Networked games - A QoS-sensitive application for QoS-insensitive users?

Research into providing different levels of network Quality of Service (QoS) often assumes that there is a large market for QoS-sensitive applications that will be fulfilled once QoS-enabled networks have been deployed. Multiplayer networked games are an example of such an application that requires QoS, and hence will only become popular if QoS is made widely available. The prima facie evidence, however, is that games are already popular, in spite of the existing QoS-free best-effort Internet. Networked games may have become popular despite the lack of QoS because players "make do" with what is available to them. Such popularity is a double-edged sword. It may mean that there is a demand, as yet unfulfilled, from game players for QoS-enabled networks. On the other hand, it may mean that players have become accustomed to playing games without QoS, and therefore might be less willing to pay for higher QoS when it does eventually become available. In this paper we present the results of a short experiment to examine the QoS tolerances of game players. We use a set of popular First Person Shooter (FPS) game servers that are publicly available to Internet users at large. By systematically altering the network latency to the servers, we attempt to study whether degraded QoS (in the form of higher network delay) affects a user's decision to participate in the game. We find that increased network delay has an effect on a user's decision to join a game server. It appears, however, that there is no significant difference in the number of players who leave the game as a result of increased delay. We speculate that this may be due to a user's enjoyment exceeding their QoS-sensitivity, and discuss the implications of our findings with respect to providing and charging for QoS.