METRObility Optical Systems R111-1T - Manual (Page 11)

Radiance 10Mbps Single Interface Line Cards 11
Link Loss Carry Forward (LLCF) *
The Radiance 10Mbps single interface line cards incorporate an LLCF function
for troubleshooting a remote connection. When LLCF is enabled, the FL and TP
ports do not transmit a link signal until they receive a link signal from the
opposite port.
The diagram below shows a typical network configuration with a good link
status using Radiance line cards for remote connectivity. Note that LLCF is
enabled as indicated in the diagram.
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Radiance
Line Card
Radiance
Line Card
LED lit = established link LED unlit = no link
LLCF is ON LLCF is ON
TP TP FL
Remote
Cable
If the connection breaks, the line card carries that link loss forward to the
switch/hub which generates a trap to the management station. The administrator
can then determine the source of the problem.
Link Loss Carried Forward Link Loss Carried Forward
LED lit = established link LED unlit = no link
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Radiance
Line Card
Radiance
Line Card
LLCF is ON LLCF is ON
TP TP Broken
FL Remote
Cable
Link Loss Carried Forward
LED lit = established link LED unlit = no link
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Radiance
Line Card
Radiance
Line Card
LLCF is ON LLCF is ON
TP Broken
TP
Cable
FL
Remote
Cable
Important: When connecting a Radiance line card with LLCF enabled to an auto-
negotiating device, force both sides of the configuration to 10Mbps and either full
or half duplex. This allows the card to immediately see link pulses and start passing
data.
* Line cards are shipped with LLCF disabled (OFF).