Monitoring and Testing
4-133163-A2-GB20-10 March 1999
Starting a Repeater Loopback
The Repeater Loopback command (RLB) loops the
signal being sent to the network back to the data port. The
signal is looped back as close to the network interface as
possible (after it has passed through the framing circuitry
of the DSU/CSU). Framing CRCs and BPVs are
corrected.
98-15948
CSUDSU
NETWORK
INTERFACE
RLB
PORT 1
ALL 1s
"Procedure
To perform a Repeater loopback:
1. From the top-level menu screen, select Test.
2. From the Test screen, select Lpbk.
F1
Test:
Rlpbk Lpbk Ptrns
F2 F3
3. From the Loopback screen, press the key until
the RLB selection appears on the screen.
4. Select RLB.
F1
Loopback:
LLB PLB RLB
F2 F3
Test Started appears on Line 2. If a Repeater
loopback is already in progress, the Already
Active message appears. If an invalid combination
of loopbacks is in progress, the error message
Invld Test Combo appears (see Table 4-5 for
valid loopback test combinations).
Starting a Data Channel Loopback
The Data Channel Loopback command (DCLB) loops
the data received from the network interface, for all DS0
channels allocated to the data port, back to the network.
The loopback occurs after the data passes through the port
circuitry but before it is sent out the data port.
98-16103

CSUDSU

NETWORK
INTERFACE
DCLB
"Procedure
To perform a Data Channel loopback:
1. From the top-level menu screen, select Test.
2. From the Test screen, select Lpbk.
F1
Test:
Rlpbk Lpbk Ptrns
F2 F3
3. From the Loopback screen, press the key until
the DCLB selection appears on the screen.
4. Select DCLB.
F1
Loopback:
PLB RLB DCLB
F2 F3