Admission control and quality adaptation in the distributed multimedia server system (DMSS)

Transmission of the real-time components, such as video and voice of multimedia streams over internets requires pre-allocation of network bandwidth from source to destination, as well as CPU cycles, I/O bandwidth, etc. in the server and in the client providing multimedia services. This paper presents a distributed version of the Utility Model for admission control and Quality of Service (QoS) adaptation of a multi server multimedia service provider. We propose a broker for managing the resources of the servers. This version of the Utility Model is quasi-distributed, meaning that computations for resource allocation are done at a single site (the broker), but the resources considered are distributed over multiple servers. This paper presents the architecture of the broker and the algorithm used by the broker to select the sessions, so that the QoS requirements are met while revenue is maximized. The QoS adaptation policy used to achieve fault tolerance during server failure is described.