SS7, or Signaling System No. 7, is a set of protocols used in telecommunications to facilitate the exchange of information between network elements. It plays a crucial role in establishing and managing phone calls, text messages, and other services in traditional telephone networks. SS7 enables features like call forwarding, number translation, and mobile roaming. The system operates by sending signaling messages over a dedicated network, separate from the voice or data traffic. This allows for efficient communication between different service providers and ensures that calls can be routed correctly. However, vulnerabilities in SS7 have raised concerns about security and privacy in mobile communications.