The number of telephone lines connecting the subscriber's terminal equipment to the publicswitchednetwork and which have a dedicated port in the telephone exchange equipment.
连接用户终端设备和公用交换网并具有一个电话交换设备专用端口的电话线数。
2
The call forwarding sample demonstrates the call forwarding feature typically seen in publicswitched telephone networks, but it USES a SIP network.
As voice communications is the primary media of communication for human being, it plays a very important role from publicswitched telephone network to the third generation mobile communications.