Digital Loopback; Figure 6-13. Digital Loopback - ADTRAN 1200287L1 User Manual

Chapter 6. Diagnostics

Digital Loopback

A
side. The end effect of this test is a loopback of all VT/Ports after
passing through the STS-1 mapper and partially through the LIU.
The incoming STS-1 data is ignored and the outgoing STS-1 stream
is substituted in its place just prior to entering the STS-1 encoder
block of the LIU. This data will be processed through the "Transmit
Clock Duty Cycle Adjust" PLL and the "HDB3/B3ZS Encoder"
block. At this point, the data will be looped back to the "HDB3/
B3ZS Encoder" block. This test is illustrated in Figure 6-13.
STS-1
6-10
D L loops the entire STS-1 back to the local loop
IGITAL OOPBACK
STS-1
MAPPER
LIU
MX2800 STS-1 User Manual
CODEC T1/E1 LIU
(1 of 28) (1 of 28)
CODEC T1/E1 LIU
(28 of 28)
(28 of 28)

Figure 6-13. Digital Loopback

61200659L1-1