Application-layer multicast with Delaunay triangulations

Recently, application-layer multicast has emerged as an attempt to support group applications without the need for a network-layer multicast protocol, such as IP multicast. In application-layer multicast, applications arrange themselves as a logical overlay network and transfer data within the overlay network. In this paper, Delaunay triangulations are investigated as an overlay network topology for application-layer multicast. An advantage of Delaunay triangulations is that each application can locally derive next-hop routing information without the need for a routing protocol in the overlay. A disadvantage of a Delaunay triangulation as an overlay topology is that the mapping of the overlay to the network-layer infrastructure may be suboptimal. It is shown that this disadvantage can be partially addressed with a hierarchical organization of Delaunay triangulations. Using network topology generators, the Delaunay triangulation is compared to other proposed overlay topologies for application-layer multicast.