I think we finally found a fix! We have been stable now for over a month.  We were given the following action plan from TAC:  Action Plan Please go to phone >> device >> ata devicw >> search for this parameter and disable line 2 ; click on save and t...

We ordered 13 ATA 191's and are having this issue. They stay registered for 20 minutes or so, then drop registration. The IP, and Registration status dont appear in cucm (ver.11.5 SU4).  Tried to upload latest firmware, still no luck. Anybody with a ...