User guide

16 User Guide
Copper Loss Carry Forward (CLCF)
The R153-1S copper-to-fiber card incorporates CLCF for identifying a lost
copper connection. When CLCF is enabled
*
, the fiber port’s transmitter shuts
down if the copper port stops receiving link pulses. The copper port, however,
continually transmits link signals regardless of whether or not the fiber port
receives link signals.
The diagram below shows a typical network configuration with good link status
using two R153-1S line cards for remote connectivity. Note that CLCF is
enabled as indicated.
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Gigabit
Line Card
LED lit = established link LED unlit = no link
Fiber
Cable
Gigabit
Line Card
Copper
Cable
Copper
Cable
CLCF is ON CLCF is ON
If a copper connection breaks, the line card will carry that link loss forward.
Copper Loss Carried Forward
LED lit = established link LED unlit = no link
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Broken
Copper
Cable
Gigabit
Line Card
Gigabit
Line Card
CLCF is ON
CLCF is ON
Loss of link at the fiber port is not propagated, as shown below.
LED lit = established link LED unlit = no link
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Broken
Fiber
Cable
Gigabit
Line Card
LLR2 is OFF
Gigabit
Line Card
*Units are shipped with CLCF disabled (DOWN). CLCF is not applicable to the R153-SS.