A simple hierarchical approach to intra/inter domain multicasting

In this paper, a simple hierarchical approach to inter/intra domain multicasting is introduced. The proposed Hierarchical Tree Multicast Protocol (HTMP) supports sender initiated multicasting, i.e., requires by an application starting a multicast session to provide an initial list of potential receivers. Based on this information, HTMP utilizes the unicast routing information which is currently available in the Internet routers and builds a hierarchical shared tree architecture which consists of separate intra-domain core based trees interconnected by a core based inter-domain tree that may span the entire Internet. Although HTMP requires an initial group of potential receivers, it allows for new hosts to join in supporting three modes of session participation: a) a restricted mode which allows access only to a specified list of group members, b) a semi-restricted mode which allows new members to join in but only after authorization from the session manager, c) an open mode which does not require any authorization. HTMP supports a distribution (one-to-many) mode of multicasting, in which the hierarchical tree is transformed into a source based tree with core the session initiator, as well as an interactive mode (many-to-many) of multicasting. Finally, HTMP provides a receiver oriented resource reservation mechanism which allows for heterogeneity of traffic streams.