ADTRAN Total Access 1240 - Manual (Page 125)

Section 5, User Interface - Menu Descriptions
61179605L5-5B 5-85
Local Dual-Sided Loopback
The local dual-sided loopback provides a bidirectional loopback at the Line Termination Unit
(LTU), as shown in
Figure 5-64 .
Figure 5-64. Local Dual-Sided Loopback
Local Customer Loopback
The local customer loopback provides a loopback at the LTU in the customer direction, as
shown in
Figure 5-65 . An Alarm Indication Signal (AIS) is injected into the network side.
Figure 5-65. Local Customer Loopback
Local Network Loopback
The local network loopback provides a loopback at the LTU in the network direction, as shown
in
Figure 5-66 . An AIS signal is injected into the customer side.
Figure 5-66. Local Network Loopback
LTU NTU
LTU TX
AIS
NTU
LTU
TX AIS
NTU