General Troubleshooting Tips - 3Com CoreBuilder 5000 User Manual

5-2 T
ROUBLESHOOTING
General
Troubleshooting
Tips
Improper configuration of a module may cause unexpected results. The
LEDs on the module provide a good indication of errors.
Troubleshooting using the port and module LEDs is described later in
this chapter. If you experience a problem with your module, you should
also verify that:
All cabling and connection hardware meets the specifications
outlined in Chapter 2
Any attaching device or station is set to the same ring speed as the
network that the port (port-switching media modules) or module
(module-switching media modules) is assigned to.
Only STP cabling, or Level 4 or 5 UTP cabling, used on the copper
Ring-In/Ring-Out ports
Fiber cabling connects properly (that is, transmit always connects
directly to receive)
Fiber Ring-In port connects to a fiber Ring-Out port
Fiber ports on the module are used to connect only to other
CoreBuilder 5000 devices, ONline devices, or to an IBM 8230
Controlled Access Unit (CAU)
Jitter Attenuator Card is attached to Ring-In/Ring-Out ports that
connect to non-CoreBuilder 5000 equipment
Trunk compatibility mode settings on 3Com devices are set as
described in Chapter 4
of this guide
of this guide