此仿真为ubantu系统下的REAL仿真（网络链路的仿真），本工程可以了解网络中流量控制的基本方法；用C语言实现TCP的拥塞控制算法；设计选择性重传协议，并用C语言实现。-This simulation ubantu REAL system simulation (simulation of the network link), the project can understand the basic method of network flow control　TCP congestion control algorithm using C language　design selective retransmission agreement with C language .