There was an experience I had with a C class where an internal counter related to voicemail his a threshhold and locked up. I talked with a female tech there and she discovered the problem and reset a counter in the factory programming. I iwsh I remembered her name at ESI. She was a tech support person. She had to get into the phone system herself to correct it.

www.hospitalityphones.com, .net and .org are for sale at a reasonable price or offer.
I am now Retired and no longer need these URL's