Analytical study of reliable multicast for host mobility in IP networks

This paper studies analytically the performance of reliable multicasting for host mobility in IP networks. In particular, we examine two schemes: global token rotating and local recovery with tunneling. Both schemes support reliable multicast for mobile hosts at the expense of extra buffer spaces in mobility agents. The token rotating mechanism uses a rotating token which reports global packet reception status for all the agents in the system to cope with host mobility. An agent cannot remove a packet out of the buffer unless all the mobile hosts in the global system have correctly received the packet. The local recovery with tunneling approach, on the other hand, relieves this global waiting constraint from each agent. It requires each mobile to be registered with one agent, but changeable to a different agent upon handoff. The packets not repairable by new agents are then tunneled from previous agents. Each agent cannot remove a packet unless all the registered hosts under its service have correctly received the packet. We model the buffer requirements of both protocols as an M/G/∞ queuing system, from which we can further derive service latency and system throughput. We have also conducted simulations to verify the derived analytical model. The results show that the local recovery with tunneling mechanism has much smaller buffer size, higher throughput, and lower service latency, as compared to the token rotating mechanism