User guide

Radiance 1Gbps Interface Line Cards with SFP Optics 7
Link Loss Return (LLR) Switch
The Radiance 1Gbps line card offers Link Loss Return functionality as
an aid in troubleshooting remote fiber connections. When LLR is
enabled on a fiber port, loss of link by the port’s receiver disables its
own transmitter from sending out link pulses. LLR is enabled indepen-
dently on each fiber port and is not applicable to the copper port.
LLR2 enables/disables Link Loss Return on Port 2. LLR1 enables/
disables the function on Port 1 of the R153-SS. To enable Link Loss
Return, set the switch to the UP position. Set the switch DOWN to
disable the LLR. The unit is shipped with LLR disabled.
For more information, refer to Link Loss Return.
Link Loss Carry Forward (LLCF) Switch
On the R153-SS, Link Loss Carry Forward is provided as an additional
aid in troubleshooting remote connections. If the card loses link on one
of its receivers, LLCF will inhibit the transmission of link pulses out
the opposite port.
For example, if LLCF is enabled and the line card fails to detect link on
Port 2, the card will not transmit link pulses from Port 1. In doing this,
LLCF provides a way to extend the link loss indication beyond a single
segment.
LLCF is enabled when the LLCF switch is in the UP position. The
R153-SS is shipped with LLCF disabled. For more information, refer to
Link Loss Carry Forward in the User Guide section. LLCF is not
applicable to the R153-1S.
Copper Loss Carry Forward (CLCF) Switch
The R153-1S provides Copper Loss Carry Forward to assist in identify-
ing a lost copper link. When CLCF is enabled and the card loses link on
its copper port, CLCF stops the fiber port from transmitting link pulses.
CLCF has no effect on the copper port, which continually transmits
pulses, even if the fiber port loses link.
CLCF is enabled when the CLCF switch is in the UP position. The
card is shipped with CLCF disabled. For more information, refer to
Copper Loss Carry Forward in the User Guide section.