Radiance SONET Single Interface Line Cards 11
Link Loss Carry Forward (LLCF)
The Radiance SONET single interface line card incorporates LLCF for trouble-
shooting a remote connection. With LLCF, the ports do not transmit a signal
until they receive a signal from the opposite port. For example, if a line card
loses link on Port 2, the card will not transmit link pulses out of Port 1.
The diagram below shows a typical network configuration with good link status
using SONET line cards for remote connectivity.
If a connection breaks, the line cards carriy that link loss forward to the switch/
hub which generates a trap to the management station. The network administra-
tor can then determine the source of the problem.
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
LED lit = established link
LED unlit = no link
Remote
Cable
SONET
Line Card
SONET
Line Card
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
Broken
Remote
Cable
SONET
Line Card
SONET
Line Card
Link Loss Carried Forward
LED lit = established link
LED unlit = no link
Management
Station
Management
Station
Switch/Hub
w/SNMP
Switch/Hub
w/SNMP
Broken
Cable
Remote
Cable
SONET
Line Card
SONET
Line Card
