While SS7 deals with non-circuit switched data (messages are transported without a dedicated circuit established for that purpose), the function of the ISDN-UP (ISUP) is to control the circuit-switched voice or data connection services.

• ss7是处理非电路交换数据(传输消息时，没有建立用于该目的的专用电路)的，而isdn-up(isup)则实现控制电路交换语音或数据连接业务的功能。