### Answer This issue typically occurs when Retell cannot properly route the inbound call to your agent. Here are the most common causes and troubleshooting steps: 1. Check your inbound agent binding Ensure your phone number is properly bound to an agent. If no agent is bound to the number, the call cannot be routed and will fail. [(1) ]() 2. Verify your origination settings If you're using custom telephony/SIP trunking, check your origination (inbound) settings in your SIP trunk configuration. [(2) ]() 3. Review your SIP trunk configuration For custom telephony setups, ensure you're using the correct transport method when pointing to `sip:sip.retellai.com`: - TCP (Recommended) :

sip:sip.retellai.com;transport=tcp

- UDP:

sip:sip.retellai.com;transport=udp

- TLS:

sip:sip.retellai.com;transport=tls

4. Check your telephony provider logs Review the logs in your telephony provider's dashboard to identify any specific errors. 5. Verify agent configuration Confirm your agent is properly configured and published. You can check agent details via the dashboard or the List Voice Agents API. [(3) ]() If you're using a Retell-provided number (not custom telephony) , I don't have specific documentation on this exact issue. Could you share more details about your setup—are you using a Retell number or custom telephony?

​ To learn more, see the sources I considered: [[1] I need to receive calls using 3cx as telephony system](https://community.retellai.com/t/i-need-to-receive-calls-using-3cx-as-telephony-system/435) [[2] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) [[3] List Voice Agents](https://docs.retellai.com/api-references/list-agents) ​

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

### Answer If you purchased a Telnyx number through Retell (meaning Retell manages the number for you) , you would not have direct access to Telnyx's logs since the telephony relationship is managed by Retell, not your own Telnyx account. [(1) ]() For numbers purchased directly through Retell, call logs and troubleshooting information are available in the Retell dashboard under your call history. You can also retrieve call details programmatically via the API, which provides information like

disconnection_reason

, latency metrics, and transcript data. [(2) ]() However, if you set up your own Telnyx account with elastic SIP trunking and imported that number into Retell, you would access logs directly in your Telnyx portal/dashboard. [(3) ]() To troubleshoot your inbound call issue: 1. Check your Retell dashboard call history to see if the call was registered and what the disconnection reason was 2. Verify your phone number has an inbound agent properly bound to it in the Retell dashboard 3. Confirm your agent is published and active If calls are ringing 3 times and hanging up, this often indicates the call isn't being routed to an agent—double-check that your number has an agent assigned for inbound calls. Would you like help reviewing your agent binding or call history in the Retell dashboard?

​ To learn more, see the sources I considered: [[1] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) [[2] Register Phone Call](https://docs.retellai.com/api-references/register-phone-call) [[3] Telnyx](https://docs.retellai.com/deploy/telnyx) ​

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

### Answer Since your first call connected successfully but subsequent calls aren't reaching Retell at all (no entries in Call History) , this points to an intermittent issue at the telephony layer rather than your agent configuration. Possible Causes - **Concurrency limits**: If your account has reached its concurrent call limit, additional calls may be rejected before they register in Retell. [(1) ]() - **Telephony provider issues**: Since you purchased the Telnyx number through Retell, the routing is managed by Retell's infrastructure. Intermittent failures where calls don't even register typically indicate the call isn't reaching Retell's SIP server. [(2) ]() - **CPS (Calls Per Second) throttling**: If you're making calls in rapid succession, you may hit rate limits. [(1) ]() Recommended Steps 1. Wait a few minutes between test calls to rule out any temporary throttling 2. Check for any active calls that might be consuming your concurrency allocation 3. Verify the number is still bound to your agent in the dashboard (sometimes bindings can become stale) 4. Contact Retell support with your call ID from the successful call (

call_556ca2cbdf0d37b47d1419be972

) and the timestamps of your failed attempts—they can investigate on the backend since you don't have direct access to Telnyx logs for Retell-managed numbers Since calls that don't appear in Call History never reached Retell's system, this is likely a telephony routing issue that Retell support would need to investigate on their end.

​ To learn more, see the sources I considered: [[1] Outbound Calls (Make Calls)](https://docs.retellai.com/deploy/outbound-call) [[2] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) ​

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