I'm experiencing an issue where all outbound calls...
# ❓・ai-evy-supportl
Louie
12/16/2025, 6:54 PM@AI Evy I'm experiencing an issue where all outbound calls are immediately failing with "Dial_no_answer" status and calls are not appearing in my Twilio call logs at all.
My setup:
Phone number: +34 911 67 65 40 (Spanish number)
Connection method: SIP Trunk
SIP Trunk name: Sinedent Retell SIP Trunk
Agent: Sinedent Event Agent
The issue:
Calls show "Dial_no_answer" immediately
Disconnection reason shows "Dial_no_answer"
Call status shows "Not_connected"
User sentiment shows "Unknown"
No transcript is generated
No calls appear in Twilio's call logs — the call never seems to reach Twilio
What changed:
This was working perfectly until I recently registered this same Twilio number for WhatsApp Business through Meta verification. Since completing that process, voice calls have stopped working entirely.
Troubleshooting I've already done:
Confirmed the number is still active and connected in Retell
Disconnected and reconnected the number in Retell multiple times
Verified all SIP trunk settings in Twilio are correct
Tested calls directly from Retell playground (not through any external automation) — same failure
Checked Twilio voice configuration — SIP Trunk is selected and routing is active
Confirmed the number still shows voice capability enabled in Twilio
Since calls aren't appearing in Twilio logs at all, I believe the issue is happening on Retell's side when attempting to initiate the call through the SIP trunk. Could the WhatsApp Business registration have affected how this number connects via SIP trunking? Is there something I need to reconfigure?
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AI Evy
12/16/2025, 6:54 PMThanks for tagging me @Louie. I'll look through relevant sources and get back to you shortly.
AI Evy
12/16/2025, 6:54 PM### Answer
Based on your description, the fact that calls aren't appearing in Twilio logs at all suggests the issue is likely with the SIP trunk termination configuration rather than Retell itself. Here are the key areas to verify:
1. Check Your Termination SIP URI [(1) ]()
- Ensure there's no space in your Termination SIP URI
- Use a localized termination URI near your region (Spain) . Check Twilio's [localized URIs documentation]() to select the appropriate one
2. Verify Credentials
- Double-check your username and password credentials
- The username is not the friendly name shown in the credential list—these are different values, so verify you're using the actual username
3. Re-import the Number to Retell
Since you mentioned disconnecting/reconnecting, when you import the number back, ensure you supply:
- The correct termination SIP URI
- The correct authentication credentials (if using credential-based auth)
4. Check Twilio SIP Trunk Settings [(2) ]()
- Confirm "Code Transfer" is enabled
- Confirm "Enable PSTN Transfer" checkbox is ticked
- Verify the number is properly assigned to the SIP trunk under the "Numbers" section
Regarding WhatsApp Business Registration:
The available documentation doesn't specifically address conflicts between WhatsApp Business registration and SIP trunking. However, since the calls aren't reaching Twilio at all, this points to a configuration issue on the termination side.
Recommended Next Steps:
1. Delete the number from Retell and re-import it fresh with verified credentials [(1) ]()
2. Check your Twilio termination logs (not just call logs) for any errors
3. Open a ticket with Twilio to verify the
AI Evy
12/16/2025, 6:54 PM
To learn more, see the sources I considered:
[[1] Twilio](https://docs.retellai.com/deploy/twilio)
[[2] Retell AI - Connect to your own Twilio - Using Sip Trunking]()
AI Evy
12/16/2025, 6:54 PMnumber's voice capability wasn't affected by the WhatsApp registration
If issues persist after verifying these configurations, you may want to reach out for additional support:
- [Contact Sales]()
- [Retell AI GitHub]()
Would you like a general answer about troubleshooting SIP trunk connectivity issues?
AI Evy
12/16/2025, 6:54 PMFeel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.