John S. Crawford

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This paper introduces a flexible new method of constructing hierarchical multicast structures suitable for supporting large-scale GRID applications. Hierarchical multicast trees are constructed by repeated application of clustering algorithms that partition the members of a large application community to form a layered hierarchy of clusters of users. The(More)
Conventional delivery mechanisms for many-to-many multicast services consider either a single shared tree or a source rooted trees approach. These two mechanisms complement each other in terms of performance and protocol complexity. In this paper, we describe a design that uses multiple shared trees that would provide a balance between these two extreme(More)
An increasing number of networking applications involve m ul-tiple participants and are therefore best supported by m ulticasting. Where a m ulticast application consumes high bandwidth, it is important to min-imise the eeect on the network by oering economical multicast routes. Many new applications made possible by n e t works based on ATM involve(More)
We study decentralised low delay degree-constrained overlay multicast tree construction for single source real-time applications. This optimisation problem is NP-hard even if computed centrally. We identify two problems in traditional distributed solutions, namely the greedy problem and delay-cost trade-off. By offering solutions to these problems, we(More)
— Application layer multicast (ALM) enables rapid deployment of multicast applications in the Internet. In ALM, application hosts organise themselves into an overlay topology on top of the underlying unicast network. Application data is multicast over the overlay network. In general, ALM protocols can be classified as either tree-first or mesh-first(More)
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