Radiance 10/100 Mbps Services Line Card
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Default Hardware Switch Settings
All hardware switches can be overridden through software commands.
The card’s default settings are listed below.
Auto-Negotiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Enabled (UP)
Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Mbps (UP)
Duplex. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Full (UP)
Link Loss Return (LLR)
The fiber optic port (Port 2) of the R821 services line card has been
designed with LLR
6
to assist in troubleshooting.
When LLR is enabled, the fiber port’s transmitter shuts down if its
receiver fails to detect a valid receive link. The transmitter will remain off
except to periodically transmit heartbeat pulses. Every second, the trans-
mitter will attempt to establish link for 100 ms.
The diagram below shows a typical network configuration with good link
status using a services line card for remote connectivity. LLR is enabled
on Port 2.
If one of the fiber cables is bad (as shown in the diagram box below), the
R821 will return a no link condition to its link partner. This helps the
network administrator in determining the source of the loss.
6.Link Loss Return is disabled by default.
PC
Switch/Hub
w/SNMP
Customer
Site
Fiber
Cable
LED lit = established link
LED unlit = no link
LLR2 is ON
Services
Line Card
PC
Switch/Hub
w/SNMP
Customer
Site
Link Loss Returned
LED lit = established link
LED unlit = no link
Broken
Fiber
Conductor
LLR2 is ON
Services
Line Card