A study of flow-based admission control algorithm in the ATM-based MPLS network

Abstract

This thesis presents the DiffServ over ATM based MPLS core network architecture of combining Integrated Service (IntServ)/Differentiated Service (DiffServ) and conventional Best Effort service at the access network. The proposed network supports the integrated as well as differentiated services through ATM shortcut connection or MPLS label swapping using the capabilities of an underlying ATM network to realize Quality of Service (QoS). We proposed the ATM shortcut connection using ATM signaling for the guaranteed service class. An ATM shortcut refers to the ability to forward network layer packets (L3) directly at the link layer (L2), regardless of the existing network boundaries. This has a number of advantages, like higher throughput, shorter end-to-end delay, reduced router load, better utilization of L2 QoS capabilities, and route optimization. The proposed method can enlarge the performance of networks due to short hop count. In particular, the above ATM shortcut gets rid of the delay resulted from label swapping between other MPLS domains. We design DiffServ module which is classified and marked, policed and shaped and performed service mapping at Label Edge Router (LER) in order to accommodate all service classes. In this thesis, we discuss a DiffServ mapping and integrated packet scheduler. Also we propose a flow-based admission control algorithm that is suitable for multiple service class environments. This algorithm can be achieved two objects which are reliable delay bounded QoS provisioning and high resource utilization. Also, this algorithm reduces the reject probability of high priority service class flow in operating DiffServ. The proposed approaches guarantee a hard QoS using ATM shortcut connection for IntServ guaranteed service class and increase resource utilization according to per class QoS condition for other service classes.