In the frame-relay WAN environment,common telephone is connected with FXS interface of Cisco router,and Cisco IP telephone is connected with Cisco3550 switch. Fur-thermore,Voice over IP is realized by arrangement of Cisco call-manager.

• 在帧中继广域网环境下,以Cisco路由器的FXS接口连接普通模拟电话机,以Cisco3550交换机连接Cisco IP电话,并通过Cisco Call-Manager的部署实现Voice over IP。