Starting A Line Loopback; Starting A Payload Loopback - Paradyne 3172 Operator's Manual

ACCULINK 3172 and 3174 E1 DSU/CSU

Starting a Line Loopback

The Line Loopback command (LLB) loops the
received signal on the network interface back to the
network without change.
To perform a Line loopback:
"
Procedure
1. Press F2 to select Test from the top-level display
screen.
2. From the Test screen, press F2 to select Lpbk.
Test:
Rlpbk Lpbk
F1
3. From the Loopback screen, press F2 to select
LLB.
Loopback:
Abort
F1
Test Started appears on Line 2. If a line 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
loopback test combinations).
4-16
Ptrns
F3
F2
LLB PLB
F2 F3
Table 4-8 for valid

Starting a Payload Loopback

The Payload Loopback command (PLB) loops the
received signal on the network interface back to the
network. The signal is looped back as close to the DTE
Drop/Insert port as possible (after it has passed through
the framing circuitry of the E1 DSU/CSU). Therefore,
framing CRCs and BPVs are corrected.
To perform a Payload loopback:
"
Procedure
1. Press F2 to select Test from the top-level menu
screen.
2. From the Test screen, press F2 to select Lpbk.
3. From the Loopback screen, press F3 to select
PLB.
Test Started appears on Line 2. If a Payload
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
valid loopback test combinations).
March 1999
Test:
Rlpbk Lpbk Ptrns
F1 F2 F3
Loopback:
Abort LLB PLB
F1 F2 F3
Table 4-8
3170-A2-GB20-30
for