Abstract
One of the most critical tasks for group communications lies in the establishment of multicast trees on the network. The famous two kinds of multicast trees are the shortest path-based trees and the Steiner-based trees. The former is suitable for those applications (such as video conferences) which wish to have a less propagation delay between the source (chairman site) to each of the receivers (member sites). The latter is well-suited for those ones (such as VoD services) which tend to consume the network resources (bandwidth) as less as possible. So far the routers have to implement separate routing protocols in order to support the construction of different kinds of multicast trees. This paper proposes a programmable distributed multicast routing protocol (PDMRP) for the routers so that different multicast trees can be established easily by only tuning a cost parameter.