Showing papers by "Jon Crowcroft published in 1993"

Core based trees (CBT)

Abstract: One of the central problems in one-to-many wide-area communications is forming the delivery tree - the collection of nodes and links that a multicast packet traverses. Significant problems remain to be solved in the area of multicast tree formation, the problem of scaling being paramount among these.In this paper we show how the current IP multicast architecture scales poorly (by scale poorly, we mean consume too much memory, bandwidth, or too many processing resources), and subsequently present a multicast protocol based on a new scalable architecture that is low-cost, relatively simple, and efficient. We also show how this architecture is decoupled from (though dependent on) unicast routing, and is therefore easy to install in an internet that comprises multiple heterogeneous unicast routing algorithms.

Integrating security in inter-domain routing protocols

Abstract: Network routing protocols work in a vulnerable environment. Unless protected by appropriate security measures, their operation can be easily subverted by intruders capable of modifying, deleting or adding false information in routing updates. This paper first analyses threats to the secure operation of inter-domain routing protocols, and then proposes various counter measures to make these protocols secure against external threats.

Analysis of burstiness and jitter in real-time communications

Abstract: This paper examines burstiness and jitter in real-time communications. In this paper, we make so assumptions about the arrival patterns of the incoming traffic but characterize the traffic with two parameters. We assume that the synchronization process is adaptive, so that the traffic stream can be divided into smaller synchronization units. The jitter is defined with the delay experienced by the first packet in a synchronization unit as the target delay. We present the results on the relationship between burstiness and jitter, and on the upper bounds of burstiness and jitter.

Some multimedia traffic characterisation and measurement results

Abstract: The authors discuss traffic characterisation and measurements made of experimental multimedia (including audio and video) traffic on the CAR and PREPARE experimental networks, and the IP pilot service on the UK JANET network. They describe the PREPARE experimental architecture and the proposed SuperJANET architecture. They summarise the characteristics of the various media and some of the architectural issues concerning multimedia conferencing. They present detailed results for measurements of shared files, shared windows, audio and video on the current JANET II network. Finally, they draw some conclusions about the future of multimedia services. >

A Unified Framework for Multicast Forwarding

Abstract: This paper examines the issues of implementation and integration in multicast. A framework for multicast forwarding is presented, which separates multicast forwarding from any associated protocols that may affect the forwarding decisions, such as multicast routing, resource management and host membership protocols. This framework allows seamless integration of various associated protocols and provides a unified interface for new development.

Analysis of burstiness and jitter in multimedia communications

Abstract: Examines burstiness and jitter in multimedia communications. The authors assume that the synchronization process is adaptive and the traffic stream can be divided into smaller synchronization units. They model the traffic in a synchronization unit with two parameters, and define jitter with the delay experienced by the first packet in a synchronization unit as the target delay. They then obtain results on the relationship between burstiness and jitter, and on the upper bounds of burstiness and jitter. >

Scalability analysis of inter-domain routing protocols

Abstract: With the rapid growth in internetwork connectivity, it is becoming increasingly important to contain the overheads associated with inter-domain routing protocols. This paper analyses and compares storage, route computation and communication overheads of existing protocols for inter-domain routing.