Twilio’s Programmable Voice SIP product enables your advanced voice applications to initiate SIP sessions from the Twilio cloud towards your existing SIP communications infrastructure using TwiML and/or the REST APIs.
With Programmable Voice SIP, there are a couple of ways to connect your Twilio application to your SIP communications infrastructure.
<?xml version="1.0" encoding="UTF-8"?> <Response> <Dial> <Sip>sip:email@example.com</Sip> </Dial> </Response>
To start receiving SIP from Twilio towards your communications infrastructure, there is one major step you need to follow:
To ensure that your communications infrastructure doesn’t block communication, you must update your whitelist. See here for details.
Now that Twilio’s IPs are whitelisted in your system, your Twilio app can begin sending SIP traffic to your SIP communications infrastructure. If you are new to Twilio, it’s best to start out with <Sip> noun of the <Dial> for your first app. See here for details.
The following headers will always be added by Twilio to the outgoing initial INVITE request. You may optionally use these fields in your communications infrastructure.