Abstract
Multiplayer games are representative of a large class of distributed applications that suffer from redundant communication, bottlenecks and poor reactivity to changing network conditions. Many of these problems can be alleviated through simple network adaptations at the infrastructure level. In our model, game packets are directed along the edges of a tree connecting the players, aggregated and multicast as necessary. This three is heuristically formed, and is dynamically adjusted in response to changes in network conditions. We have designed and implemented a prototype using ANTS that performs these adaptations for unmodified DOOM clients. Active networks is currently the only open architecture suitable for these types of applications. We present analytical results that illustrate of reduction in communication overhead, and show that the multicast tree can quickly adjust to changing network conditions. The overhead of the active networks layer is acceptable, especially in wide-area networks.