Without an efficient and fast failure recovery mechanism, capricious network failures can lead to severe disruption to optical multicast sessions and calamitous loss to network operators, Internet service providers, and end customers. Most research on optical multicast media traffic protection considers link and intermediate node failures but not source node failures. However, source failure recovery is more important than failure recovery of any other node or link on a multicast tree, especially for Internet Protocol television applications, which have real-time constraints. Without a source failure recovery mechanism, if the source node fails, all multicast sessions originating from the source are terminated. Simply adding the source redundancy cannot guarantee reliable optical multicast transmission in the case of catastrophic source failure. Thus, the development of efficient protection algorithms equipped with source redundancy, which can handle source failure recovery is critical to the success of optical multicast media. In this paper, we extend the flow p-cycle-based protection approach to source failure recovery on top of combined node and link failure recovery. Simulation results show that the additional capacity required for source failure recovery is comparable to the additional capacity required for (intermediate) node failure recovery, on top of link failure recovery. Both are less than 14%, with reference to link failure recovery. Results also show that the flow p-cycle-based dual-source multicast protection approach provides significant capacity saving compared with the modified optimal-path-pair-based dual-source approach.
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