７号信令的功能及在交换机中的应用黑龙江省邮电学校宋红力随着通信网的综合化、数字化，信道信号的内容变得相当丰富，信令种类增加，用原有的随路传输方式来传递已不适应目前通信技术的发展需要。因此，采用７号公共信道信令，已成现代通信网形成与发展的必然。７号信令... The function of letter of 7 and its application in switchboard The telegraph school of Heilongjiang province Song Hongli With the integration of communication network, digitization, the content of the channel signal becomes quite rich, the letter kind increases, use the original way Transmission has not adapted to the current development needs of communications technology. Therefore, the use of No. 7 public channel signaling has become the inevitable formation and development of modern communications networks. 7th signaling ...