A Survey and Performance Evaluation of Scalable Tree-based Application Layer Multicast Protocols

Application layer multicast (ALM) enables rapid deployment of multicast applications in the Internet. In ALM, application hosts organise themselves into an overlay topology on top of the underlying unicast network. Application data is multicast over the overlay network. In general, ALM protocols can be classified as either tree-first or mesh-first approach. In this paper, we provide a survey and simulation study for the class of tree-first ALM protocols. We investigate the efficiency of HMTP, TBCP, NICE and several variants of transformation-based protocols in terms of tree cost and delay optimisation. To the best of our knowledge, this paper provides the first head-to-head comparison of various tree-first protocols in a single simulation environment. Results show that depth-first searching technique in HMTP can achieve the lowest cost trees. On the other hand, a transformation-based technique that involves only local region nodes is able to construct low latency trees. In addition, we propose an enhancement to TBCP to improve its performance in producing low delay trees.