 112 is further configured to send a hello packet to the first LSR through the fourth direct interface, where a list of REMOTE-LSR-IDs carried in the hello packet includes an LSR-ID of the first LSR; and is further configured to receive a hello packet sent by the first LSR, and after a hello timeout period elapses, trigger the first determining unit 114 to determine whether a list of REMOTE-LSR-IDs in the hello packet includes a self LSR-ID for keep alive.

It should be understood that the LSR implementation principle and procedure provided by the embodiment of the present invention are similar to those of the embodiments shown in fig. 1 to 9 and described above, and are not described herein again.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While alternative embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following appended claims be interpreted as including alternative embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present invention without departing from the spirit or scope of the embodiments of the invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to encompass such modifications and variations.

Claims

1. A method for accelerating LDP session reestablishment, the method being applied to a label switching routing device (LSR) in an MPLS network, the method comprising:

and judging whether the session is associated with other neighbors of the session, if not, closing the session to accelerate the session reconstruction.

2. The method of claim 1, further comprising:

3. The method of claim 1, wherein after closing the session, the method further comprises:

4. A method according to any of claims 1 to 3, wherein when the session establishment is completed, the method further comprises:

5. A method for accelerating LDP session reestablishment, the method being applied to a label switching routing device (LSR) in an MPLS network, the method comprising:

and the second LSR sends a hello message to a first LSR establishing the session with the second LSR through a second direct connection interface, wherein a REMOTE-LSR-ID list carried by the hello message does not include the LSR-ID of the first LSR so as to inform the first LSR that the session is abnormal.

6. The method of claim 5, further comprising:

7. The method according to claim 5 or 6, wherein when the session establishment is completed, the method further comprises:

8. A label switched routing device, LSR, comprising: a receiving and sending unit, a first judging unit, an adjacent session association unit, a second judging unit and a session closing unit; wherein the content of the first and second substances,

9. The LSR of claim 8, wherein the transceiver unit is further configured to send a hello packet if the REMOTE-LSR-ID list includes its LSR-ID; and the REMOTE-LSR-ID list carried by the hello message comprises the LSR-ID of the second LSR.

10. The LSR of claim 8, wherein the adjacency session association unit is further configured to associate the session with the first adjacency after session reestablishment is completed;

11. The LSR of any of claims 8-10, wherein when the session establishment is completed, the transceiver unit receives a hello packet with a REMOTE LSR-ID list not including its own LSR-ID for the first time through a third direct interface of the LSR, and the adjacency session associating unit is further configured to associate a second adjacency corresponding to the third direct interface with the session; wherein, the hello message of which the REMOTE-LSR-ID column does not include the LSR-ID of the REMOTE-LSR-ID column is sent by the second LSR;

12. An LSR, the LSR comprising: an adjacent session association unit and a transmitting/receiving unit; wherein the content of the first and second substances,

13. The LSR of claim 12, wherein the LSR further comprises: a second determining unit, configured to determine whether the session is reestablished and associated with a first adjacency when a list of REMOTE-LSR-IDs carried by hello packets sent by the first LSR and received by the transceiver unit through the second direct connection interface includes an LSR-ID of the transceiver unit, where the first adjacency is an adjacency established by the LSR and the first LSR through the second direct connection interface;

14. The LSR of claim 12 or 13, further comprising a first determining unit;