SS7 (Signalling System 7)

SS7 is the set of signalling protocols used by telephone networks worldwide to exchange control information — setting up and tearing down calls, routing SMS, managing number portability, and enabling roaming. Because SS7 was designed in the 1970s without security in mind, it contains well-known vulnerabilities that can be exploited for location tracking, call interception, and fraud. SS7 firewalls are essential for protecting networks against these threats.