What happens if the NCCO download request fails?


  • Why is my NCCO being requested multiple times?
  • Why does my call fail with "failed to retrieve the ncco"?
  • Will Nexmo retry the NCCO download request if it fails?
  • Why do my calls fail after 1 second?
  • Why am I getting "General SSLEngine problem"?



If the Nexmo Voice API encounters an issue when downloading your NCCO using GET or POST, depending on the method you have configured in your Application or the method that has been set in your API request, it may reattempt the request.

Nexmo will retry the GET or POST request if:

  • The request times out after 5 seconds
  • The connection/socket has been closed before the request has been fulfilled

Nexmo will not retry the GET or POST request if:

  • Your server responds with an HTTP response stating an error (e.g. 404, 503...)
  • Your NCCO has a syntax error (e.g. missing [ or invalid action)
  • The NCCO is encoded incorrectly (e.g. text/html, application/xml...)
  • The answerUrl/answer_url is invalid
  • There is an issue with your SSL certificate (e.g. self-signed certificates without a certificate authority, intermediate certificate isn't being returned, etc.)
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