Loopback Operation; Generic Loopback Code (Gnlb); Addressable Repeater Loopback Functions - PairGain HiGain HLU-319 Manual

150-319-142-01
L O
OOPBACK
HiGain has a family of loopback options. The most important of these is the
Smart Jack (SMJK) loopback which enables an HRU response to the standard
(2/3-in-5) SMJK in-band loopback codes in emulation of standard Network
Interface Device (NID) functions. This option can be enabled or disabled
from the front panel using the MODE and SEL buttons or through the System
Settings menu.

Generic Loopback Code (GNLB)

The HiGain generic loopback code is GNLB. The GNLB allows in-band
codes to loop-up either the HLU/NLOC (4-in-7) or HRU/NREM (3-in-7)
toward the network. In addition, it allows in-band codes to loop-up the
HLU/CREM (6-in-7) or HRU/CLOC (5-in-7) toward the customer. Either
loop-up condition is terminated (looped-down) with the 3-in-5 loop-down
code. Both in-band codes must be present for five seconds before the HiGain
system responds.
using the GNLB mode.
The A1LB loopback selection, see
T1E1.4/92 recommendation for HDSL systems, with the following additions:
•
Query loopback
•
IOR (Intelligent Office Repeater) power-down
•
Three loopback time-out choices
•
Initiation from either end
•
Repeating bit error signatures
•
Alternate query loopback
These additions make A1LB identical to A2LB. A1LB is given a separate
identity to allow future T1E1 enhancements without affecting A2LB.

Addressable Repeater Loopback Functions

A HiGain system is capable of five special in-band loopback (SPLB)
command sequences.
HLU-319 List 4B
December 22, 1997
PERATION
Table 4 on page 36
PairGain Engineering - Plant Series
lists the applicable test commands when
Table 5 on page 39, complies with the
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