NS2（Network Simulator, version 2）是一种面向对象的网络仿真器，本质上是一个离散事件模拟器。由UC Berkeley开发而成。-NS2 (Network Simulator, version 2) is an object-oriented network simulator, in essence, is a discrete event simulator. Made by the development of UC Berkeley.

用离散事件模拟银行柜台,使用了qt平台做出了GＵＩ(the simulation of bank with discrete event)