This guide is intended to help troubleshoot any issues with Twilio Programmable Voice calls that don't connect that their destination. This guide covers the following topics for diagnosing and resolving your issues:
Please start at the top, and walk through each of the troubleshooting steps as you work your way down the page.
Check Your Call Logs
Check the Twilio Call Logs to validate that we have successfully received and processed a request for a call. You can view the logs and search for your call record via either Console, or the REST API.
A record does exist for the call, but the call doesn't connect: If you do see a record for the call in question, but the call destination isn't connected, then there is likely an issue elsewhere. Continue reading for additional troubleshooting.
A record does exist for the call: If you do see a record for the call in question, this indicates Twilio has successfully received the a request for a call, and the issue lies elsewhere. Continue troubleshooting with the following checklist:
- Are you troubleshooting an Elastic SIP Trunking or SIP Domain call?
- Are you (or a caller) hearing the "An application error has occurred” error on your call?
- Does the call log show any Debug Events?
- Is the Last SIP Response something other than
200 OKin Voice Insights or the Elastic SIP/SIP Domain Packet Captures?
- Is your TwiML URL or Application SID responding as intended?
- Are you (or a caller) experiencing any audio quality issues?
A record doesn't exist for the call: If you don't see a record for the call in question, then you'll need to troubleshoot why Twilio isn't registering the call request. For full details, please see the corresponding article:
- Troubleshooting Outgoing Twilio Programmable Voice Calls
- Troubleshooting Incoming Calls on a Twilio Phone Number
Check for Twilio Incidents
Check the Twilio Status Page to see if there is an active incident, or an incident during the timeframe you reported issues, that could be causing your issues. For full details, please see Checking Twilio Service and API Status with the Status Page.
No incidents are listed that may be affecting calls: If you don't see an incident posted that may affect calls, then there is likely an issue elsewhere. Continue reading for additional troubleshooting.
An incident may be affecting calls: If you see an incident posted that may affect outgoing Twilio calls, please monitor the status, and then test again once the incident is resolved.
Test and Collect Information
If there are no known Twilio issues, we will need to perform additional testing to determine issue reproducibility, variance, and frequency:
- Does you have issues connecting all calls, or just to specific phone numbers?
- Does this occur all the time to the same numbers, or does it seem more random?
All calls have trouble connecting: If none of your Twilio calls are able to successfully connect to any phone number, then there may have been an issue missed previously. Review the previous troubleshooting, and then continue reading if you are unable to determine the source of your problems.
Some phone numbers have trouble connecting: If you are able to place some successful calls, but specific phone numbers have issues with connecting successfully, then there is likely an issue elsewhere. Notate your testing results, and then continue reading for additional troubleshooting.
Connection issues are inconsistent: If you are unable to determine a pattern with connection issues, we will likely need to look into this closer. What are the commonalities between examples (service providers, locations, etc.)? Notate your testing results, and then continue reading for additional troubleshooting.
Escalate to Twilio Support
If you can rule out all of the above issues, Twilio's Support team can help investigate what went wrong. Please collect 3 or more examples of calls that are not registering in your call log from the last 24 hours, and include the following information:
- Caller (from) number
- Callee (to) number
- Your Twilio project Account SID
- Call SIDs
- Timestamps of call attempts
- Description of issue reported
- Reproducibility and frequency of issue
When you have collected this information, please share it with our Support team.