PIN checking occurs by passing the developer’s URL along with the application PIN to a PIN checking VoiceXML document which is set in the configuration web page for Developer Applications. This occurs by changing the first URL within the applications list of URLs, for example:
http://hostname/vxml/sandpit_intro.vxml?url=http://hostname2/test.vxml&application=1234
Where http://hostname/vxml/sandpit_intro.vxml is the PIN checking URL as set within the Developer Applications configuration web page, http://hostname2/test.vxml is the developers VoiceXML application, and 1234 is the application PIN.
The true URL can be seen on the Applications page, if there is more than one URL specified then the others are left unchanged.