Dell PowerConnect J-8208, Hardware Manual

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NOTE: We recommend that you maintain N +1 or N+N power supplies in your
switch at all times. Replace failed power supplies immediately to prevent
unexpected failures.
Power management raises a minor alarm if the number of online power
supplies in your switch is less than the number required to maintain the
configured N+1 or N+N power redundancy. If the problem is not corrected in
5 minutes, a major alarm is issued.
Power management raises a major alarm if the number of online power
supplies in your switch is less than N power supplies. Power management
provides power to line cards in priority order until power is exhausted. The
remaining line cards are powered off.
If a new line card is installed in an operational switch, power management
does not power on the line card if the increased power demand exceeds the
total available power, including redundant power. If redundant power is used
to power on the line card, a minor alarm is raised, which becomes a major
alarm in 5 minutes if the condition is not corrected.
Related
Documentation
AC Power Supply in a J-EX8200 Switch on page 34
•
•
For more information about power management on the switch, see the Dell
PowerConnect J-Series Ethernet Switch Complete Software Guide for Junos OS at
http://www.support.dell.com/manuals .
Calculating the J-EX8200 Switch Fiber-Optic Cable Power Budget
Calculate the link's power budget when planning fiber-optic cable layout and distances
to ensure that fiber-optic connections have sufficient power for correct operation. The
power budget is the maximum amount of power the link can transmit. When you calculate
the power budget, you use a worst-case analysis to provide a margin of error, even though
all the parts of an actual system do not operate at the worst-case levels.
To calculate the worst-case estimate for fiber-optic cable power budget (
P
B
) for the
link:
1.
Determine values for the link's minimum transmitter power (
P
T
) and minimum receiver
sensitivity ( P
R
). For example, here, ( P
T
) and ( P
R
) are measured in decibels, and
decibels are referred to one milliwatt (dBm).
P
T
= –15 dBm
P
R
= –28 dBm
NOTE: See the specifications for your transmitter and receiver to find the
minimum transmitter power and minimum receiver sensitivity.
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Dell PowerConnect J-Series J-EX8208 Ethernet Switch Hardware Guide