ADTRAN 1200218L1, User Manual

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Chapter 6. Diagnostics
61200663L1-1 OSU 300 User Manual 6-9
#x Local Loopback
During this test, all information from the network side (DS3) for the
selected DSX-1 interface is looped back towards the network. This
test is similar to the framer loopback test (described in the previous
paragraph), with the exception that this test penetrates the circuitry
deeper into the Quad DSX-1 interface card. See Figure 6-12 for an
illustration of this test.
Figure 6-12. T1 Local Loopback Test
#x Line Loopback
During this test, all information on the selected DSX-1 interface,
including framing, is looped back towards the DTE. See Figure 6-13
for an illustration of this test.
Figure 6-13. Line Loopback Test
OSU 300
T3 DSX-1
Quad DSX-1
DS3 MUX
F
ramer/F
or
matter
Jitter Atten
uator
Elastic Store
OSU 300
T3 DSX-1
Quad DSX-1
DS3 MUX
F
ramer/F
or
matter
Jitter Atten
uator
Elastic Store