Maintaining M120 PICs and PIC Cables

Purpose

For optimum router performance, verify the condition of the PICs and PIC cables.

Action

On a regular basis:

• Check the LEDs on PIC faceplates. Most PIC faceplates have an LED labeled STATUS. Some PICs have additional LEDs, often one per port. The meaning of the LED states differs for various PICs. For more information, see the M120 PIC Guide. If the FPC that houses the PIC detects a PIC failure, the FPC generates an alarm message to be sent to the Routing Engine.
• Issue the CLI show chassis fpc pic-status command. The PIC slots in an FPC are numbered from 0 through 3, top to bottom:
  
  

  user@host> show chassis fpc pic-status

  Slot 2   Online       M120 FPC Type 1 
    PIC 2  Present      1x G/E, 1000 BASE-SX- Not Supported
    PIC 3  Online       1x Tunnel
  Slot 3   Online       M120 FPC Type 2 
    PIC 0  Online       4x OC-3 SONET, SMIR
    PIC 1  Present      2x G/E, 1000 BASE-SX- Not Supported
    PIC 2  Online       4x G/E SFP, 1000 BASE
    PIC 3  Present      1x OC-48 SONET, SMSR- Not Supported
  Slot 4   Online       M120 FPC Type 3 
  Slot 5   Online       M120 FPC Type 1 
    PIC 0  Online       1x G/E SFP, 1000 BASE
    PIC 2  Online       4x CHDS3 IQ
   

  For further description of the output from the command, see the Junos OS System Basics and Services Command Reference.

• Use the cable management system (shown in Cable Management System) to support cables and prevent cables from dislodging or developing stress points.
• Place excess cable out of the way in the cable management system. Do not allow fastened loops of cable to dangle from the connector or cable management system, because this stresses the cable at the fastening point. Putting fasteners on the loops helps to maintain their shape.
• Keep the cable connections clean and free of dust and other particles, which can cause drops in the received power level. Always inspect cables and clean them if necessary before connecting an interface.
• Label both ends of PIC cables to identify them.

The following guidelines apply specifically to fiber-optic cable:

• When you unplug a fiber-optic cable from a PIC, always place a rubber safety plug over the transceiver on the PIC faceplate and on the end of the cable.
• Anchor fiber-optic cable to avoid stress 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 the floor. Never let fiber-optic cable hang free from the connector.
• Avoid bending fiber-optic cable beyond its bend radius. An arc smaller than a few inches can damage the cable and cause problems that are difficult to diagnose.
• Frequent plugging and unplugging of fiber-optic cable into and out of optical instruments, such as ATM or SONET/SDH analyzers, can cause damage to the instruments that is expensive to repair. Instead, attach a short fiber extension to the optical equipment. Any wear and tear due to frequent plugging and unplugging is then absorbed by 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 transceiver or cable connector could cause loss of light, reducing signal power and possibly causing intermittent problems with the optical connection.

  To clean the transceivers, use an appropriate fiber-cleaning device, such as RIFOCS Fiber Optic Adaptor Cleaning Wands (part number 946). Follow the directions for the cleaning kit 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-optic cable cleaning kit, such as the Opptex Cletop-S® Fiber Cleaner. Follow the directions for the cleaning kit you use.