Receiver-initiated group membership protocol (RGMP): a new group management protocol for IP multicasting

This paper proposes a new group management protocol called Received-initiated Group Membership Protocol (RGMP) for IP multicasting. The dominant group management protocol on the Internet to date is the Internet Group Management Protocol (IGMP). Unlike IGMP based on a query/reply model, an RGMP host actively takes responsibility to refresh group membership on the neighboring multicast routers. Each RGMP host maintains a "refresh" timer per group. The refresh timer is reset once the suppression rule holds true for a received report message, where the report may be a join, departure, state change, or refresh message. The RGMP refresh timer is adjusted in a way to be adaptive and self-synchronized. This receiver-initiated, self-synchronized approach makes the RGMP suppression mechanism superior to that of IGMP v1/v2, because the latter can be applied only to periodical refresh messages. As a result, RGMP protocol overhead is significantly reduced over a wide variety of service scenarios compared to IGMP v3. In addition to the reduced protocol overhead, RGMP is robust, scalable and adaptive to serve as a group management protocol.