p-cycle based multicast protection — A new ILP formulation

Fast development of the Internet including increasing number of various streaming services, e.g., IPTV, gaming, distance learning, triggers the need to deploy robust methods to protect critical streaming sessions. Since the most effective way to provide streaming services in computer networks is multicasting, in this paper we focus on the problem multicast session protection. We propose to use the p-cycles approach to provide 100% protection against a single link failure. The key contribution of this paper is a new ILP (Integer Linear Programming) model for joint optimisation of working and spare capacity for link failure recovery problem in multicast flow protected by p-cycles proposed in [1]. The main idea of our approach is to model multicast sessions using predefined candidate trees, i.e., during the optimisation, one among several multicast candidate trees is chosen to realise each session. According to extensive numerical experiments, our new ILP model provides results very close comparing the previous ILP formulation (in some case even less than 3% worse), but the execution time is significantly lower.