Reroute Extensions to LDP for P2MP LSP
This document describes some extensions to the Label Distribution Protocol (LDP) for the reroute of point to multi-point (P2MP) Label Switched Paths (LSPs) in Multi-Protocol Label Switching (MPLS) networks. The solution relies on LDP only and has no requirement of a multicast routing protocol in the network. Protocol elements and procedures for this solution are described for rerouting a P2MP LSP in the following cases:1)network failure (link or node); 2)a better path emerges (e.g. new link available, metric change);3)planned maintenance. The rerouting mechanism described in this document can minimize the time of traffic disruption when network failure happens. It will also minimize the data duplication and guarantee the traffic continuity during the procedure of rerouting in the last two cases mentioned above.