Quality Of Service Support For Protocol Processing Within Endsystems

We describe a framework for providing quality-of-service (QoS) guarantees within the endsystem for networked multimedia applications. There are four components in this framework namely---QoS specification, QoS mapping, QoS enforcement, and protocol implementation. QoS specifications are at a high level, and use a small number of parameters to allow applications greater ease in specifying their requirements. Based on the QoS specifications, QoS mapping operations derive resource requirements for each end-to-end session of the application. Important resources considered are the cpu and the network connection. The third component of the framework is QoS enforcement. Enforcement is mainly concerned with providing real-time processing guarantees for protocol code during data transfer. We have implemented a real-time upcall (rtu) facility which is an enhancement to the well known upcall mechanism for structuring protocols. rtus are scheduled using a policy called rate monotonic with delayed..