Speccast

We describe a new network service called speccast. Speccast offers a generalized addressing and routing abstraction on which a rich variety of semantic services can be built, and, as such, provides a vehicle for studying the relationships among routing, addressing and topology. Unlike overlay-based systems, we study a more basic problem, in which the topology of the network is given, and there is not necessarily any pre-existing underlying network service. In the speccast model, each packet carries a destination predicate and the network´s job is to deliver the packet to all nodes satisfying that predicate. After showing how this generalized routing service subsumes other services both traditional (unicast, multicast) and emerging (publish-subscribe), we present a layered solution for a specific class of simple predicates. We examine the tradeoffs in various forms of our approach, and compare it to existing solutions for unicast and multicast. Studies using transit-stub graphs show that our generic service performs comparably to existing solutions for traditional services, while also effectively supporting new and emerging services.