客户机/服务器模型是为了解决通信中的聚合问题。如果不采用客户机/服务器模型很难实现正常的通信，只有在一方作为服务器采用被动方式，始终等待对方与其通信；另一方作为客户机采用主动通信的方式，主动发起通信过程，才能最终完成通信。-client / server model is to solve the communication problems polymerization. If we do not use the client / server model is very difficult to achieve normal communications, as one of only a passive server, which has been waiting for communication with the other side; The other client as an active communication, initiate the communication process can be finalized communications.