ADTRAN TOTAL ACCESS MX2800, User Manual, Page: 86 / 142

Chapter 6. Diagnostics
6-2 MX2800 User Manual 61200290L1-1
T1/E1 LOOPBACKS
After you select the number that corresponds with the line you
want to test, the menu in Figure 6-2 appears. The sections following
the figure provide descriptions and illustrations of the testing
options. Select
1-D
ATA
M
ODE
to end a test in progress.
Figure 6-2. T1/E1 Diagnostics Menu
Tributary
A T
RIBUTARY
loopback loops the selected T1/E1 back to the
network (DS3). The T1/E1 is de-multiplexed through the M23 and
M12/G.747 de-multiplexers, looped back, and multiplexed back up
through the M12/G.747 and M23 multiplexers. During this
loopback, all network receive data is passed to the DSX-1/E1
transmitters, but all data received by the DSX-1/E1 loop side is
ignored and substituted with the network data. See Figure 6-3 on
page 6-3 for an illustration of this test.