Protecting a MPLS multicast session tree with bounded switchover time

This paper proposes an algorithm to protect a Multiprotocol Label Switching (MPLS) multicast tree from a single link failure with bounded switchover time. Existing protecting algorithms include link protection, path protection, dual tree protection, and redundant tree protection. The problems with these algorithms are that they either provide an unbounded switchover time-meaning that in the case of a link failure, the time it takes for the algorithm to discover and switch the traffic over to a backup path is not predictable-or the bandwidth required for such protection is high. The proposed algorithm provides a guaranteed bounded switchover time, while making efficient use of the protection resources. The switchover time for the proposed algorithm is not fixed, but it gives the network administrator greater flexibility, according to the requirements from the MPLS multicast session as well as the availability of the network resources. An easy-to-use network topology builder and a simulator were implemented for the approach. Simulation results demonstrate that the proposed backup path approach with bandwidth optimization significantly reduces the cost of protection.