CtrMcastComp is the centralised multicast route computation agent.
resets all multicast forwarding entries.
compute-mroutes & (re)computes all multicast forwarding entries.
[source, group]compute-tree & computes a multicast tree for one source to reach all the receivers in a specific group.
[source, group, member]compute-branch & is executed when a receiver joins a multicast group. It could also be invoked by compute-tree when it itself is recomputing the multicast tree, and has to reparent all receivers. The algorithm starts at the receiver, recursively finding successive next hops, until it either reaches the source or RP, or it reaches a node that is already a part of the relevant multicast tree. During the process, several new replicators and an outgoing interface will be installed.
[source, group, member]prune-branch & is similar to compute-branch except the outgoing interface is disabled; if the outgoing interface list is empty at that node, it will walk up the multicast tree, pruning at each of the intermediate nodes, until it reaches a node that has a non-empty outgoing interface list for the particular multicast tree.
Tom Henderson 2011-11-05