Critical sections in networked games

This work introduces the concept of critical sections for online first person shooter games (FPS). A critical section is a section of game-play which demands higher precision or tighter deadlines. Critical section traffic is more sensitive to network degradations than sections immediately preceding or following it. Critical sections provide game developers and network programmers a notion of relative priority of game traffic, and can identify segments whose preservation can lead to superior user perceived quality of playing FPS games on a network. By analyzing video-recordings of over 5 hours of FPS gameplay by 10 volunteers, we identify sections of FPS game-play whose degradation would cause inconsistent game-state updates resulting in user frustration. We observe that critical sections exhibit a pattern of occurrence and can account for upto 17% of game-play time. We next quantify the expected network induced degradations on critical sections for online FPS games on the Internet. Using traces from a deployment of FPS workloads on 50+ nodes in the Internet, we study network dynamics and their ensuing effect on critical sections. Using traces from this experiment, we derive the lower bound on potentially degraded game-play session on todays Internet. We argue that critical sections of FPS games can be preserved. This can allow a variety of network architectures to better deliver higher perceptual experience when deployed on the Internet. Overall, our results have implications for FPS game-design, network provisioning, and game quality evaluation.