What is a SIP trunk?
A SIP trunk is a virtual phone line that connects a phone system to the public telephone network via the internet (VoIP). Instead of physical ISDN lines, calls run over the SIP protocol as data packets.
SIP trunks replace classic ISDN connections. They scale flexibly – you book as many simultaneous call channels as you need – and are usually cheaper, because no separate phone infrastructure is required.
For AI telephony, the SIP trunk is the technical bridge over which calls reach the voice assistant. Empfango integrates into existing telephony without you having to change your phone number.
Related terms
Virtual phone system
Manages calls in the cloud, without on-site hardware.
AI phone assistant
Answers calls on its own, understands the request and replies in natural language.
Voicebot
A voice-driven AI assistant that handles phone calls on its own.