Toon Coppens

Access network delay in networked games

The end-to-end delay (also referred to as latency) experienced by gaming users has a significant impact on the quality of online games. In this paper we concentrate on the delay introduced in access networks. This access network delay depends on the access technology used, the network load, the link rate configured on the access links (also referred to as the last mile link) and the size of the packets generated by the games. We characterize this access network delay by means of measurements. First, we focus on this delay in actually deployed access networks: dial-up, cable and Asymmetric Digital Subscriber Line (ADSL) access. In these access networks the access network delay shoots up as soon as the gaming user (or somebody else on the users home network) saturates the users last mile link with traffic generated by applications (e.g. web browser) other than the games. Therefore, we also characterize the access network delay in a laboratory set-up of a QoS-enabled ADSL network. In this set-up we show that it is possible to (logically) segregate the game traffic from the other traffic to such an extent that the game packets are not excessively delayed while at the same time a large part of the link capacity can be consumed by the other traffic.