Canopy: Publish/Subscribe with Upgraph Combination

In this paper, we present an outline of a new system called Canopy that supports publish/subscribe over the Internet by using upgraph information. In order to be able to derive pub/sub multicast structures for subscribers and publishers, a content distribution system, called rendezvous system, needs to know about packet replication points and policy-compliant paths. This information can be given to the rendezvous system by the subscribers and publishers by sending their upgraphs to pertinent rendezvous entities. The upgraphs contain all the possible paths from a given node to the tier-1 core networks. The upgraphs can then be combined to determine the subset or subspace of network topology that is relevant for the distribution of the information. We consider issues such a upgraph representation,peer-to-peer links between autonomous domains, multi-path operation, and applications of the technique.