In my last blog post, Registering a SIP Phone Directly to Twilio (and so much more...), we set up a Twilio Programmable Voice SIP Domain and registered our SIP softphones directly to Twilio. This let us place and receive calls to the Public Switched Telephone Network (PSTN) but more importantly, set up the foundation for building creative applications which intelligently route calls using dynamically returned Twilio Markup Language (TwiML).
In this post we’ll provide a step-by-step approach to connect your SIP element – IP-PBX, SIP-PRI IAD, SBC, etc. – to Twilio’s Elastic SIP Trunking product. By the end of this post, you’ll have your existing communications infrastructure connected through Twilio and ready to layer on a number of Twilio’s other features.
At its most basic level, Twilio Elastic SIP trunking provides dynamic trunking capacity to place and receive pay-as-you-go phone calls through Twilio. Twilio’s network …
Twilio Programmable Voice SIP Domains, sometimes referred to as SIP Interfaces, allow you to place and receive voice calls using a standards based SIP endpoint by registering directly with Twilio.
Along with the ability to register directly with Twilio, you have the flexibility to choose the termination transport. This may include the traditional public switched telephone network (PSTN), another registered SIP device (often referred to as a SIP user agent [UA]), or even a Twilio Programmable Voice SDK endpoint. Connect all the things, indeed!
In this blog post we will:
- Register a SIP phone directly to Twilio
- Place and receive calls from a registered SIP phone
- Cover recommended design approaches
- Provide two different methods for delivering SIP Domain phone calls
- Discuss the benefits and current limitations using Twilio SIP Domains
Prerequisites to working with SIP Domains and Twilio
To accomplish the tasks in this blog post you will …