The HIP protocol for hierarchical multicast routing

This paper presents a new, flexible approach to inter-domain multicast routing. The HIP protocol introduces the idea of “virtual routers” as a method of organizing the control of an entire domain so as to appear as a single router on a higherlevel shared tree. HIP then routes between domains using the Ordered Core Based Tree (OCBT) protocol, and allows recursive application of virtual routers to create a multileveled hierarchy while providing efficient methods of distributing the location of the center point for the tree. The advantages of this approach include improved robustness, the ability to route between heterogeneous domains, and a significant reduction in the amount of bandwidth consumed in control traffic and in the amount of state stored at each router over existing hierarchical multicast protocols.