P2P 之 UDP穿透NAT的原理与实现；

包括client to server and client to server.

//其中client to client: p2p的消息传递和udp打洞实现。

// client to server:客户端的登记；客户端节点链表的分发；udp打洞命令的请求和分发。

// 对客户端的数据接收和发送采用不同线程来实现

//服务器的模式是：处于循环接收信息和处理消息的状态。-P2P the UDP for NAT Traversal Principle and Implementation　including client to server and the client to server// in which the client to the client: p2p message passing and udp holes to achieve.// Client to server: client registration　the distribution of the linked list of client nodes　udp holes command requests and distribution.// Receive and send data on the client using a different thread// server model are: the state in the loop to receive information and process messages.