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

ACCULINK 317x 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,
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 Table 4-8 for valid
loopback test combinations).
4-16
Ptrns
F2 F3
LLB PLB
F2 F3
March 1996

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,
1. Press F2 to select Test from the top-level menu
screen.
2. From the Test screen, press F2 to select Lpbk.
Test:
Rlpbk Lpbk
F1
3. From the Loopback screen, press F3 to select
PLB.
Loopback:
Abort
F1
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 Table 4-8 for
valid loopback test combinations).
Ptrns
F2 F3
LLB PLB
F2 F3
3170-A2-GB20-10