Resource partitioning for real-time communication

For real-time communication services to achieve widespread usage, it is important that network managers be allowed to control the services effectively. An important management capability concerns resource partitioning. Resource partitioning is useful for a number of applications, including the creation of virtual private subnetworks and of mechanisms for advance reservation of real-time network services, fast establishment of real-time connections, and mobile computing with real-time communication. In previous work, the authors presented a scheme for resource partitioning in a guaranteed performance networking environment with EDD-based packet scheduling disciplines. The present paper gives the results of research in resource partitioning, with admission control tests for resource partitioned servers for four representative scheduling disciplines, FIFO, WFQ, RCSP and EDD. The simulations confirm the intuition that resource fragmentation losses due to resource partitioning are small and that resource partitioning reduces the admission control computation overhead. An interesting result from the simulation experiments is that, under circumstances that arise naturally in multi-party communication scenarios, resource partitioning results in higher overall connection acceptance rate. The authors also present experiences with implementing resource partitioning in the second generation of Tenet real-time protocols; this implementation, with resource partitioned servers, runs on multiple platforms, including Sun workstations under SunOS, DEC workstations under Ultrix, and PCs under BSDI Unix