On the Maintenance of Low Cost Multicast Trees with Bandwidth Reservation

Emerging multimedia network technologies are bringing new challenges to protocols design, due to new QoS requirements. These requirements, when combined with traditional network functions, such as routing, render the design of such protocols more complex than ever before. Resource reservation is one of the novel features brought into the picture by multimedia applications. Another is the manyto-many nature of multicast connections. We have recently proposed a routing algorithm to build low cost multicast trees. In this paper, we study the maintenance of these multicast trees, in the face of multicast membership changes over time (join/leave). One of the key issues is the tradeo between the incremental upgrade at each join/leave request and the recomputation of the entire tree at each step. Simulation results are used to illustrate these trade o s. A signalling mechanism for the implementation of the incremental tree updating is also included. Technical Subject Areas: Broadband Switching Systems and ATM Networks, Multimedia and Broadband Services.