QoS-based MPLS multicast tree selection algorithms

Identifying a multicast label-switched-path (LSP) tree that satisfy a set of traffic-oriented and resource-oriented QoS constraints such as cost, reliability, bandwidth, jitter, and delay, has become an important research issue in the area of multicast routing in MPLS networks. In general, multi-constrained multicast tree-selection is an NP-complete problem. In this survey, QoS-based multicast tree-selection algorithms from the perspective of optimization techniques are evaluated. The existing algorithms are classified into three dimensions: non-MPLS-/MPLS-based, single/multiple QoS constrained, and heuristic-/unicast-/artificial-intelligence optimization techniques. In addition to state-of-the-art review of existing solutions, this article highlights important characteristics of QoS-based MPLS multicast algorithms and discuss important issues that are worthy of investigation in future research activities.