Nortel 5100 Series Release 2.3.3, User'S Manual And Command Reference, Page: 216 / 430

Nortel Switched Firewall 2.3.3 User’s Guide and Command Reference
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Applications
213455-L, October 2005
Uninterruptible Power Supply
Nortel Switched Firewall (NSF) 2.3.3 supports the American Power Corporation (APC) Unin-
terruptible Power Supply (UPS) daemon. When you use NSF 2.3.3 you can monitor power
with a battery meter.
Using the APC UPS daemon, your Firewall can function during power outages. NSF 2.3.3 sup-
ports UPS with the following devices:
„ USB port
„ SNMP through Ethernet
In a power failure, the APC UPS daemon informs the Firewall about the power failure and that
a shutdown may occur. If power is not restored, a system shutdown follows when one of the
following occurs:
„ the battery is exhausted
„ a timeout (in seconds) expires
„ a runtime expires based on internal APC calculations
Sometimes power returns during the system shutdown process. Most UPS devices cannot shut
down when power is present; this leads to deadlock—the system halts until you restart it.
However, the NSF 2.3.3 UPS daemon not only shuts down the UPS, but checks the power line
just before the end of the halt script. If the UPS daemon detects that power is restored, it
reboots the Firewall. Also, the detection of a low battery signal from the UPS can be used to
immediately shut down the Firewall.
Configuring UPS support
To configure the Firewall to support UPS, you need to specify the UPS mode. Depending on
the UPS mode, you are prompted to specify other parameters.