Black Box MT1000A-13-R3, Quick Start Manual

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MT1000A Installation and Operation Manual Chapter 5 Testing and Diagnostics
Diagnostic Tests 5-5
Local Loopbacks in the MT1000A
You can set two types of local loopback connections in the MT1000A unit:
• T1 local, which is set for each T1 interface separately from a terminal.
•
Fiber optic link local, which can be set from a terminal.
T1 Local Loopback in the MT1000A
The T1 local loopback returns the T1 transmit signal to the output of the receive
path. Simultaneously, an unframed all-ones signal is sent to the MUX.
Figure 5-1
shows the T1 local loopback connection.
This test checks the operation of the connections to the equipment attached to the
local tributary interfaces.
Figure 5-1 T1 Local Loopback in the MT1000A