Applying p-cycle protection for a reliable IPTV service in IP-over-DWDM networks

International audienceToday, television over Internet protocol (IPTV) has become very popular and service providers must deal with the rapid growth in the number of IPTV customers. Service providers must ensure the reliability of IPTV to satisfy customers' needs, as a network failure could disrupt an IPTV transmission. Survivable multicast routing is important for providing a reliable IPTV service. Generally, most carriers route multicast traffic using the protocol-independent multicast source-specific mode (PIM-SSM) based on the routing information provided by the interior gateway protocol (IGP). Restoration using the IGP reconfiguration is slow and typically takes from 10 to 60 seconds. To ensure a fast restoration, we consider node and link failure recovery in the Dense Wavelength Division Multiplexing (DWDM) optical layer. The backup path is provided in this layer. Thus, the multicast tree does not change at the IP layer (the logical links do not change) and the restoration time is faster (typically of the order of 50 to 80 ms). In this paper, we apply p-cycles in IP-over-DWDM networks to provide a robust IPTV service. In addition, we propose a novel concept for node protection using p-cycles to achieve more efficient resource utilization. We also propose a new algorithm, the node and link protecting candidate p-cycle based algorithm (NPCC). This algorithm integrates our new concept for node protection. Extensive simulations show that it outperforms the existing approaches in terms of blocking probability, resource utilization efficiency and computation time rapidity