Internet is evolving to be an integrated service platform for promising future global information infrastructure. New multimedia services, e.g., Video-on-Demand, are expected to be provided on this platform, in conjuction with the existing rich information exchange and sharing services on Internet, such as E-mail, WWW. The paper proposes a service system architecture for Video-on -Demand on Internet, named MINS (Multimedia Internet Navigation System), which is capable of both realtime audio/video transmission and realtime and VCR like plya-out. MINS is composed of 1) servers maintaining both audio/video program lists and contents, and 2) clients retrieving the programs and play-out them. The paper focuses on the communication architecture in MINS, e.g., flow control, realtime media synchronization control, and audio/video session control. The performance of the prototype MINS is also evaluated in the paper.

Over the last decade, the Internet has been extremely successful by distinguishing between overlaying applications and underlying networking technologies. This approach allows rapid and independent improvement in both networking and application technologies. The internetworking layer that divides applications and the network enables the Internet to function as a general and evolving infrastructures for data communications. The current Internet architecture offers only best-effort data delivery. However, recent emerging computer and networking technologies, demand the Internet guaranteed performance. In particular, audio and video applications have more rigid delay requirement than those applications which the current Internet supports. To offer guaranteed services in addition to best-effort services, both a new service model and a new architecture are necessary in the Internet architecture. The paper surveys researches and experiments conducted in the Internet community to accommodate a wide variety of qualities of services.