SIP Trunking (Session Initiation Protocol Trunking): A method of connecting an existing on-premises PBX to the internet, enabling VoIP calling and expanding communication capabilities. It leverages the SIP protocol to transmit voice and multimedia sessions over the internet.
Analogy: Upgrading an old phone system with a digital adapter.
Why It Matters: Offers a way to transition to VoIP while retaining an existing PBX infrastructure.