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DS1 I/O Front Module
Plexus 9000 Planning and Engineering Guide
Issue 4, April 23, 2004
Section 130-120-400
5-118
Telica,
Inc.
5.9.3.9 DS-1
Loopback
DS-1 loopbacks can be used as diagnostics to test line integrity. There are
two types of loopbacks, line and payload. A line loopback loops the entire
DS-1 signal. Loopbacks can occur at the near or far end facility. The
Plexus 9000 can respond to as well as initiate loopbacks. A payload
loopback loops the DS-1, but the framing bit is removed. A framing bit is
reinserted before it is transmitted. Refer to
for line
loopbacks of the near-end and to
for far-end loopbacks.
for payload loopbacks of the near-end and to
of the far-end. Loopbacks are initiated or cleared using TL1
commands.
P161-AA
01-06-03
Telica
Framer
Framer
Remote
Near-end Facility Line
Figure 5.9-3. DS1 Line Loopbacks (1.544 Mb/s) at the Near-end
P163-AA
01-06-03
Telica
Framer
Framer
Remote
Far-end Facility Line
Figure 5.9-4. DS1 Line Loopbacks (1.544 Mb/s) at the Far-end