Local Loopback Tests - Paradyne 3172 Operator's Manual

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
DTE Drop/Insert interface is
disabled.
LLB
LLB N/A
PLB NO
DLB YES
RLB YES
DCLB NO
DTLB YES
3170-A2-GB20-10
deactivated in response to commands received over the
network interface. The Network Interface configuration
option NET LLB controls whether the E1 DSU/CSU
responds to the commands transmitted on the network
interface to initiate LLBs (see Appendix C, Configuration
Options).
controls whether the E1 DSU/CSU responds to inband
V.54 commands to initiate DCLB for that port (see
Appendix C, Configuration Options).
at any time.
one time. An additional restriction prohibits certain
loopbacks from running at the same time. Valid loopback
combinations listed in Table 4-8 are identified by YES.
Table 4-8
Valid Loopback Combinations
PLB DLB
NO YES
N/A YES
YES N/A
NO NO
NO YES
YES YES
March 1996
The Line Loopback command can be activated and
The data port configuration option NET DCLB
Local loopback tests can be aborted (Abort Command)
No more than two local loopbacks can be active at any
RLB DCLB
YES NO
NO NO
NO YES
N/A NO
NO YES
(on separate
ports)
YES YES
(on separate
ports)
Maintenance
DTLB
YES
YES
YES
YES
YES
(on separate
ports)
YES
(on separate
ports)
4-15