Source Controlled Multicasting
Nokia Research Center
Nokia Research Center
University of Bonn
Traditionally, multicast trees in the Internet are built bottom-up. The construction of multicast trees depends on the multicast receivers's ability to inform their next hop multicast routers about their multicast group memberships. There are cases, in which the traditional host-driven way of building the multicast trees is insufficient. To point out one, consider an access network with unidirectional links. In a mobile environment, this requires that the receiving interface of a mobile node must also have the capabilities to send out MLD or IGMP responses. This is not possible for broadcast networks (e.g DVB-T and DAB), that provide high downstream data rates, but no uplink connectivity. This document presents Source Controlled Multicast as a proposal solution to overcome the problems with unidirectional links. It presents a way to for source to control the multicast tree joining process on behalf of mobile nodes behind unidirectional links.