普通的交换机,其主要功能是完成呼叫连接,即根据主叫所拨的被叫号码进行路由选择,完成主被叫的通话连接。我们可以通过对交换机进行软硬件的升级来实现一些增值业务,例如主叫号码显示、热线、Centrex等。但是通过这种方法提供的增值业务,其业务实现与交 Ordinary switches, its main function is to complete the call connection, that is called according to the called number dialed by the calling route, to complete the called call connection. We can realize some value-added services such as calling number display, hotline, Centrex and so on through the hardware and software upgrade of the switch. But through this method to provide value-added services, their business and pay