The increasing growth in computer networks has brought with it an increase in the interest and importance of online games. Most commercial games use a client-server architecture and many allow the players to connect their clients to their choice of game server. Given that players can also deploy their own server, many games provide players with a choice of many possible game servers. And server selection matters, not only for physical parameters such as player population and game map, but because the latency between the game client and the server has been shown to degrade gameplay. The selection process is made more difficult when players want to play together as a group, co-located on the same game server.
In order to enhance server browsing to support simultaneous players and consider alterations to support the increasingly wide-range of online games, there is first a need for a better understanding of the network characteristics of current game server browsing. This paper provides this needed first step by gathering data on real game servers and clients on the Internet. Months of master server data for three different games provide a characterization of server uptimes and populations, allowing observation of time of day and day of week correlations. A week of game server data gathered from custom software that emulates the server browsing of players seeking to play simultaneously on the same game server provides insight into the ability of currently deployed game servers to support online gameplay.
The results allow us to draw the following conclusions: 1) There is no visual day of week correlation to server uptime or player population. 2) There is no visual time of day correlation to server uptime, but there is some correlation with player population. However, there is not a corresponding correlation with server performance (latency). 3) Game server performance (latency) is nearly independent of game type and game generation. 4) The number of simultaneous players in a group directly reduces the performance for all players by increasing the maximum latency. 5) Game server pools are well-suited to support typical third-person games, such as role-playing games or real-time strategy games. The pool of available game servers for third-person games can fairly easily support up to 20 simultaneous game players. 6) Game server pools are not as able to support typical first-person games, such as first-person shooters or racing games. Players selecting a server outside of a group can find an adequate number of suitable servers, but the pool of servers that provide acceptable performance decreases rapidly with an increase in the group size.
Since the data obtained in this study has been made available to the public, additional processing of the data may provide other insights into game server browsing: 1) Game servers provide information on the latencies and scores of players currently connected to the server. This data can be analyzed to study the range of latencies currently in use, and perhaps correlated with user scores. Or, 2) Geographic information may play a role in the ease (or difficulty) in simultaneous users finding a suitable game server. Additional analysis could examine the physical relationship among the clients and servers, both geographically (in terms of physical distance) and topologically (in terms of network distance), to better understand server browsing. Some games have servers that are not setup or controlled by individual users, such as servers for one of the popular massively multi-player online (MMO) games. These servers typically have similar server selection issues and so may benefit from the analysis in this paper, but often have the selection done implicitly with a single head node re-directing players to appropriate servers. Study of server selection in this process, probably with support from industry, may be an interesting area of future work.