Efficiency of PCN-Based Network Admission Control with Flow Termination

ABSTRACT

The pre-congestion notification (PCN) architecture marks packets based on the utilization of links and gives early warnings before congestion occurs. The IETF suggest to implement network admission control (NAC) and flow termination based on this feedback to enforce quality of service (QoS) under failurefree operation and the manageability of the network in failure scenarios. Admission control decision are taken only at the border routers. In case of link or node failures, traffic is just rerouted and no reservation states need to be recovered inside the network. Therefore, PCN-based NAC can be operated in a resilient mode for a set of protected failure scenarios if sufficient backup capacity is reserved to accommodate the redirected traffic. This paper presents ongoing work in the IETF, relates it to the theory of resilient NAC, and investigates the efficiency of the new approach.