Optimal multicast routing with quality of service constraints

We consider the problem of optimal multicast routing with Quality of Service con-straints motivated by the requirements of interactive continuous media communica-tion, e.g., real-time teleconferencing. We concentrate on distributed algorithms for determining a tree over the network topology, rooted at the source and spanning th

Two Distributed Algorithms for Multicasting Multimedia Information

This paper addresses the problem of effective multicast tree construction for interactive audiovisual communication to several destinations. We believe that the effectiveness of a multicast tree for such applications is determined by two factors: (i) the end-to-end delay along the individual paths from source to each destination, and (ii) the cost of the multicast tree, for example, in terms of network bandwidth utilization. Note that while the cost of the tree should be minimized, it is sufficient simply to bound the delay. The problem of computing the optimal constrained multicast tree is NP-complete. We present two distributed algorithms that compute low cost trees with delay-bounded paths from the source to each destination. Keywords: Multicast, interactive multimedia, Steiner tree, distributed algorithm, constrained optimization. 1 Introduction Multicasting, the simultaneous transmission of data to multiple destinations, is now being viewed as a very important service in netwo..

The Multimedia Multicasting Problem

We present the problems associated with multicast communication for multimedia group applications, such as video-conferencing. In particular, when these applications have continuous media I/O components (e.g., audio and video) which must be communicated to a group of receivers, unique problems arise. Perhaps the most fundamental problem is whether feedback should be used in dynamic control; we argue against such reactive control mechanisms and in favor of more proactive mechanisms. We discuss a number of issues, including routing, resource reservation, error control, heterogeneity, and hierarchical coding. Keywords: broadcast, routing, interactive group communication, continuous media, communication network architectures. #################################### Joseph Pasquale may be contacted at [email protected], +1-619-534-2673, +1-619-534-7029 (FAX). George Polyzos may be contacted at [email protected], 1+619-534-3508, +1-619-534-7029 (FAX). Vachaspathi Kompella may be contacted at..

The Multimedia Multicasting Problem

We present the problems associated with multicast communication for multimedia group applications, such as video-conferencing. In particular, when these applications have continuous media I/O components (e.g., audio and video) which must be communicated to a group of receivers, unique problems arise. Perhaps the most fundamental problem is whether feedback should be used in dynamic control; we argue against such reactive control mechanisms and in favor of more proactive mechanisms. We discuss a number of issues, including routing, resource reservation, error control, heterogeneity, and hierarchical coding

Filter Propagation in Dissemination Trees:

We describe the concept of the relocatable continuous media filter. The novelty of these filters is how they can propagate over a dissemination tree in a network. We describe the filter propagation protocol to achieve this. Execution of filters inside a network allows the network to be viewed in a novel way, as a "processor" with its "instruction set" being the various types of available filters. Since filters generally modify the data rate of the continuous media stream, usually (but not necessarily) reducing it, filters allow the trading off of bandwidth and processing in a network

Network and Operating System Support for Multimedia Applications

This paper describes the general problems in providing system software support for multimedia applications. We specifically focus on applications which have digital continuous media (DCM) I/O components, and the type of support that must be provided by the network software and operating system. DCM applications have large bandwidth and low delay requirements. We discuss network software support to meet these requirements, such as resource reservation schemes based on parameterized requests for some level of quality of service. Most likely, DCM communications will be long-lived, which suggests that connections are the appropriate network construct for such communications. Regarding the operating system, we describe issues of real-time resource scheduling, synchronization of processes and temporally related DCM flows, shared memory, and the need for a modular, uniform I/O abstraction. Finally, we present design principles based on the concepts of moving processes to data and separating d..