There was a network failure attempting to connect to this URL. Twilio will try for 10 seconds to establish a TCP connection to your URL (two 5 second attempts). Twilio will wait for a total of 15 seconds to receive an HTTP response, this includes the TCP connection time, so if it took six seconds to establish a TCP connection, your server would have 9 seconds to deliver an HTTP response. If either of those timers expire we fail the request, fire a notification, and try your Fallback URL, if one is specified.
- network outages between Twilio and your web server
- URLs that reference private IP addresses or localhost
- Twilio's TCP timeout is 10 seconds; so if you see an error in Request Inspector after > 10000 milliseconds Twilio could locate your server, but could not establish a TCP connection with it.
- Twilio's HTTP timeout is 15 seconds; if you see an error in Request Inspector returned after > 15000 milliseconds, Twilio was able to establish a TCP connection with your server, but the HTTP response from the server failed.
- verify the URL provided is accessible to the public internet
- verify network connectivity to your web server
- check your TCP logs to verify inbound connection attempts are successful
- check HTTP server logs to verify a response was generated and returned within the timeout
- check your edge element logs to verify responses are making it out of your infrastructure