基于IP可靠组播的多点远程计算机控制系统研究与实现

Research and Implementation of Multipoint Remote Computer Control System Based on Reliable IP Multicast

虚拟网络计算 VNC(Virtual Network Computing)是 AT& T剑桥研究所研究并发布的一种基于 internet环境的远程控制软件包 ,能够在广域网上实现远端计算机的操作 ,控制安装在远程计算机上的仪器设备 ,并在控制的同时实时看到远端计算机的屏幕输出 .但是 VNC软件是建立在 TCP协议上的 ,只能够实现点对点的操作 .此文在兼容原有 VNC软件基础上 ,提出了单播 -组播代理 U MX模型 ,使用可靠组播技术设计并且实现了 VNC- Proxy,使得多个用户能够同时操作连接在远端计算机上的仪器 ,远端计算机的输出通过单播方式传给 VNC- Proxy,再由VNC- Proxy使用可靠组播方式传给各个远端用户 .与使用多个单播连接方式实现多点控制比较 ,基于可靠组播方式的

VNC(virtual network computing) is a remote accessing tool developed by AT&T Cambridge Laboratory. With the help of VNC, one can operate the instruments attached to a computer remotely and view the output of the remote computer in real time. However, the original VNC system is based on TCP protocol, which can only support peer to peer connections. In this paper, a UMX (unicast multicast proxy) model is described. An unicast multicast proxy, named VNC proxy, according to the UMX architecture is also developed. With the help of VNC proxy, the remote users can work cooperatively. The output screen images of the instruments is sent to the VNC proxy by unicast protocol and multicasted to the remote users by the VNC proxy in real time. Compared with the traditional unicast approach, the VNC proxy also significantly decreases the bandwidth consuming.