Distributed Management of Application Layer Multicast Trees for IPTV Services

Abstract

IP multicast is an eff cient mechanism to distribute IPTV content towards multiple users, but nowadays Internet Providers f lter out this kind of traff c, mainly due to security and accounting issues. In order to overcome this f ltering, the same idea of IP multicast can be implemented at the end user terminals, but implementing multicast trees at the application layer, also known as Application Layer Multicast (ALM). ALM has some drawbacks, mainly due to dynamic behavior of users, joining and leaving the trees. In order to minimize the impact of this behavior, this paper proposes a distributed management for ALM in IPTV, instead of a centralized one, where some nodes connected to a tree will be on charge of the management of that tree. Furthermore, all nodes are dynamically conf gured with the substitute of its parent node in order to accelerate the reconnection process. Results presented in this article show that this proposal provides fast reconstructions and low management load per node, while keeping a balanced tree topology.