The Internet has been a startling and dramatic success. However, multimedia applications, with their novel traffic characteristics and service requirements, pose an interesting challenge to the technical foundations of the Internet. In this paper we address some of the fundamental architectural design issues facing the future Internet. In particular, we discuss whether the Internet should adopt a new service model, how this service model should be invoked, and whether this service model should include admission control. These architectural issues are discussed in a nonrigorous manner, through the use of a utility function formulation and some simple models. While we do advocate some design choices over others, the main purpose here is to provide a framework for discussing the various architectural alternatives.

Integrated Services Packet Networks (ISPN) are designed to integrate the network service requirements of a wide variety of computer-based applications. Some of these services are delivered primarily through the packet scheduling algorithms used in the network switches. This paper addresses two questions related to these scheduling algorithms. The first question is: what scheduling services should an ISPN offer? In answer, we propose a scheduling service model for ISPN's which is based on our projections about future application and institutional service requirements. Our service model includes both a delay-related component designed to meet the ergonomic requirements of individual applications, and also a hierarchical link-sharing component designed to meet the economic needs of resource sharing between different entities. The second question we address is: what implications does this service model have for the packet scheduling algorithms? We answer this question by construc...