Method and apparatus for processing label distribution protocol conversation, label switching router

Abstract

The embodiment of thehe present invention discloses a method and apparatus for processing label distribution protocol conversations, and a label switching router. The method includes steps: when discovering addion of a route in a mode of actively distributing DU label on the downstream, enquiring whether a forwarding equivalence class FEC corresponding with the route, sends label canceling messageto a peer and receives a corresponding label releasing message of the label canceling message or not; when the peer has sent the label canceling message and has received the corresponding label releasing message, or does not have sent the label canceling message, distributing a label for the FEC; sending a label mapping message to the peer, wherein the label mapping message includes the FEC and distributed label. The embodiment of the invention is capable of avoiding that forwarding items of the peers are different due to deletion of the route and rapid addition of the route in a DU mode, ensuring normal forwarding of packets, so as to ensure communication service quality effectively.

Description

technical field [0001] The present invention relates to multi-protocol label switching (Multi-protocol Label Switching, hereinafter referred to as MPLS) technology, in particular to a label distribution protocol session processing method and device, and a label switching router. Background technique [0002] MPLS technology is a new technology that uses labels to guide high-speed and efficient data transmission on an open communication network. MPLS technology can support a variety of network layer protocols, such as: Internet Protocol (Internet Protocol, hereinafter referred to as: IP), Internet Protocol Version 6 (Internet Protocol of Version 6, hereinafter referred to as: IPv6), Internet Packet Exchange (Internet Work Packet Exchange, (hereinafter referred to as: IPX) protocol, etc., compatible with asynchronous transfer mode (Asynchronous Transfer Mode, hereinafter referred to as: ATM), frame relay, Ethernet and other link layer technologies. A network using MPLS is cal...

AI Technical Summary

Problems solved by technology

[0015] According to the existing label switching method, when the first LSR finds that the route FEC192.168.201 / 24 is deleted, in DU mode, the first LSR sends a label withdrawal message to the second LSR, which includes FEC192.168.201 / 24 and label 100, and withdraws For the previously sent label 100, if the first LSR has not received the label release message returned by the second LSR for the label revocation message, the first LSR finds the added route FEC192.168.201 / 24, and sends the second LSR Distribute the label, if the label is the same as the label 100 in the label revocation message, the FTN of the second LSR will establish a forwarding entry of the label 100, and forward the message according to the label 100; and because the first LSR receives When the second LSR responds to the label release message returned by the label revocation message, it will release the label 100. As a result, the local ILM in the first LSR no longer has the incoming label information of FEC192.168.201 / 24, and there is no forwarding table for the incoming label 100. entry, which leads to inconsistency between the forwarding table entries in the first LSR and the second LSR

Similarly, when the label revocation message sent by the first LSR to the second LSR does not carry a label, since the first LSR receives the label release message returned by the second LSR for the label revocation message, it will release the 24 distributed label 100, resulting in the local ILM in the first LSR no longer has the incoming label information of FEC192.168.201 / 24, and there is no forwarding entry for the incoming label 100, which also leads to the forwarding table between the first LSR and the second LSR item inconsistent

When the forwarding entries in the first LSR and the second LSR are inconsistent, when the first LSR receives the packet with the released label 100 sent by the second LSR, it will discard the packet because it cannot obtain the corresponding forwarding information , the packet cannot be forwarded normally, resulting in the interruption of the communication service

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