Design of Accurate and Efficient Network Emulation Systems with Application to Inter-planetary Networks

Many network emulators have been developed for performance evaluation of network protocols and distributed applications. While most of them specialize on some features targeted for certain applications, few of them address the overall accuracy and efficiency of a general-purpose network emulator. In this paper, we present the key elements of constructing an accurate and efficient general-purpose network emulator. We focus on the architecture of an emulator and the packet capture methods. We analyze the typical approaches a network emulator takes with emphasis on two outstanding distributed network emulators: NETShaper and EMPOWER. We present the functions we have added to NETShaper, namely zero bandwidth emulation and bit error rate emulation. Application of distributed network emulation to protocol design for inter-planetary networks is also discussed.