Enhanced mirrored servers for network games

Abstract

The Mirrored Server (MS) architecture uses multiple mirrored servers across multiple locations to alleviate the bandwidth bottleneck in the Client/Server (C/S) architecture. Each mirror receives and multicasts player updates to the others, simulates the game, and disseminates the new game state to players. However, keeping the game state consistent between mirrors in the presence of network delay, and maintaining game responsiveness requires each server in MS to simulate the game multiple times for each game update, and additional times in the event of costly rollbacks. In this paper we propose the Enhanced Mirrored Server (EMS) architecture. Like in the Peer-to-Peer architecture, EMS allows peers to exchange updates directly, resulting in a higher tolerance to delay at the mirrors. We propose using bucket synchronization in the mirrors so that each server in EMS simulates the game only once for each update and does not require rollbacks. The server disseminates updates to clients only in the event of inconsistency, and thus its outgoing bandwidth is lower than in MS. Our EMS uses cryptographic techniques to provide security equivalent to C/S, and prevents the timestamp cheat possible in MS. Our analytical analysis and simulations show the advantages of EMS over MS.

Traffic free distributed interactive applications in client assignment problem

“…It permits to direct users' requirements for content to the appropriate server based on a specified set of parameters. The closeness principle, by means of which a request is always provided by the server that is contiguous to the client, can occasionally fail [18,19]. Certainly, the routing method linked with a request might take into account several parameters (like traffic while sending the packets, bandwidth, and servers' computational capability) in order to supply the best routine in terms of time of service, delay, etc.…”

Delaunay State Management for Large-Scale Networked Virtual Environments

“…The Mirrored Server architecture [18] is based on the idea of fully replicating all game states at several servers connected by a high-speed network. Servers exchange among themselves event messages with an event-based consistency model, and clients can connect to any server based on latency or load balancing considerations.…”

“…Enhanced Mirrored Server (EMS) [18] extends the mirrored server architecture by allowing users to exchange messages directly to reduce transmission delay and increase scalability. It utilizes selected super-peers called referees for update authentication.…”

Secure Referee Selection for Fair and Responsive Peer-to-Peer Gaming

“…With only one centralised trusted server, keeping the game consistent, persistent, and cheat free in C/S is straightforward [4]. Unfortunately, C/S suffers from the following limitations: bandwidth scalability -the server's incoming and outgoing bandwidth is a bottleneck as the publisher must provision sufficient bandwidth at one location, which is an expensive re-occurring cost [5]; processing scalability -the server's processing power is a bottleneck, as it must simulate the entire virtual world and perform Area of Interest (AoI) filtering for all players [1], [6]; responsiveness -redirecting updates through the server increases game delay; reliabilitythe server is a single point of failure for the system; and fairness -players geographically close to the server have an unfair advantage, as they will have better responsiveness than those situated further away [2].…”