A policy controlled IPv4/IPv6 network emulation environment

In QoS enabled IP-based networks, QoS signaling and policy control are used to control the access to network resources and their usage. The IETF proposed standard protocol for policy control is Common Open Policy Service (COPS) protocol, which has also been adopted in 3GPP IP Multimedia Subsystem (IMS) Release 5. This paper presents a prototype for policy-controlled IPv4/IPv6 network emulation environment, in which it is possible to specify the policy control and emulate, over a period of time, QoS parameters such as bandwidth, packet delay, jitter, and packet discard probability for media flows within an IP multimedia session. The policy control is handled by COPS, and IP channel emulation uses two existing network emulation tools, NIST Net and ChaNet, supporting IPv4 and IPv6 protocols, respectively. The scenario-based approach allows reproducible performance measurements and running various experiments by using the same network behavior. A graphical user interface has been developed to make the scenario specification more user-friendly. We demonstrate the functionality of the prototype emulation environment for IPv6 and analyze its performance.