I tried to complete a test call today with a number created with Twilio SIP Trunking and I got this error: An error occurred in this call: call.in-progress.error-sip-outbound-call-failed-to-connect Please assist.

Thank you for sharing the error message. To help diagnose the issue, could you confirm if you have whitelisted the required Vapi SIP server IPs (44.229.228.186 and 44.238.177.138) in your Twilio SIP trunk configuration? This is a common cause for outbound call failures with SIP trunking ([see documentation](https://docs.vapi.ai/advanced/sip/sip-trunk#network-requirements)). Source: - [SIP Trunking Network requirements](https://docs.vapi.ai/advanced/sip/sip-trunk#network-requirements)

Yes I whitelisted both IPs

That error usually means Twilio couldn’t reach your SIP endpoint or it rejected the call. Double-check your SIP trunk credentials, the URI, and that your server/firewall allows inbound SIP from Twilio’s IPs. Also make sure your trunk is registered and the SIP domain is correct

Thanks I have that fixed now.

Glad you were able to get this resolved. If anything else comes up or you need further assistance, we’re here to help.

hello , i am facing the same problem, could you please tell me howyou fixed it?

Sorry for the late response, I didn’t see your message. To fix the problem, I just deleted the phone number in Vapi and then following the instructions for importing the phone numbers the regular way. I kept the SIP Trunking setup in Twilio the same, I just imported the phone number differently and then it worked. Also make sure you have a paid plan on Twilio (if you’re just testing load it with $20), OR if you’re on a free plan only use the phone number in Twilio that you verified to make an outbound dial to. Those situations can be blocking your calls from connecting.