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...

New network applications which involve transmission of continuous media data, such as audio and video conferencing, introduce immense challenges for the design of packet-switching internetworks. Existing flow and congestion control mechanisms have been shown to be ineffective for supporting the real-time requirements of continuous media data transfers. We propose a novel bandwidth regulation mechanism which improves the ability of the network to cope with multiple real-time and non real-time traffic classes. The mechanism achieves regulation of link bandwidth at two levels. At one level, bandwidth is dynamically regulated between different traffic classes. We introduce the concept of inter-class regulation which enforces that the bandwidth left unused by some traffic classes is assigned equally to traffic classes with high bandwidth demands. At the second level, bandwidth regulation is enforced on packet flows from the same class. Each end-to-end packet flow from the same class has ide...

. Distributed audio and video applications need to adapt to fluctuations in delivered quality of service (QoS). By trading off temporal and spatial quality to available bandwidth, or manipulating the playout time of continuous media in response to variation in delay, audio and video flows can be made to adapt to fluctuating QoS with minimal perceptual distortion. In this paper, we extend our previous work on a QoS Architecture (QoS-A) by populating the QoS management planes of our architecture with a framework for the control and management of multilayer coded flows operating in heterogeneous multimedia networking environments. Two key techniques are proposed: i) an end-to-end rate-shaping scheme which adapts the rate of MPEG-coded flows to the available network resources while minimizing the distortion observed at the receiver; and ii) an adaptive network service, which offers "hard" guarantees to the base layer of multilayer coded flows and "fairness" guarantees to the enhancement la...

This paper discusses the RCO concept in the abstract. A companion paper, "Resource Coordination Objects: Service Design," describes a strawman implementation and discusses open issues in the design. DRAFT 2 The following sections describe why we feel an RCO-like protocol is needed, list the general goals we feel should govern the design of the mechanism, provide a strawman service specification, and outline the design of the RCO service. These sections are followed by a relatively complete example of how RCOs might be used to implement a higher-level protocol, some discussion on deployment-related issues, and a summary of the current status of our RCO work. 2 Motivation