说明：  NS2与网络仿真 ns2是一种免费开源的网络仿真工具 相比较opnet有很大的灵活性 该书详细介绍了如何在ns2下构建网络仿真平台以及编写仿真代码构建仿真场景
(NS2 network simulation with ns2 is a free open source network simulation tool OPNET compared to the book has a great deal of flexibility described in detail how to build a network under ns2 simulation platform and the preparation of building a simulation scenario simulation code)