Paradyne ACCULINK 336x E1 - Manual (Page 74)

ACCULINK 336x E1 NTU
4-16 December 1996 3360-A2-GB20-20
Local Loopback Tests
The Local Loopback tests enable you to conduct circuit
testing and fault isolation for the digital line. The
supported local loopback tests are:
•
Line Loopback (LLB)
•
Payload Loopback (PLB)
•
DTE Loopback (DLB)
•
Repeater Loopback (RLB)
•
Data Channel Loopback (DCLB)
•
Data Terminal Loopback (DTLB)
NOTE
DLB does not appear when the
G.703 DTE interface is disabled.
The Line Loopback command can be activated and
deactivated in response to commands received over the
network interface. The Network Interface configuration
option NET LLB controls whether the E1 NTU responds
to the commands transmitted on the network interface to
initiate LLBs (see Appendix C,
Configuration Options ).
The data port configuration option NET DCLB
controls whether the E1 NTU responds to inband V.54
commands to initiate DCLB for that port (see
Appendix C,
Configuration Options ).
Local loopback tests can be aborted (Abort Command)
at any time.
No more than two local loopbacks can be active at any
one time. An additional restriction prohibits certain
loopbacks from running at the same time. Valid loopback
combinations listed in
Table 4-9 are identified by YES.
Table 4-9
Valid Loopback Combinations
LLB PLB DLB RLB DCLB DTLB
LLB N/A NO YES YES NO YES
PLB NO N/A YES NO NO YES
DLB YES YES N/A NO YES YES
RLB YES NO NO N/A NO YES
DCLB NO NO YES NO YES
(on separate
ports)
YES
(on separate
ports)
DTLB YES YES YES YES YES
(on separate
ports)
YES
(on separate
ports)