Nortel Networks 2004 - Manual (Page 123)

Additional features
123
Media Gateway 1000B
The Media Gateway 1000B (MG 1000B) telephone can operate in Normal
or Local mode.
Normal Mode
The telephone registers with the Main Office and receives telephone
services from the Main Office. At any time during Normal Mode, you can
check local mode functionality (make and receive calls) by enabling Local
Mode and returning to Normal Mode. After testing, you can return to
Normal Mode by using the Resume Normal Mode command or by waiting
for ten minutes.
Local Mode
If the WAN connection goes down, the IP Phone loses communication
with the Main Office TPS. It then registers with the MG 1000B and
receives telephone services from the MG 1000B. Features such as
Personal Directory, Redial List, and Callers List are not available when
operating in Local Mode. When in Local Mode, the telephone displays
“LOCAL MODE”.