Programmable group communication services over IP multicast

Advances in high speed routing and switching devices in have made it possible to facilitate both new network services such as group communication, and to increase the level of router programmability. Programmability is considered as a feature not only allowing to better meet applications requirements (user viewpoint) but also to optimise network resources (provider viewpoint). We show how multicast-one of the mechanisms which allows providers to save network resources-could be used to design a new service (group communication) and to become programmable. Our approach is to concentrate on a protocol co-design, when several protocols which have to interoperate in order to achieve a common goal are sharing the same resources (mainly state information) dispersed over the network. By this we achieve better scaling features for higher level services supported by the protocols under co-design. The main advantage of our proposal is that new services introduced could be deployed incrementally.