Scalable Support for Source Specific Multicast in Differentiated Services Networks

In this paper we propose a scalable framework for providing differentiated QoS multicast channels for end users with heterogeneous requirements based on the Source Specific Multicast (SSM) model, which we name QoS Source Specific Multicast (QSSM). By encoding each QoS service class into a multicast group address and by maintaining the corresponding mapping table at the edge of each DiffServ domain, the proposed QSSM architecture embraces per-group QoS statelessness at core routers, which is a vital requirement of the DiffServ paradigm. We construct independent trees for each class of service, i.e. QoS-specific trees, in order to reduce routing complexity and avoid QoS fairness issues among different classes.