Innovative network emulations using the NCTUns tool

Network emulation is an important research approach. It allows real-world traffic to interact with simulated traffic and experience various user-specified packet delaying, dropping, reordering, and duplication treatments. With emulation, one can test the function and performance of a real-world network device under various simulated network conditions without the need to get, know, or modify its internal protocol stack. Due to these capabilities, emulation is widely used to test network protocols and network devices. In this chapter, we introduce NCTUns, an innovative network simulator and emulator. We explain the novel simulation methodology used by it, present its design and implementation, and show its emulation capabilities and performance. Several examples are presented to illustrate its uses in wired and wireless network emulations.