Generic Loopback Commands - ADC H2TU-C-202 User Manual

Testing
G L
ENERIC OOPBACK
The HDSL2 Generic Loopback (GNLB) commands allows the use of inband codes to loop up either NLOC
(4-in-7) or NREM (3-in-7) towards the network. Additionally, these inband codes loop up CREM (6-in-7) or
CLOC (5-in-7) towards the customer. Either loopup condition can be terminated (looped down) with the 3-in-5,
SMJK loopdown code. All inband codes must be present for at least 5 seconds before the HDSL2 system responds.
TLOS is a logic loopback caused by loss of the DS1 input from the CI.
Figure 31 on page 51 summarizes the available loopbacks in the system, and
HDSL2 generic loopback commands. See
when using the GNLB mode.
HiGain systems feature the SmartJack option which can emulate a Network Interface Device
(NID) for loopback testing of the HDSL2 circuit. SMJK and NREM loopbacks perform the same
functions, but their initiation differs. SMJK indicates that the loopback was initiated by the 2-in-5
inband command. Conversely, NREM is initiated by the 3-in-7 inband command, or by a
command issued from the maintenance terminal.
Use the inband commands to enable or disable the SMJK loopback options. The HDSL2 system
setting is normally enabled to recognize all inband SmartJack loopback commands.
Table 22. Summary of HDSL2 Loopback Codes and Activation Methods
Loopback Code
NLOC 1111000
4-in-7
NREM 1110000
3-in-7
CLOC 1111100
5-in-7
CREM 1111110
6-in-7
COLB
RULB
SMJK LpUp 11000
(PL) 2-in-5
SMJK LpUp 1111-1111-
0100-1000
(ESF-DL)
SMJK LpDn 11100
(PL) 3-in-5
SMJK LpDn 1111-1111-
0010-0100
(ESF-DL)
52
C
OMMANDS
"GNLB Test Procedures" on page 55
Description
DSX-1 signal is looped back to the network at the H2TU-C.
DSX-1 signal is looped back to the network at the H2TU-R.
DS1 signal from the customer is looped back to the
customer at the H2TU-R.
DS1 signal from the customer is looped back to the
customer at the H2TU-C.
Dual loopback at the H2TU-C. DSX-1 signal is looped back
to the network at the H2TU-C and signal from the customer
is looped back to the customer at theH2TU-C.
Dual loopback at the H2TU-R. DSX-1 signal is looped back
to the network at the H2TU-R and signal from the customer
is looped back to the customer at the H2TU-R.
SmartJack Loopup or NID payload (PL) code. Invokes
H2TU-R loopback toward network.
SmartJack Loopup or NID (ESF-DL) code. Invokes
H2TU-R loopback toward network.
SmartJack Loopdown or NID payload (PL) code. Removes
SMJK, NLOC, NREM, CLOC, and CREM.
SmartJack Loopdown or NID (ESF-DL) code. Removes
SMJK, NLOC, NREM, CLOC, and CREM.
June 28, 2002
LTPH-UM-1161-01
Table 22 on page 52 summarizes the
for the test procedures that apply
Method of Activation
Test Set Craft Port MODE/LBK
X X
X X
X X
X X
X
X
X
X
X
X
H2TU-C-202 List 3F
X
X
X
X
X
X