GDCoS: A Group Dedicated Class of Service for QoS Multicast Provisioning in ISP Communication Networks

Offering new multicast services supporting quality of service becomes essential for an Internet service provider at the worldwide level. The "IP multicast" technology is stable, but scalability of "quality of service multicast" is further from being solved, since scalability problems appear with the increasing number of concurrently active multicast groups. In this paper, we propose a framework that offers quality of service enabled multicast. We start with discussing the drawbacks of quality of service policies that are currently adopted by service providers, and point out their real needs from a multicast view point. In our approach, a service provider will propose an independent class of service dedicated to multicast applications. We describe the properties of this "dedicated class of service", and associate "admission control" mechanisms. We discuss the advantages of our approach, based on multicast extensions and adaptations of Diffserv model. Implementation issues are also presented in an MPLS environment. We conclude, through a case study, that it is possible to dedicate a class of service for multicast traffic.