FACE – First aid for the IVR


Mnemonics are a great way for remembering which steps to take in order to quickly handle a problem. A great example is “DR ABC”, which makes it easy to remember what to check for when providing first aid: Danger, Response, Airways, Breathing, Circulation. (see http://blogs.redcross.org.uk/first-aid/2009/11/dr-abc-the-doctor-of-first-aid )

First Aid for the IVR

The most common IVR problems can be handled by remembering “FACE”:

  • Firewall
  • Accept calls
  • Controller
  • Errors


When using VOIP telephony, make sure the firewall is not blocking calls. In some cases the signalling part of the call (SIP) can get through the firewall, but the audio streams (RTP) are blocked.


When the VoxCallAcceptDeny plugin is present in the plugins directory, the flow has to call the “Accept” function. This problem often occurs when a flow that uses the VoxCallAcceptDeny plugin is replaced with one that does not. If the VoxCallAcceptDeny plugin is still present in the plugins directory, none of the incoming calls will be accepted by the IVR.


Make sure the controller is configured correctly and enabled. This can easily be tested by making some calls using the test tool provided by the capi manufacturer (e.g. Xcapi Test Tool).


The IVR can detect many problems (e.g. inconsistent configuration) and will describe them in the IVR logfile. So make sure to read the IVR log and look for lines starting with ” E> ”

A FACE to Remember

By remembering this short word, you can quickly diagnose and fix most common IVR problems yourself!

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