Verilink M1-3 (880-503136-001) Product Manual - Manual (Page 66)

M1-3 Diagnostics
5-10 Verilink M1-3 User Manual
down code (001) for the same time period. In ESF mode, the line
loopback is also activated and deactivated by sending bit-oriented
messages through the ESF Facility Data Link.
Figure 5-16 T1 Line Loopback
T1 FEAC Far End
Loopback
When a T1 far-end line loopback is activated, the data received
from the network is transmitted back toward the near end. The
looped signal passes through the M1-3 repeater so that the line
loopback can be used to test the circuit from the near-end M1-3 or
telephone company (
Figure 5-17 ).
Figure 5-17 T1 Far End Loopback
The M1-3 sends the network signal or AIS to the equipment,
depending on how the M1-3 is configured.
To activate a far -end line loopback for a T1, do the following:
1. From the M1-3 Loopback Selection Menu, type “F” and press
E NTER then type “A” ( Figure 5-14 ).
M1-3 M1-3
Near End
Far End
1 of 28 T1’s
T3
M1-3 M1-3
Near End
Far End
1 of 28 T1’s
T3