Abstract: In order to emulate the communication of WANs within LAN environment, a Linux-based large-scale WAN emulation system with strong extensibility is designed, which can be applied to controllably emulate the actual properties such as delay, jitter and packet loss in WANs. A structure which is convenient for distributed networking and extending is built in the emulation system. The key functionalities in large-scale network emulation are designed and implemented, such as dynamic transparent routing, channel properties emulation and traffic monitoring. The testing results show that it is effective to emulate and manage the communication properties among multiple networks, which facilitates the debugging and testing of protocols or software in WANs.
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Key words: WAN, network emulation, network testing, traffic monitoring, HTB algorithm, Linux