ADTRAN 4200659L1 - Manual (Page 133)

Chapter 6. Diagnostics
61200659L1-1 MX2800 STS-1 User Manual 6-11
Metallic Diagnostics
A M ETALLIC D IAGNOSTIC loopback test 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 being fully multiplexed and de-multiplexed to and
from the STS-1 and passed through both directions of the LIU.
During this test, the incoming STS-1 is disconnected from the
STS-1 receiver and the outgoing STS-1 signal is substituted in its
place. See Figure 6-14 for an illustration of this test.
Figure 6-14. Metallic Diagnostics Loopback Test
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)