We introduce a novel passive network monitoring architecture which enables us to capture and integrate data from different levels of the protocol stack using a probe which can be placed at any arbitrary point in the network. We subject the data gathered to off-line analysis and show how, by modelling the dynamics of the protocols observed, we are able to extract information which would not be available using existing means. We show how the technique can be used to passively measure Web server response latency. Experiments are described which use artificially generated loads to validate the techniques used, and results obtained from the observation of real traffic are presented.

In the management of a modern LAN or campus network, two issues are of key importance, namely network performance and capacity planning. In this paper we report on results from an experimental programme which aims to quantify the performance that can be achieved with a real distributed application running over a range of different network technologies, including Ethernet, ATM, FDDI, and a 100 Mb/s packet-switched LAN. In particular we analyse the contribution of each of the various application and network components to the overall performance experienced by applications.

The concept of a service-specific control architecture (SSCA) in an ATM environment is presented. Here, a control architecture denotes the out-of-band control and management mechanisms operational in a network or virtual network (or part thereof). An SSCA can use knowledge about the applications it serves to make better use of network resources, and thus provide a more efficient service. Such a control architecture can be designed to provide only the subset of control functions required by the applications it serves, thereby greatly reducing its complexity. The switchlet mechanism, which allows more than one control architecture to be operational simultaneously within the same network, enables the use of service-specific control architectures. Implementation work is presented to illustrate the use of switchlets and SSCAs. This includes both an environment which uses switchlets to dynamically create virtual networks, and an SSCA used to provide video- and audioconferencing facilities in an ATM environment.

In the management of a modern LAN or campus network, two issues are of key importance, namely network performance and capacity planning. In this paper we report on results from an experimental programme which aims to quantify the performance that can be achieved with a real distributed application running over a range of different network technologies, including Ethernet, ATM, FDDI, and a 100 Mb/s packet-switched LAN. In particular we analyse the contribution of each of the various application and network components to the overall performance experienced by applications. This information will facilitate planning and management of new networks, and permit the identification of "hidden costs" which prevent currently deployed applications from fully exploiting high bandwidth networks.

Support for multimedia applications by general purpose computing platforms has been the subject of considerable research. Much of this work is based on an evolutionary strategy in which small changes to existing systems are made. The approach adopted is to start ab initio with no backward compatibility constraints. This leads to a novel structure for an operating system. The structure aims to decouple applications from one another and to provide multiplexing of all resources, not just the CPU, at a low level. The motivation for this structure, a design based on the structure, and its implementation on a number of hardware platforms is described.

We describe a case study which demonstrates that, by designing with formal verification in mind, a designer can simplify the verification task enormously without sacrificing other design considerations. In addition, the formal specification and verification process can highlight anomalies in a design, and suggest design changes that improve it. The design we considered was a switching fabric for an ATM network switch. It is a real, fabricated component of a working network.

In previous approaches to routing multicast connections in networks, the emphasis has been on the source transmitting to a fixed set of destinations (the multicast group). There are some applications where destinations will join and leave the multicast group. Under these conditions, computing an 'optimal' spanning tree after each modification may not be the best way to proceed. An alternative is to make modest alterations to an existing spanning tree to derive a new one. An extreme, though nonoptimal, variation of this is to use minimal cost source to destination routing for each destination, effectively ignoring the existing multicast tree. The authors examine just how nonoptimal these trees are in random general topology networks and conclude that they are worse by only a small factor. The factor is reduced still further if a hierarchy is imposed on the random network to give a more realistic model.>

The authors evaluate the performance of the input traffic control used to enforce input traffic to conform to the traffic parameters negotiated during connection establishment in broadband asynchronous transfer mode (ATM) networks. They provide an exact analysis of the input traffic control mechanism for both Poisson traffic and bursty traffic. The model yields the steady-state system state probability distribution, the probability that an arriving cell is blocked, and the average cell length and waiting time. In addition, a characterization of the inter-departure process is given, along with the evaluation of variation of the inter-departure time. Extensive numerical results are presented.>

Article Free Access Share on Fairisle: an ATM network for the local area Authors: Ian Leslie University of Cambridge, Computer Laboratory University of Cambridge, Computer LaboratoryView Profile , Derek McAuley University of Cambridge, Computer Laboratory University of Cambridge, Computer LaboratoryView Profile Authors Info & Claims SIGCOMM '91: Proceedings of the conference on Communications architecture & protocolsAugust 1991 https://doi.org/10.1145/115992.116022Published:01 August 1991Publication History 56citation473DownloadsMetricsTotal Citations56Total Downloads473Last 12 Months68Last 6 weeks11 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

One of the principle advantages of Asynchronous Transfer Mode (ATM) access is that variable rate streams can be supported efficiently. In order to preserve this efficiency when using ATM on an underlying circuit switched network, such as primary rate ISDN, flexible control of the underlying circuit bandwidth must be provided. This paper discusses techniques used to provide dynamic management of variable rate circuits to support ATM access. Models are presented for some of these control schemes and their performance is studied through a combination of simulation and analysis. Techniques implemented for an experimental network providing ATM access on primary rate ISDN are presented.

Asynchronous Transfer Mode (ATM) has been advocated as the basis of multiservice telecommunications in the next century. However, the public telecommunication technology of the 1990's will be ISDN, which presents a circuit switched subscriber interface. An obvious approach to building a wide area ATM network is to build it on top of primary rate ISDN. In this paper we describe the lessons learned through the design and deployment of such a network.