80911: Call To Message Only Session Rejected

Twilio returns this warning when an inbound voice call reaches a Proxy Session whose mode is message-only. Proxy Sessions can use message-only, voice-only, or voice-and-message. A message-only session does not accept voice traffic, so Proxy rejects the call.

• Your application created the Session with mode set to message-only.
• An out-of-session callback created the Session in message-only mode, and a participant then placed a call to the Proxy number.
• The Twilio phone number assigned to the Proxy workflow is still routing inbound voice traffic to Proxy through its voice configuration, even though the session is intended for messaging only.
• The Proxy number pool or workflow was set up for SMS use, but callers are also using the same number for voice.

• If participants need to call each other, create the Session with mode set to voice-and-message or voice-only.
• If you auto-create Sessions from an out-of-session callback, return session data with a voice-capable mode when you expect calls.
• If the workflow should stay SMS-only, update the Twilio phone number's voice configuration so inbound calls go to your own voice_url or voice application instead of Proxy.
• Use Twilio phone numbers with the capabilities required for your workflow. If you need masked calls, make sure the numbers in your Proxy pool support inbound voice.

• Proxy Session resource
• Proxy Quickstart
• IncomingPhoneNumber resource