SLA Admission Controller for Reliable MPLS Networks

This paper introduces a reliability conscious Service Level Agreement (SLA) based admission controller for data networks. Previous research on optimal SLA admission control is discussed, especially the modeling of the admission control problem as a type of Knapsack problem and control architectures developed on this principle. To provide provisions for reliability, the basic SLA specifying a user’s desired Quality of Service (QoS) is extended to include reliability requirements. To provide for these, an existing SLA-based admission controller is extended to calculate multiple alternate paths for each session and perform resource reservation on all these paths. In the event of node or link failure, a session can now be quickly switched to one of the alternate paths, maintaining the guaranteed QoS without having to run the full admission algorithm again. Simulations are presented which investigate the impact on system performance and the gains made in reliability.