IDEM: an Internet delay emulator approach for assessing VoIP quality

Network emulations are imitations of real-time network behavior that help in testing and assessing protocols, and other network related applications in a controlled hardware and software environment. Most of the emulators existing today are hardware implemented emulators. There is a rising demand to emulate the network behavior using a software tool. Our Internet delay emulator (IDEM) is a software tool that captures the network details and reproduces an environment useful for research oriented projects. IDEM is based on bouncers that are distributed over the Internet. The concepts of firewall routing are used in designing IDEM. IDEM supports both TCP and UDP applications. Rigorous testing shows that actual delay in data sent is accurately modeled by IDEM. Advantages of IDEM especially for delay sensitive applications like VoIP are discussed.