Loopbacks
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Overview
Metropolis
®
DMXplore supports facility and terminal electronic
loopbacks.
Loopback Commands
Loopbacks may be implemented using the
opr-lpbk-rr
command,
released using the
rls-lpbk-rr
command, retrieved using the
rtrv-lpbk-rr
command, or can be provisioned using the WaveStar
®
CIT graphical display.
From the WaveStar
®
CIT System View, select
Fault
→
Loopback
and then select the circuit pack and the desired port. Choose either
Facility or Terminal for Loopback Type and click on
Operate
or
Release
.
Active port loopbacks are indicated by a continuously lighted
MN/ABN
LED on the SYSCTL circuit pack. Clicking on the
Alarm List
button
from the WaveStar
®
CIT System View and entering the commands
rtrv-lpbk-rr
and
rtrv-cond
return reports that indicate that
loopbacks are present.
Facility loopbacks
A Facility loopback connects the incoming received signal to the
transmitter in the return direction. Electrical signals are looped back
intact, including BPVs. Optical signals are looped back after the
optical to electrical conversion.
Facility loopbacks are supported on low-speed DS1 and DS3 electrical
interfaces, and high-speed OC-12 interfaces.
The following figure shows a facility loopback used in a test
arrangement with an external test set.
Figure 4-2 Facility loopback example
Rx
Rx
Tx
Tx
Cross-
Connect
Cross-
Connect
Circuit Pack
Circuit Pack
AIS-P
Facility Loopback
Looped
Port/Line
MA-DMX-322
External
Test
Set
Maintenance overview
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365-372-333 R2.1
Issue 4, June 2005
Lucent Technologies
4 - 2 1