### Answer --- The

dial_no_answer

disconnection reason means the outbound call was not connected because the number dialed did not answer. [(1) ]() Here are common things to check for your OVH SIP trunk setup: 1. Verify Termination Settings Check your termination setting in your SIP trunking provider and make sure you provided the correct termination URL to Retell. [(2) ]() 2. Check Termination URI Format Ensure there's no space in your Termination SIP URI. Also consider using a localized termination URI near your region. [(3) ]() 3. Verify Credentials If you're using credential-based authentication, double-check the username and password you entered when importing the number. Note that the username is not the friendly name that shows in the credential list—they can be different. 4. Check Origination Settings For inbound to work, your origination should point to Retell's SIP server:

sip:sip.retellai.com

[(2) ]() 5. Check Provider Logs Review the logs in your telephony provider (OVH) for more specific error details, and consider opening a ticket with them. Note: Retell will not throw errors if the configuration is incorrect until a call is actually made—there's no pre-validation of whether your setup works. Since OVH is not one of the providers with detailed guides in the documentation (Twilio, Telnyx, and Vonage have specific guides) , you may need to adapt the general elastic SIP trunking approach for OVH's specific requirements.

​ To learn more, see the sources I considered: [[1] Debug call disconnection](https://docs.retellai.com/reliability/debug-call-disconnect) [[2] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) [[3] Twilio](https://docs.retellai.com/deploy/twilio) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.