Paradyne ACCULINK 336x E1 - Manual (Page 75)

Maintenance
4-17 3360-A2-GB20-20 December 1996
Starting a Line Loopback
The Line Loopback command (LLB) loops the
received signal on the network interface back to the
network without change. All ones are transmitted on the
G.703 DTE port for the DS0 channels allocated to the
network interface. All ones are also transmitted to each
synchronous data port allocated to the network interface.
NTU
DTE
(G.703)
LLB HDSL
AIS
LINE LOOPBACK (LLB)
495-14758
To perform a Line 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, select LLB.
F1
Loopback:
Abort
LLB PLB
F2 F3
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 4-9 for valid
loopback test combinations).
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 G.703
DTE port as possible (after it has passed through the
framing circuitry of the E1 NTU). Therefore, framing
CRCs and BPVs are corrected. All ones are transmitted on
the G.703 DTE port for the DS0 channels allocated to the
network interface. All ones are also transmitted to each
synchronous data port allocated to the network interface.
NTU
DTE
(G.703)
PLB HDSL
AIS
PAYLOAD LOOPBACK (PLB)
495-14759
To perform a Payload 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, select PLB.
F1
Loopback:
Abort
LLB PLB
F2 F3
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 4-9 for
valid loopback test combinations).