Design, Implementation, and Experiences of the OMEGA End-Point Architecture

The OMEGA architecture provides end-to-end quality-of-service (QoS) guarantees for distributed applications. QoS parameters are translated between application and network requirements by the QoS broker, thus integrating media and network QoS management into a single entity. Admission control uses a schedulability test derived from application requirements. A novel task priority and precedence-based scheme is used to represent complex application requirements and ensure correct feasible schedules. A prototype of OMEGA has been implemented using workstations connected by a 155 Mb/s dedicated ATM local-area network (LAN). To simplify implementation, we assumed networked multimedia application with periodic media streams, specifically a master/slave telerobotics application. This application employs media with highly diverse QoS requirements (e.g., interarrival times, loss rate, and bandwidth) and therefore provides a good platform for testing how closely one can achieve QoS guarantees with workstation hosts and cell-switching. Experience with this implementation has helped to identify new challenges to extending these techniques to a larger domain of applications and systems, and suggests promising new research questions.