Maintaining Hardware Components
The following guidelines apply specifically to fiber-optic cable:
When you unplug a fiber-opticcable from a PIC, always place a rubber safety
plug over the transceiveron the PIC faceplate and on the end of the cable.
Anchor fiber-optic cable to avoidstress on the connectors. When attaching
fiber to a PIC, be sure to secure the fiber so it is not supporting its own weight
as it hangs to thefloor. Never let fiber-optic cable hang free from the connector.
Avoidbending fiber-optic cable beyond its bend radius. An arc smaller than
a few inches can damage the cable and cause prob lems that are difficult to
diagnose.
Frequent plugging and unplugging of fiber-opticcable into and out of optical
instruments, such as ATM or SONET/SDH analyzers, can cause damageto
the instruments that is expensiveto repair. Instead, attach a short fiber
extension to the opticalequipment. Any wear and tear due to frequent
plugging and unplugging is then absorbedby the short fiber extension, which
is easy and inexpensive to replace.
Keep fiber-optic cable connections clean. Small micro-deposits of oil and dust
in the canal of the transceiveror cable connector could cause loss of light,
reducing signal powerand possibly causing intermittent problems with the
optical connection.
To cleanthe transceivers, use an appropriate fiber-cleaning device,such as
RIFOCS Fiber Optic AdaptorCleaning Wands (part number 946). Follow the
directions for the cleaningkit you use.
After you have cleaned the transceiver on the fiber-optic PIC, make sure that
the connector tip of the fiber-optic cable is clean. Use only an approved
alcohol-free fiber-opticcable cleaning kit, such as the Opptex Cletop-S® Fiber
Cleaner. Followthe directions for the cleaning kit you use.
Maintaining the PCGs
The router has twoPacket Forwarding Engine ClockGenerators (PCGs) installed in
the slots labeled PCG 0 and PCG 1 on the rear of the chassis, as shown inFigure 3.
To maintain the PCGs,perform the following procedures regularly:
Check the LEDs on the PCG faceplates. The green LED labeledOK light s
steadily when the PCG is functioning normally. The blue LED labeled
MASTER lights steadily on the master PCG. Formore information, see “PCG
Components” on page 19.
Issue the CLI show chassis environment pcg command to check the status of
the PCGs. As shown in th e sample output, the master PCG is designated
Online - Master clock and the standby PCG Online - Standby:
user@host> show chassis environment pcg
PCG 0 status:
Maintaining Packet ForwardingEngine Components 135