Signaling System No. 7 or SS7

Signaling System No. 7 (SS7) is a telephony signaling protocols which are used to set up most of the world's public switched telephone network telephone calls. The main purpose is to put the information required to set up and tear down telephone calls in a separate network rather than within the same network the telephone call is made on. Other uses include number translation, prepaid billing mechanisms, short message service (SMS), and a variety of other mass market services. Today most new telephony services depend on the power and reliability of Signaling System No. 7. Key benefits include; reduced recurring charges, opportunity to enter new markets, network scalability and compatibility, and widespread network ubiquity.