Structuring Communication Software for Quality-of-Service Guarantees

In this paper, we propose architectural mechanisms for structuring host communication software to provide QoS guarantees. In particular, we present and evaluate a QoS-sensitive communication subsystem architecture for end hosts that provides real-time communication support for generic network hardware. This architecture provides services for managing communication resources for guaranteed-QoS (real-time) connections, such as admission control, traffic enforcement, buffer management, and CPU & link scheduling. The design of the architecture is based on three key goals: maintenance of QoS-guarantees on a perconnection basis, overload protection between established connections, and fairness in delivered performance to besteffort traffic. Using this architecture we implement real-time channels, a paradigm for real-time communication services in packet-switched networks. We evaluate the implementation to demonstrate the efficacy with which the architecture maintains QoS guarantees while ad..