I'm running into an issue with outbound calls using the Vapi /call API endpoint. When I use a Twilio number, everything works as expected and the call connects. But when I try using a Vapi-provisioned number the call fails with this error: call.in-progress.error-sip-telephony-provider-failed-to-connect-call I confirmed that the number is correctly assigned to my assistant, and the API call returns a 200-level success. But the call doesn't actually connect. Is there something additional I need to do to enable outbound PSTN calling on Vapi-owned numbers?

Outbound calls using Vapi-owned numbers may fail due to SIP issues, rate limits, or number restrictions, ensure the number supports outbound PSTN (US-only for free numbers).

thanks @Kings_big💫 . Is it possible to get around this?

You will need to bring your own number.

update: was able to make outbound calls with VAPI numbers as of yesterday. i do have my own twilio number but there's more latency compared to the numbers bought directly inside of VAPI. I did escalate my issue to VAPI support. Still waiting for a bit more info. From a technical standpoint Twilio is stable, but the added latency makes for awkward exchanges IMO. Outside of Twilio, have others had success with other SIP providers?

Hey jonjon, could you help me with your current issue? If you can share call IDs, it will be really helpful to debug and reduce the time to resolution.