Mobility support for the core-manager based scalable multicast routing

The core-manager based multicast routing (CMMR) architecture developed by the authors is a scalable multicast routing scheme in which the core-manager (CM) keeps tracking cores of each multicast delivery tree in order to maintain a brief image of the tree. Consequently, new members will almost always be directed to a nearby core to join the group tree so that tree cost is well confined. Further improvement on scalability is sought by using a hierarchical architecture, which requires the multicast addresses be administratively scoped in accordance with the hierarchy. Given such a hierarchical CMMR multicast autonomous region, the mobility support is treated in two different cases, namely non-transition mobility and scope-transition mobility. Different approaches to reconnecting a mobile multicast group member host to its group shared-tree after each moving into a new subnetwork are discussed in detail, and their performances in terms of reconnection latency are thoroughly evaluated by simulations