Specifications

Reference Guide
7-31
WAN Card WAN Card User Screens and Settings
LINE LB
The Line Loopback setting controls looping of the full E1 line back to the network. When
on
,
this setting allows end-to-end testing of the line.
LOCAL LB
The Loopback setting controls looping of the full E1 line back to the PCM bus. The options
are
off
and
on
. When
on
, this setting allows testing of local equipment. The system generates
a "Keep Alive–Type 1" pattern on the E1 line.
CH LB
The Channel Loopback setting allows you to place individual DS0 channels in loopback
toward the PCM bus. A channel loopback loops a single DS0 channel and cannot be used to
loop multiple DS0s or a portion of a DS0. Refer to user cards for other loopback options,
which may allow you to loop part of a channel or multiple channels. The options are
on
and
off
.
LB ADDR
The Loopback Address setting, in conjunction with the Channel Loopback setting, specifies
which channel is to be looped back. Only one channel may be looped back at any one time for
each E1 link. The valid selections for E1 lines are
1-31
. Do not loop time slot 16 unless the E1
interface is in no signaling (
nos
) mode.
LB GEN
The Loopback Generate setting generates out-band diagnostic codes that are sent to the remote
equipment. These codes are compatible with DDS networks and allow you to command a
latching loopback at remote DDS equipment. The options are
off
,
llb
(Line Loopback),
plb
(Payload Loopback) and
nlb
(Network Loopback).
Selecting
off
generates a loopback deactivate command corresponding to the last activation
command generated. e.g. if you send a
plb
command and then send an
off
command, the
off
command would be payload deactivate. Note that the actual transmission of the command
happens after you press ‘
s
’ for
Save
. If you have already sent one of the loopback activation
commands, it is recommand that you send an
off
command before sending another loopback
activation command. e.g. this set of selections
plb, off, llb, off
transmits the following
commands: payload activate, payload deactivate, line activate, and line deactivate.