Loopbacks overview – Black Box COMPACT T1 MT850A User Manual
Page 535

Compact T1 - Release 6.1
B-7
Diagnostices & Troubleshooting
Loopbacks Overview
Loopbacks Overview
A loopback test is a diagnostic procedure in which a signal is transmitted and returned
to the sending device after passing through all or a portion of a network or circuit. The
returned signal is compared with the transmitted signal in order to evaluate the integrity
of the equipment or transmission path. The following are the Loopbacks available.
T1 Loopbacks
OCU-DP Loopbacks
l
Manual OCU Loopback
l
Manual CSU Loopback
l
OCU Latching Loopback
l
CSU Latching Loopback
l
DSU Latching Loopback
l
DSU Non-Latching Loopback
l
CSU Non-Latching Loopback
l
OCU Non-Latching Loopback
l
OCU Manual Loopback
l
CSU Manual Loopback
Card
Line
Equipment
Payload
CSU
Controller T1
Yes
No
Yes
Yes
Quad T1
Yes
Yes
Yes
Yes
V.35 T1
Yes
Yes
No
No
V.54 T1
Yes
Yes
No
No
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