Asynchronous Transfer Mode

About: Asynchronous Transfer Mode is a research topic. Over the lifetime, 11026 publications have been published within this topic receiving 173437 citations. The topic is also known as: ATM.

Charging and rate control for elastic traffic

Abstract: This paper addresses the issues of charging, rate control and routing for a communication network carrying elastic traffic, such as an ATM network offering an available bit rate service. A model is described from which max-min fairness of rates emerges as a limiting special case; more generally, the charges users are prepared to pay influence their allocated rates. In the preferred version of the model, a user chooses the charge per unit time that the user will pay; thereafter the user's rate is determined by the network according to a proportional fairness criterion applied to the rate per unit charge. A system optimum is achieved when users' choices of charges and the network's choice of allocated rates are in equilibrium.

The iSLIP scheduling algorithm for input-queued switches

Abstract: An increasing number of high performance internetworking protocol routers, LAN and asynchronous transfer mode (ATM) switches use a switched backplane based on a crossbar switch. Most often, these systems use input queues to hold packets waiting to traverse the switching fabric. It is well known that if simple first in first out (FIFO) input queues are used to hold packets then, even under benign conditions, head-of-line (HOL) blocking limits the achievable bandwidth to approximately 58.6% of the maximum. HOL blocking can be overcome by the use of virtual output queueing, which is described in this paper. A scheduling algorithm is used to configure the crossbar switch, deciding the order in which packets will be served. Previous results have shown that with a suitable scheduling algorithm, 100% throughput can be achieved. In this paper, we present a scheduling algorithm called iSLIP. An iterative, round-robin algorithm, iSLIP can achieve 100% throughput for uniform traffic, yet is simple to implement in hardware. Iterative and noniterative versions of the algorithms are presented, along with modified versions for prioritized traffic. Simulation results are presented to indicate the performance of iSLIP under benign and bursty traffic conditions. Prototype and commercial implementations of iSLIP exist in systems with aggregate bandwidths ranging from 50 to 500 Gb/s. When the traffic is nonuniform, iSLIP quickly adapts to a fair scheduling policy that is guaranteed never to starve an input queue. Finally, we describe the implementation complexity of iSLIP. Based on a two-dimensional (2-D) array of priority encoders, single-chip schedulers have been built supporting up to 32 ports, and making approximately 100 million scheduling decisions per second.

New directions in communications (or which way to the information age

Abstract: hat a difference 25 years makes! When this article was written the telecommunications industry was still a heavily regulated, non-competitive but highly integrated place; the Internet was the private preserve of congnoscenti at a handful of research universities; integrated circuits with a feature size of 2 micron were state-of-the-art; and the room-sized minicomputers of the day could send and receive maybe a thousand packets per second, on a good day. This article articulated an observation that was gaining recognition throughout the early 1980s: first, that the fragmentation of the communications infrastructure into several distinct application-specific networks was wasteful and unnecessary; and second, that by combining concepts from packet switching with the implementation practices of circuit switching (highly parallel, hardware switching systems), one could develop systems with unprecedented flexibility and the performance levels and reliability needed to support large-scale, ubiquitous deployment. By the mid to late 1980s, these ideas were being pursued most vigorously in the development of ATM standards and technology, which was widely expected to play a leading role in the next generation of the public telecommunications infrastructure. The article outlined some of the key elements of such an integrated network technology, capable of supporting voice, data, and video communication and having the flexibility to accommodate new services as the need arose. Integrated switching architectures, generalized connection signaling protocols, quality-of-service, multicast switching, and routing were all identified as key challenges to be addressed. Subsequent years have seen tremendous progress on all these fronts in both the ATM context and in the now all-important Internet context. The changes in packet switching technology over the last two decades are particularly striking. While advanced switching architectures were first developed in the ATM context, these concepts have been applied with striking success in Ethernet switches and IP routers in recent years. Emerging IP router products with aggregate capacities exceeding a terabit per second are becoming available now, and gigabit Ethernet switches are available for just hundreds of dollars per port. Progress on other fronts has been more disappointing. While practical and effective solutions for connection signaling, quality-of-service, congestion control, and multicast have been developed and demonstrated, there has been little progress toward widespread commercial deployment. We still operate separate networks for voice, data, and video, and while the Internet promises to play a growing role in voice and video communication, it cannot achieve that promise without major technical improvements. Fortunately, the potential value of such improvements is becoming more and more clear, as the Internet’s role in our evolving information society continues to develop. While challenges remain, there seems little doubt that the necessary changes can and will be made, and that the full realization of the vision outlined in this article 25 years ago is now within our grasp. Jonathan S. Turner

IPACT a dynamic protocol for an Ethernet PON (EPON)

Abstract: We investigate design issues for access networks based on passive optical network technology. A PON based on polling, with data encapsulated in Ethernet frames, possesses many desirable qualities, such as dynamic bandwidth distribution, use of a single downstream and a single upstream wavelength, ability to provision a fractional wavelength capacity to each user, and ease of adding a new user. To support dynamic bandwidth distribution, we propose an interleaved polling algorithm called IPACT. We also suggest a scheme for in-band signaling that allows using a single wavelength for both downstream data and control message transmission. To obtain realistic simulation results, we generated synthetic traffic that exhibits the properties of self-similarity and long-range dependence. We then analyzed the network performance under varying offered loads.

Multiservice Loss Models for Broadband Telecommunication Networks

Abstract: Loss networks ensure that sufficient resources are available when a call arrives However, traditional loss network models for telephone networks cannot cope with today's heterogeneous demands, the central attribute of Asynchronous transfer Mode (ATM) networks This requires multiservice loss models This text presents mathematical tools for the analysis, optimization and design of multiservice loss networks These tools are relevant to modern broadband networks, including ATM networks Addressed are networks with both fixed and alternative routing, and with discrete and continuous bandwidth requirements Multiservice interconnection networks for switches and contiguous slot assignment for synchronous transfer mode are also presented