It sounds like this ATA has been been set with the UI password which prevents factory resets etc. Have a look;
Starting with v2.16, Cisco introduced a setting that would permit the device to be locked such that it is impossible to recover or reset the password under any circumstances. The rumor is that a certain large VoIP long distance company demanded that this be added so that their customers would stop selling the ATA-186 units that came with their inexpensive introductory offer. This "locking" setting is optional, so it is not the case that all v2.16 units are unusable, just that it is possible that they are unusable
Password Protection for Factory Reset and Local Upgrade
Factory reset and local upgrade using the voice configuration menu can now be protected with the User Interface (UI) UI password. If the UI password (UIPassword parameter) is enabled, the Cisco ATA prompts the user for the password before a factory reset or upgrade is allowed.
SIP traces provide key information in troubleshooting SIP Trunks, SIP
endpoints and other SIP related issues. Even though these traces are in
clear text, these texts can be gibberish unless you understand fully
what they mean. This document attempts to br...
Please find the attached HTML document, download and open it on your PC.
This provides an easy to use form where you simply answer a few
questions and it will render the proper jabber-config.xml file for you
to copy/paste. There is built in logic to verif...
[toc:faq]CUCM Database Replication is an area in which Cisco customers
and partners have asked for more in-depth training in being able to
properly assess a replication problem and potentially resolve an issue
without involving TAC. This document discusse...