Troubleshooting
152-319-100-02, Revision 02
40
April 21, 2000
H2TU-C-319 List 1 and List 1C
L
OOPBACK
O
PERATION
HiGain Solitaire has a family of loopback options for analyzing circuit functionality. The loopback signal is
transmitted and returned to the sending device for comparison. This allows you to verify the integrity of the
HDSL2 channels to the H2TU-C, the H2TU-C DSX-1 interface, and the DS1 channels to the customer. Loopback
options include:
•
Generic Loopback (GNLB) options, including the SmartJack (SMJK) option (see
)
•
Special Loopback (SPLB) options (see
“Special Loopback Commands” on page 42
and the following
command tables:
–
Addressable Repeater Loopback commands: A1LB, A2LB, A5LB (see
–
Addressable Repeater Loopback commands: A3LB, A4LB (
)
Loopback commands can be initiated by:
•
Selecting the loopback type using the MODE and SEL buttons on the H2TU-C front panel (or the Manual
Loopback button on the H2TU-R)
•
Selecting the loopback type from the Monitor menu when connected to the craft port of the H2TU-C or
H2TU-R
•
Entering the loopback code into the test equipment connected to the H2TU-C or H2TU-R
Generic Loopback Commands
The HiGain Solitaire Generic Loopback (GNLB) commands allow you to use inband codes to loop up either
NLOC (4-in-7) or NREM (3-in-7) towards the network. In addition, 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 HiGain Solitaire system
responds. HiGain Solitaire also supports NRGx regenerator loopbacks to the network and CRGx regenerator
loopbacks towards the customer. TLOS is a logic loopback caused by loss of the DS1 input from the CI.
summarizes the available loopbacks in the system, and
summarizes the HiGain
Solitaire generic loopback commands. See
“GNLB Test Procedures” on page 44
for the test procedures that apply
when using the GNLB mode.
Figure 25.
Loopback Summary
HiGain Solitaire only supports one active loopback, however, SmartJack loopback can be
present along with one other network loopback.
