A scheme for real-time channel establishment in wide-area networks

Abstract

Multimedia communication involving digital audio and/or digital video has rather strict delay requirements. A real-time channel is defined in this paper as a simplex connection between a source and a destination characterized by parameters representing the performance requirements of the client. A real-time service is capable of creating real-time channels on demand and guaranteeing their performance. These guarantees often take the form of lower bounds on the bandwidth allocated to a channel and upper hounds on the delays to he experienced by a packet on the channel. In this paper, we study the feasibility of providing real-time services on a packet-switched store-and-forward wide-area network with general topology. We describe a scheme for the establishment of channels with deterministic or statistical delay hounds, and present the results of the simulation experiments we ran to evaluate it. The results are encouraging: our approach satisfies the guarantees even in worst case situations, uses the network's resources to a fair extent, and efficiently handles channels with a variety of offered load and burstiness characteristics. Also, the packet transmission overhead is quite low, and the channel establishment overhead is small enough to be acceptable in most practical cases.

A Distributed Route-Selection Scheme for Establishing Real-Time Channels

“…The concept of "real-time channel" proposed by Ferrari and Verma [4] is one of the most notable solutions to the problem of meeting messagefpacket 1 delivery deadlines in wide-area point-to-point networks. A real-time channel is a unidirectional virtual circuit which, once established, is guaranteed to meet user-specified performance requirements as long as the user does not violate his a priori specified traffic-generation characteristics [4].…”

“…phase is of prime importance to the realization of a real-time channel, and during this phase, the system has to select a route between the source and destination of the channel along which sufficient resources can be reserved to meet the user-specified delay and buffer requirements. Although several channel-establishment schemes have been proposed in the literature [2,4,5,7], very few oft hem have addressed explicitly the issue of selecting a route between the source and destination of a channel, despite its importance to the channelestablishment phase.…”

An Admission Control Algorithm for Scheduling Mixed Traffic in Ubiquitous Environment

“…Real-time packet schedulers based on Earliest Deadline First (EDF) policy have been studied to support end-to-end bounded delay for real-time traffic [10,7,4,5,1]. In [10], a general necessary and sufficient schedulability (deadline guarantee) condition of EDF was obtained for flows with traffic regulation assumption.…”

Equus: a QOS manager for distributed applications

“…Typical QOS parameters describe throughput , delay, jitter and loss rates. Using this information, Ferrari (1990) has shown how to negotiate for network resources between the source and sink of data streams. While much of this work is related to ATM, there are also efforts to accommodate QOS in the Internet, see Mitzel (1994).…”