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Now You Can Add Programmable Voice Participants to Video Group Rooms


We’ve heard from customers who’ve built apps with Twilio Video that they’d like to add in callers from SIP or the PSTN (Public Switched Telephone Network), as there are times where Participants would like to dial-in to the Room from a telephone.

Starting today, you can now connect Participants from the PSTN or over SIP audio to Programmable Video Group Rooms or Small Group Rooms (for simplicity in this post we’ll refer to both Room types as Group Rooms).

Now, with just a few lines of code, you can:

  • Receive phone calls to a Video Group Room from any Twilio phone number
  • Make outbound phone calls to add Participants to a Video Group Room.

PSTN/SIP Participants will be able to share their audio to the Video Group Room and will receive a mixed audio stream from the other participants connected to the Room.


New TwiML Verb

To connect the PSTN/SIP callers to Twilio Video Group Rooms we have created a new TwiML verb, <Connect>. This enables you to specify which Room you want callers connected to. Nested under <Connect>, the <Room> noun specifies the Room the Voice Participant will join. If you haven’t used TwiML before, learn more here. In response to the TwiML webhook request to an inbound or outbound call, you need to serve the following TwiML to connect the Participant to a Video Group Room.

    <?xml version="1.0" encoding="UTF‐8"?>

More Collaboration

There are many use cases where dialing into a Group Room is advantageous. In low-bandwidth applications call quality can often be improved if a Participant can dial in via the PSTN, but outside of that, the use case most often requested is for collaboration apps. Those familiar with the conference call, will be familiar with the ubiquitous dial-in number and the ease of connectivity it brings for Participants that don’t want to download your app. Having a dial-in makes it so much easier to get people connected on time.


Callers who connect to Video Group Rooms over PSTN or SIP will get charged the relevant Programmable Voice rates for their inbound or outbound call leg along with Video Group Rooms Participant minute charge. 

Small Group Rooms too?

Yes! Everything here applies to Small Group Rooms too. But sorry, you can’t dial-in to Peer-to-peer Rooms since we don’t have access to the media.

Can’t wait to get started?

Programmable Voice interoperability is available today. Use any of the Twilio server-side Helper libraries to generate the TwiML required.

We can’t wait to see what you build!

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