udp 和 TCP 函数封装。主要实现UTD和TCP的函数封装，优化了UDP和TCP编程，很实用的函数。-udp and TCP functions package. UTD and TCP to achieve the main function of packaging to optimize the UDP and TCP programming, very practical function.

udp可靠传输实现方案，含有拥塞控制流量控制，超时重传-udp achieve reliable transmission program, which contains flow control congestion control, overtime ARQ