User guide

“twister” 2131 Media Converter 13
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Metrobility
2131
Metrobility
2131
Remote
up to 15km
LED lit = established link LED unlit = no link
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Metrobility
2131
Metrobility
2131
Broken
Remote
Cable
Trap generated Trap generated
Link Loss Carried
LED lit = established link LED unlit = no link
Link Loss Carry Forward (LLCF)
The Metrobility 2131 has been designed with a LLCF function for troubleshooting a
remote connection. The unit is shipped with the LLCF disabled.
When LLCF is enabled, the fiber optic ports as well as the twisted-pair ports on the
2131 media converter do not transmit a link signal until they receive a link signal from
the opposite port. For example, if LLCF is enabled and two 2131 media converters are
connected via a fiber cable with nothing else connected to them, the link (LK) LEDs do
not illuminate. When a valid link is established at the twisted-pair port, a complete
connection is accomplished.
The diagram below shows a typical network configuration using 2131 media
converters for remote connectivity:
If the fiber connection breaks, or the remote device fails, the 2131 media converter
carries that link loss all the way to the switch/hub which generates a trap to the
management station. The administrator can then look at the media converter to
determine the source of the loss.
IMPORTANT: When connecting a 2131 media converter with LLCF enabled to an
auto-negotiating device, force both sides of the configuration to 100Mbps full or half
duplex. This allows the interface media converter to immediately see link pulses and
start passing data.