Quality of service agents in the internet

Abstract: The Internet is a multi-purpose communication network supporting users and applications with different service demands. To meet these demands, mechanisms for service differentiation in the network are proposed. This thesis presents an admission control architecture where clients can make resource reservations through agents. For each domain in the network there is an agent responsible for admission control. The architecture provides scalable resource reservations for virtual leased lines. Reservations from different sources to the same destination domain are aggregated in agents as their paths merge toward the destination. We support advance reservations where resources are shared between advance and immediate reservations without being pre-partitioned. Immediate admission control uses information about resources to be allocated for advance reservations in the near future and, if necessary, makes resources available by rejecting immediate requests. In rare cases, immediate reservations are preempted. Simulations show the cost in terms of resource utilization, rejection probability and preemption probability.