5. Testing
8799-A2-GB20-10
April 2003
5-3
DSL Line Loopback
A DSL Line Loopback (LLB) loops the received signal on the DSL port back to the
DSL port without change. If the DSL port is configured in a DSL cross connection,
the corresponding G.703 time slots will be filled with ones. On ports in Bypass
mode or in a DS1 cross connection, an Alarm Indication Signal (AIS) is sent on the
G.703 port.
Procedure
To run a DSL Line Loopback:
1. Position the cursor at the Start command next to DSL Loopback on the DSL &
G.703 Tests screen.
2. Press Enter.
The Start command is changed to Stop. Status is changed to Active.
3. To manually stop the test, verify that the cursor is positioned at the Stop
command.
4. Press Enter.
Status is changed to Inactive.
The DSL Line Loopback cannot be started when any other loopback is in progress
and will only start if the DSL link is up.
DSL
Port
G.703
Port
E1
LIU
Framer
Framer
Transceiver
AIS
02-17127
