Design and implementation of MPLS network simulator (MNS) supporting QoS

Multiprotocol label switching (MPLS) is known as one of the most important technologies for solving many problems over the Internet. Many efforts and activities on MPLS have been initiated, which prompt the necessity of the MPLS simulator. We propose an MPLS network simulator (MNS) built on the NS, which supports QoS as well as basic MPLS functions such as label switching, label distribution protocol (LDP), constraint-based routing-label distribution protocol (CR-LDP), and various options of label distribution. This paper describes the design and implementation of MNS, focusing on its components; those are CR-LDP, MPLS classifier, service classifier, admission control, resource manager, and packet scheduler. To verify the accuracy and efficiency of MNS, two examples are simulated and evaluated. One is the simulation for several kinds of traffic with different QoS. The other is the simulation for resource preemption