Local Dual-Sided Loopback; Local Customer Loopback; Local Network Loopback; Figure 5-64. Local Dual-Sided Loopback - ADTRAN Total Access 1240 Installation And Maintenance Practice

Section 5, User Interface - Menu Descriptions

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.
LTU NTU

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.
TX
LTU NTU
AIS

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.
LTU NTU
TX AIS

Figure 5-66. Local Network Loopback

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