End-to-End QoS Guarantees: Lessons Learned from OMEGA

With audiovisual and other sensory information in distributed multimedia applications, end-to-end quality of service guarantees are a major acceptance factor for these applications. We designed and implemented an end-point architecture, called OMEGA, for provision of end-to-end QoS guarantees. This architecture relies on a distributed QoS management entity, called the QoS Broker, to translate, negotiate/renegotiate, and admit end-to-end QoS as a contract. It uses end-to-end real-time protocols for transport. We tested our architecture on a telerobotics application. This paper presents various lessons learned from implementation of the OMEGA architecture. Performance gures show that the design of OMEGA was correct; we can provide end-to-end QoS guarantees. However, the results also show that shortcomings of the implementation platform, its system software support, and our own implementation decisions, coupled with the inherent conservatism of resource reservations, severely limited the applications. Some of these lessons are obvious, some are connected directly to the speciic platform, but some are of a general nature, and need thorough consideration and new algorithms, QoS management and QoS system support schemes.