What happens if the NCCO download request fails?

Question

Will the Voice API retry the NCCO download request if my answerUrl fails?

Why do my calls fail after 1 second?

Applies To

• Voice API
• NCCO
• AnswerURL

Answer

If the 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.

The Voice API will retry the GET or POST request once more if:

• The connect times out
• The socket times out
• The connection/socket has been closed or reset before the request has been fulfilled
• Your server responds with 429, 503, or 504.

The Voice API will not retry the GET or POST request if:

• Your server responds with an HTTP response stating an error other than 429, 503 or 504 (for example, 404, 401, 500).
• Your NCCO has a syntax error (for example, missing [ or invalid action).
• The NCCO is encoded incorrectly (for example, text/html, application/xml).
• The answerUrl or eventUrl is invalid.
• There is an issue with your SSL certificate (for example, 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.