System information

Troubleshooting Hardware and Booting Problems 3-39
LightStream 2020 Startup
Interface module
problems
The packet line card is compatible with the following access cards:
— FDDI access card
— Ethernet access card
— Fiber Ethernet access card
— T1 circuit emulation access card
— E1 circuit emulation access card
The NP is compatible with the following access card:
—NPAC
• If an FDDI
7
module does not pass traffic, make sure the FDDI cables for
each port are attached to the proper connectors.
• If you are bringing up a low-speed module, make sure the interface
jumpers on the access card are set to match the physical interfaces marked
on the fantails (V.35, X.21 or RS-449).
• If you are bringing up an E1 circuit emulation module, make sure the
interface jumpers on the access card are set properly.
If you are having signal quality problems with a physical interface on an
access card, check the following:
• Make sure that cables are within the specifications of your media type.
• Make sure that connectors are not damaged. Check optical connectors for
dirt or scratches on the optical surface. For electrical connectors, check
that pins are not bent, broken, or loose.
Interface module
problems
If you are experiencing any of the following symptoms, you might need to
replace the line card or its access card:
• POST fails (the FLT LED stays lit and the POST indicates a problem).
• A card fails even when moved to another slot. (When you move a line
card, be sure to pair it with an appropriate access card. When you move an
access card, pair it with an appropriate line card.)
• Hardware diagnostics fail.
• The line card fails to load.
• The line card hangs repeatedly.
• The line card or access card cannot be fully inserted into its slot. This
probably indicates damage to the connectors on either the card or the
midplane. Inspect all the connectors and replace the card or the midplane
if you find damage.
• Two or more ports are passing no traffic, dropping many cells, or flapping.
If only one port has symptoms, there is probably a problem with the line,
the external DSU/CSU if one is present, the access card, or the remote
device. Use the looping tests described in the LightStream 2020 Network
Operations Guide to help isolate the problem.
Possible Problem Solution