When Tropo sends a WebAPI document to your server, the content-type of the HTTP request will always be
application/json encoded with a UTF-8 character set. Likewise, when sending a JSON response, your web server should set the content-type to
application/json and set an appropriate character set. A common issue with incorrect character sets is an application using characters with accents or sending non-Latin characters such as Japanese or Cyrillic. Because most web servers default to serving ISO-8859-1 encoding, Tropo then decodes this expecting Latin characters. This causes text to speech, SMS messages, and speech recognition grammars to behave strangely, as the character conversion fails.
Access and Authentication
The web server URL that you configure in your Tropo application must be reachable over the public internet in order for Tropo to send the WebAPI document to it. URLs you include in your WebAPI response for things like your continue URL or for audio prompts must also be reachable over the public internet.
Tropo does not provide a static list of IP addresses where the WebAPI request will come from. If you would like to either restrict public access to your Tropo application or to verify that the request to your web url is coming from Tropo, you can use our DNS-based method for seeing the current list of IP addresses that are serving Tropo traffic.