ADTRAN 1200291L1 Switch User Manual


 
Chapter 6. Diagnostics
61200659L1-1 MX2800 STS-1 User Manual 6-9
Figure 6-11. Line Network Test
Analog Loopback
An
A
NALOG
L
OOPBACK
loops the entire STS-1 back to the local
loop side. The end effect of this test is a loopback of all VT/Ports
after passing through the STS-1 mapper and the LIU. The incoming
STS-1 data is ignored and the outgoing STS-1 stream is looped
back into the “AGC/Receive Equalizer Block” in the LIU. This test
is illustrated in Figure 6-12.
Figure 6-12. Analog Loopback
STS-1
MAPPER
T1/E1 LIU
(1 of 28)
T1/E1 LIU
(28 of 28)
STS-1
LIU
CODEC
(1 of 28)
CODEC
(28 of 28)
STS-1
MAPPER
T1/E1 LIU
(1 of 28)
T1/E1 LIU
(28 of 28)
STS-1
LIU
CODEC
(1 of 28)
CODEC
(28 of 28)