ICRA: Incremental Cycle Reduction Algorithm for optimizing multi-constrained multicast routing

In future Internet, multimedia applications will be strongly present. When a group of users is concerned by the same traffic flow, the multicast communication can decrease considerably the network bandwidth utilization. The major part of this kind of multicast communication needs quality of service (QoS) specification. Often, the QoS is given as a set of QoS criteria and the computation of feasible or optimal routes corresponds to a multi-constrained optimization. Finding the multicast graph respecting the defined QoS requirements and minimizing network resources is a NPcomplete optimization task. Exhaustive search algorithms are not supported in real networks. Greedy algorithms was proposed to find good multicast sub-graphs. In this paper, we propose a greedy algorithm ICRA to improve themulti-constrainedmulticast sub-graph computed by the already proposed algorithm Mamcra. We show through different examples that ICRA tackles all cases that Mamcra fails to deal with.