The Telnet protocol is analyzed which includes network virtual terminal, option negotiation and symmetry. Its application in Network Monitoring System is realized using VC 6.0.

• 简析了Telnet协议的组成；包括网络虚拟终端、选项协商和对称性；结合协议原理；在VC6.；0环境下实现了其在网络监控系统中的应用。