Peer-to-peer architecture and protocol for a massively multiplayer online game

Massively multiplayer online games (MMOGs) are becoming a very important part of computer entertainment business. With recent development of broadband technologies, the increase of the number of players is putting a strong pressure on this type of applications. Commonly used clients/server systems do not cope well with scalability, limiting the number of players who interact with each other, are not robust enough and might be subject to bottleneck due to their centralized infrastructure. These systems also force the developers to invest enormous amount of money on hardware and time to design complex software systems. To solve these problems we propose a fully distributed, peer-to-peer architecture for MMOGs. In this paper we discuss the issues surrounding MMOGs, the limitations in term of network infrastructure, and the lack of simulation environment to study and evaluate network architecture and protocol. We use a peer-to-peer (P2P) based architecture and protocol to provide a more scalable, flexible and robust technology solution than currently used infrastructures. We have conducted the design and implementation of a modular MMOG: ´time-prisoners´, using a P2P protocol developed in Java and JXTA. The characteristics of P2P overlays enable to organize dynamically, and in transparent way for the users, the group of players according to their locations in the virtual world, and allow to design scalable mechanism to distribute the game state to the players and to maintain the world consistent in case of node failures.