High performance group communication services in ATM networks

Advanced applications, such as distributed multimedia applications, require efficient communication subsystems providing a variety of services. Existing communication systems face increasing difficulties in fulfilling these requirements. In particular, the efficient provision of reliable group communication services in ATM-Networks remains a major unresolved issue. This paper presents a novel framework for support of multipoint communication in ATM networks. Two adaptation layer protocols are presented that provide reliable multicast services. The first one, called RLMCP (Reliable Lightweight Multicast Protocol), is a simple and efficient adaptation layer protocol for the Service Specific Convergence Sublayer of AAL5. It uses a frame-based ARQ scheme and is suitable for virtual connections with low cell loss rates. The second one, called RMC-AAL (Reliable Multicast ATM Adaptation Layer), features cell-based ARQ and cell-based FEC. A new network element, called the Group Communication Server (GCS), is presented for implementing the adaptation layer protocols in network nodes. It allows for hierarchical multicast error control and support of heterogeneous scenarios. The framework permits to select the combination of error control mechanisms most suitable for the requirements of a specific communication scenario. The functionality of end systems and group communication servers is described, and a basic implementation architecture is presented. Based on this architecture, approximations for the processing delays are presented when the different error control schemes are applied. Finally, the influence of the different error control schemes onto the selection of an appropriate memory management strategy is investigated.