- Why is my NCCO being requested from my answerUrl multiple times?
- Why does my call fail with "failed to retrieve the ncco"?
- Will Nexmo retry the NCCO download request if my answerUrl fails?
- Why do my calls fail after 1 second?
- Why am I getting "General SSLEngine problem"?
- Why is the event callback being sent to my fallback answerUrl?
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 a further two times if:
- The request times out after 5 seconds
- The connection/socket has been closed or reset before the request has been fulfilled
- Your server responds with 429, 503 or 504.
Nexmo will not retry the GET or POST request if:
- Your server responds with an HTTP response stating an error other than 427, 503 or 504 (e.g. 404, 401, 500...)
- 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 or eventUrl 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.)
If your answerUrl or eventUrl fails to return a 200 OK or returns an invalid NCCO, and you have provided a fallback answerUrl, this will then be used to request the NCCO.