Calls passing between cellular networks do not depend on SS-7 messages in the same way that local and long distance networks depend on SS-7.

Question

Quizplus · Accepted Answer

SS-7 (Signaling System No. 7) is a set of telephony signaling protocols used to set up and tear down most of the world's public switched telephone network (PSTN) telephone calls. It is also used in cellular networks to facilitate calls between mobile phones and between mobile and landline phones, thus calls passing between cellular networks do depend on SS-7 messages in the same way that local and long distance networks do.

Calls Passing Between Cellular Networks Do Not Depend on SS-7