Here you go:
Level 1 reset erases all customer-specific data and restores the default configuration for all
components. This reset leaves the software components untouched. That is, the system has the
latest release and patch level of the software installed. Only the system and user configuration
data is erased and replaced with default values. No Ethernet connectivity to the system occurs
during this operation.
Level 2 reset erases all customer and system configuration data and all software releases and
patches. This reset re-installs the original factory configuration settings. Level 2 reset also
resets the router firmware to what was shipped from the factory. No Ethernet connectivity to
the system occurs during this operation.
The actual SYS ID does NOT get changed using either method, however, it sounds like you did a Level 2 if keycodes and all are gone. Level 1 will erase the customer database, but Level 2 makes the system as it came from the factory. The keycodes that were previously installed will work IF the s\w release is the same as it is after the Level 2 Reset. That is why it always important to install the Factory Image patch AFTER ANY s\w release update. and THEN backup the system. ***NOTE***- When backing up the system, you will be prompted where to save the file on your PC. When you save the file , do a "Save As" and save the backup file as something you will recognize such as using the date AND put a ".tar" extension at the end of the file name. Example: "BU051114.tar". The reason to do this is if you save in a .tar format, you can go INTO the "Keycode.tar" file and retrieve the keycodes for the system.
This is not a publicized feature, but trust me, that is the way to do it so you can get your keycodes if needed.
Just an FYI....I was at Nortel for 18 years. 5 1/2 in Norstar ITAS as the Staff Engineer. I was the last person to see the trouble before it went tot the Design Engineers. I was involved with BCM when it was parts on a table in a lab and code named "Conan" right before the product was released as Enterprise Edge. I supported BCM for the North American and Regional Sales Engineers in Pre-Sales Engineer role. Then one day I got a phone call from Nortel telling me "Have a nice life". Now my focus is on the E-Metrotel UCx platforms. The ONLY reason I am telling the "credential stuff" is to validate what I am posting.
Hope this helps going forward.....
Stocking Distributor for E-Metrotel