Figure 5-61. Ds3 Line Loopback Test; Figure 5-62. Ds3 Digital Loopback Test; Digital Loopback - ADTRAN MX2820 System Manual

DSX-3
LIU

Digital Loopback

A DS3 Digital Loopback test loops the entire DS3 signal back to the local loop side. The end
effect of this test is a loopback of all T1/E1 signals after being fully multiplexed and demulti-
plexed to and from a DS3 signal. The incoming DS3 data is ignored, and the outgoing DS3
stream is substituted in its place prior to exiting the DS3 framer.
illustration of this test.
DSX-3
LIU
61186003L1-1D
F F
R R
M23 M12/G.747
D D
A A
S MUX/ S MUX/DMUX
M M
3 2
DMUX
E E
R R

Figure 5-61. DS3 Line Loopback Test

F F
R R
M23 M12/G.747
D D
A A
MUX/
S S MUX/DMUX
M M
3 DMUX 2
E E
R R

Figure 5-62. DS3 Digital Loopback Test

Section 5, User Interface Guide - UIG-530, M13 Loopbacks
CODEC
(1 of 28)
(1 OF 7)
CODEC
(28 of 28)
CODEC
(1 of 28)
(1 OF 7)
CODEC
(28 of 28)
T1/E1 LIU
(1 of 28)
T1/E1 LIU
(28 of 28)
Figure 5-62 provides an
T1/E1 LIU
(1 of 28)
T1/E1 LIU
(28 of 28)
5-93