How to Enable Bidirectional Media Streams for Twilio Conference Calls Using a TwiML App? – Twilio Support

Question

How can I enable bidirectional media streams for PSTN calls which are part of Twilio conference calls using a TwiML App?

How to Connect Your Voice AI Agent to a Twilio Conference with Bi-Directional Media Streams Using TwiML Apps?

Product

Programmable Voice

Answer

To enable bidirectional media streams for PSTN calls with Twilio Media Streams, you need to use a TwiML Application with the <Connect><Stream> verb in a conference setup. This approach allows you to both receive audio from the caller and send audio back to the caller in real time. The recommended steps are:

Start a conference for the call ( for example, using <Dial><Conference> )
Add a participant to the conference via the Conference /Participants endpoint, where the TO parameter for the participant is set to app:<APP_SID> that will provide the next instructions
The TwiML Application should return <Connect><Stream>, which enables the media stream

<Response>
   <Connect>
       <Stream url="wss://example.com/audiostream" />
   </Connect>
</Response>

3. Your server can then receive and send audio in real time through the media stream

Additional Information

For more details and step-by-step instructions, see Twilio’s guide on connecting a TwiML App to a Twilio Conference.