In this paper we attempt to gain an understanding of the behaviour of users in a multipoint, interactive communication scenario. In particular, we wish to understand the dynamics of user participation at a session level. We present wide-area session level traces of the popular multiplayer networked games Quake and Half-Life. These traces were gathered by regularly polling 2256 game servers located all over the Internet, and querying the number of players present at each server and how long they had been playing. We analyse three specific features of the data: the number of players in a game, the interarrival times between players and the length of a player's session. We find significant time-of-day and network externality effects in the number of players. Player duration times fit an exponential distribution, while interarrival times fit a heavy-tailed distribution. The implications of our findings are discussed in the context of provisioning and charging for network quality of service for multipoint and multicast transmission. This work is ongoing.

Mobile, delay-tolerant, ad hoc and pocket-switched networks may form an important part of future ubiquitous computing environments. Understanding how to efficiently and effectively route information through such networks is an important research challenge, and much recent work has looked at detecting communities and cliques to determine forwarding paths. Such detected communities, however, may miss important aspects. For instance, a user may have strong social ties to another user that they seldom encounter; a detected social network may omit this tie and so produce sub-optimal forwarding paths. Moreover, the delay in detecting communities may slow the bootstrapping of a new delay-tolerant network. This paper explores the use of self-reported social networks for routing in mobile networks in comparison with detected social networks discovered through encounters. Using encounter records from a group of participants carrying sensor motes, we generate detected social networks from these records. We use these networks for routing, and compare these to the social networks which the users have self-reported on a popular social networking website. Using techniques from social network analysis, we find that the two social networks are different. These differences, however, do not lead to a significant impact on delivery ratio, while the self-reported social network leads to a significantly lower cost.

Challenges face the Internet Architecture in order to scale to a greater number of users while providing a suite of increasingly essential functionality, such as multi-homing, traffic engineering, mobility, localised addressing and end-to-end packet-level security. Such functions have been designed and implemented mainly in isolation and retrofitted to the original Internet architecture. The resulting engineering complexity has caused some to think of 'clean slate' designs for the long-term future. Meanwhile, we take the position that an evolutionary approach is possible for a practical and scaleable interim solution, giving much of the functionality required, being backwards compatible with the currently deployed architecture, with incremental deployment capability, and which can reduce the current routing state overhead for the core network. By enhancing the way we use naming in the Internet Architecture, it is possible to provide a harmonised approach to multi-homing, traffic engineering, mobility, localised addressing and end-to-end packet-level security, including specific improvement to the scalability of inter-domain routing, and have these functions co-exist harmoniously with reduced engineering complexity. A set of proposed enhancements to the current Internet Architecture, based on naming, are described and analysed, both in terms of architectural changes and engineering practicalities.

Optimised link state routing (OLSR) is a popular protocol for use in MANET networks. In this paper, we investigate the different impacts of tuning refresh interval timers on OLSR performance under various scenarios (varying node density and node speed). Based on the simulation results with NS2, we find that although reducing refresh intervals could improve OLSR's performance, the intervals for some message types (HELLO messages) have a bigger impact on OLSR performance than for other message types. We find that the impact of the interval timer grows with increased network mobility and node density