Router level filtering for receiver interest delivery

Delivering data to on-line game participants requires the game data to be "customized " in real-time to each participant’s characteristics. Using multicast in such an environment might sound contradictory. But multicast is a very efficient communication paradigm to minimize the transmission delays. Also, multicast reduces the workload at the sender. Content delivery according to receiver interest can be achieved by group management in multicast. But the natural dynamics of the application results in numerous delays because of join/leave latencies. In this paper, we propose the Router Level Filtering as a solution to the above problem. RLF relies on an extension to the current IP multicast service model. It introduces "filters " in the router forwarding process thereby providing a simple effective mechanism to customize the data delivered to a multicast session receiver while minimizing the number of groups and the related management cost. Contrary to other router filtering proposals, the filter semantics is determined by the application. The paper discusses protocol specification and implementation details of RLF, and shows how it may be implemented in routers