With Twilio SIP, it’s simple connect to your SIP endpoints from a Twilio app. You can use TwiML or the REST API to initiate SIP sessions into your existing SIP gateways and IP PBXs. Take an inbound phone call and turn into a SIP call with TwiML. If you don’t have an existing phone call, use the REST API to start a new SIP call to your system.
To receive SIP from Twilio, use the <Sip> noun of the <Dial> verb to initiate a connection to your system. Twilio will send an INVITE to the URI you set in the <Sip> noun and attempt to establish a SIP session. Use this to take any existing phone call in Twilio and route it to your SIP endpoint.
To initiate a SIP connection without having an existing call, you can use the REST API to make SIP calls. This is just like making regular phone calls on Twilio, but instead of passing a phone number to dial, you just pass the URI to which we should send an INVITE.
To start receiving SIP to Twilio, you need to go through these steps: