### Answer When outbound calls show

dial_no_answer

, it means the number dialed did not answer [(1) ]() [(2) ]() . This is different from reaching voicemail, which has its own disconnection reason of

voicemail_reached

[(1) ]() [(3) ]() . Common reasons for `dial_no_answer`: - The recipient's phone rang but they didn't pick up [(1) ]() [(2) ]() - The call timed out before anyone answered [(2) ]() - Network or carrier issues prevented connection Why some calls reach voicemail instead: Voicemail is detected when Retell's voicemail detection system identifies a voicemail greeting during the call [(3) ]() . You can configure how your agent handles voicemail through the agent settings by enabling Voicemail Detection and choosing whether to hang up or leave a message . Troubleshooting steps: 1. Check your call logs in the dashboard for the specific disconnection reason and SIP error codes [(2) ]() 2. If using custom telephony, verify your configuration is correct 3. For numbers purchased from Retell, ensure the destination number can accept calls (currently US numbers only) 4. Review if your numbers are being marked as spam, which can affect connection rates If you're experiencing a high rate of

dial_no_answer

errors, check the call detailed logs for SIP error codes that can help identify the root cause .

​ To learn more, see the sources I considered: [[1] Debug call disconnection](https://docs.retellai.com/reliability/debug-call-disconnect) [[2] Debug outbound connection issues](https://docs.retellai.com/reliability/debug-outbound-call) [[3] Handle voicemail and IVR](https://docs.retellai.com/build/handle-voicemail) ​

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

### Answer The error "SIP request timed out" with

user_no_answer

category indicates the SIP request didn't receive a response within the expected timeframe [(1) ]() . This specific error typically means: - The destination number's carrier/network didn't respond to the SIP INVITE request in time - Network routing issues between Retell and the destination prevented the call from completing - The telephony provider may be unavailable or experiencing issues Troubleshooting steps: 1. Check call detailed logs - Review the SIP error codes in your call history for more specific information about what failed 2. Verify telephony configuration - If using custom telephony, double-check your SIP trunk credentials and configuration are correct 3. Test destination reachability - Verify the destination number can accept calls and isn't blocking your number 4. Review ring duration settings - The

ring_duration_ms

parameter controls how long the phone rings before timing out (default 30 seconds, range 5-300 seconds) [(2) ]() [(3) ]() . You can adjust this in your agent settings if calls are timing out too quickly. 5. Check for spam marking - If your number is marked as spam, carriers may not route calls properly [(1) ]() If you're using custom SIP trunking with Twilio or another provider, some users have resolved similar timeout issues by deleting and reconnecting their SIP trunk configuration [(4) ]() .

​ To learn more, see the sources I considered: [[1] Debug outbound connection issues](https://docs.retellai.com/reliability/debug-outbound-call) [[2] Create Voice Agent](https://docs.retellai.com/api-references/create-agent) [[3] List Voice Agents](https://docs.retellai.com/api-references/list-agents) [[4] Outbound calls via Retellai API are not reaching Twilio.](https://discord.com/channels/1186424376300679209/1346516210615062650) ​

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