Enhancements to PIM fast re-route with upstream activation packets

摘要

An upstream activation mechanism provides enhancements to PIM-SM based fast re-route in a multicast communication network, where secondary paths provides redundancy to a multicast tree and are on standby to reduce bandwidth usage when there is no failure in the network. Upon receiving an indication of a loss of connection to the primary path of the multicast tree network, a network node that has a failure-free secondary path to a common source node of the multicast tree sends an activation packet upstream toward the common source node via the failure-free secondary path. The activation packet causes one or more upstream nodes to unblock their respective outgoing interfaces to thereby activate transmission of the multicast data traffic on the failure-free secondary path.

主权项

1. A method performed by a network node in a multicast communication network, the multicast communication network including a multicast tree and a set of secondary paths that are computed prior to failure in the multicast tree, the set of secondary paths provide redundancy to the multicast tree such that multicast data traffic is to be re-routed to one or more of the secondary paths in case of a failure in the multicast tree, the method comprising the steps of:
receiving by the network node an indication of a loss of connection to a primary path of the multicast tree that provides a path between the network node and a common source node; determining that the network node has a failure-free secondary path to the common source node, wherein the failure-free secondary path is computed prior to the loss of connection to the primary path and the failure-free secondary path includes a merge node with an unblocked incoming interface to the failure-free secondary path and a branch node with a blocked outgoing interface to the failure-free secondary path so that the multicast data traffic does not flow on the failure-free secondary path when there is no failure in the multicast communication network to reduce bandwidth usage; and sending an activation packet upstream toward the common source node via the failure-free secondary path to cause an upstream node to unblock an outgoing interface to thereby activate transmission of the multicast data traffic on the failure-free secondary path.