Date Added: Oct 2009
Recent efforts are made to construct a globally accessible group communication service by a simultaneous use of network and application layer multicast. Such hybrid approaches provide native multicast to group members wherever available, but relocate data distribution and duplication from the network to applications or gateways if needed. Such services require an abstract programming interface to allow for a transparent use by applications. The contributions of this paper are twofold. First, the authors explore the problem space of designing a protocol stack for hybrid group communication that covers structured P2P networks. Second, they propose a transparent API that encapsulates a middleware abstraction layer for implementing hybrid multicast, and allows for overlay-underlay agnostic programming.