Patent ID: 6732189
Filing Date: 2004-05-04
Classification: H04L

Abstract:
A method for maintaining the reachability of IP multicast communications across a communications network wit one or more subnetworks wherein each subnetwork comprises at least one node coupled thereto and a node identified as a subnetwork leader, and the communications network comprises one node identified as a network leader, the method comprising the steps of:receiving a host address list containing a list of all the point-to-point addresses of the nodes in a network including at least two subnetworks, and a node in each subnetwork identified as a subnetwork leader; using the host address list for determining which subnetworks the subnetwork leaders are associated therewith; periodically monitoring the reachability of at least one subnetwork leader in the network; and if at least one subnetwork leader for one of the subnetworks in the network become multicast unreachable, then at least one node in the subnetwork associated with the subnetwork leader that has become multicast unreachable performing the steps of: electing a new subnetwork leader for a multicast unreachable subnetwork associated with the subnetwork leader that has become unavailable; and establishing a connection using IP multicast tunneling between a newly elected subnetwork leader for the multicast unreachable subnetwork with at least one other subnetwork leader in the network.