How do SIP Trunks work?

Roland_Ian — Wed, 07 Jan 2026 09:46:27 GMT

SIP Trunks are an application layer protocol which facilitate two-way conversations or multiple people on a conference call to communicate via audio or video over an IP network.

In Sinch SIP trunking service the incoming call legs and outgoing call legs is to your own SIP infrastructure such as a SIP IP-PBX, SBC or similar equipment.

Using SIP trunking together with Callback API you can combine all different types of incoming calls and outgoing calls the Sinch platform supports, including:

Call recording
Conference rooms

Visit Sinch Developer site to learn more about SIP Trunking.

article How do SIP Trunks work? in Voice API

How do SIP Trunks work?