I am trying to configure a DID for a particular extension. We have the translation rules in place and I have no other issues with several other phones. However, this one particular extension and number constantly gives me the busy signal when trying to reach from outside. I am not a voice expert and I am just learning voice. The system was configured prior to my employment so I have reviewed and tried to understand what is going on with it, but I cannot seem to figure out why this one extension is not working. I am sure it is something simple that I am overlooking. Any help would be appreciated. I can provide the config details as requested.
If you are allowed to, please send the output of debug "voip ccapi inout" and let us know the calling number, called number and time stamp. This will allow us to see if the call is failing on your equipment or on the service provider's equipment.