jspωiki
Signalling System No. 7

Overview#

Signalling System No. 7 (SS7) is a set of Telecommunications signaling protocols developed in 1975, which is used to set up and tear down most of the world's Public Switched Telephone Network (PSTN) telephone calls.

Signalling System No. 7 is part of the common-channel signaling (CCS)

Signalling System No. 7 also performs number translation, Local number portability, prepaid billing, Short Message Service (SMS), and other mass market services.

Common Channel Signalling System 7 (CCSS7) is how Signalling System No. 7 is referred to in the United States and In the United Kingdom, it is called C7 (CCITT number 7),

What does Signalling System No. 7 do?#

Signalling System No. 7 is a set of protocols allowing phone networks to exchange the information needed for routing data between each other and to ensure correct billing.

Signalling System No. 7 also allows users on one network to roam on another, such as when travelling in a foreign country.

Signalling System No. 7 Vulnerability#

Ed Snowden’s 2013 document dump revealed that the National Security Agency was using Signalling System No. 7 for Surveillance on individuals.

There have been several SS7 hacks.

More Information#

There might be more information for this subject on one of the following: