The performance of software multicast-reflector implementations for multi-player online games

Massive multi-player online games are large distributed applications where thousands of participants exchange data. Existing solutions based on central servers face scalability problems. We study a hybrid solution between the peer-to-peer and central server models that divides a large game into several federated small games. The central component of this architecture is a multicast reflector. We present two efficient software implementations that have been developed as Linux kernel extensions and compare them with our user-space implementation. The comparison is based on performance measurements done on actual implementations.