Advertisement
L
OOPBACK
Initiate loopback testing from the maintenance menus. The inband codes shown below can
be sent by a test set.
Network
Downstream
Loopback
Inband Code
NLOC
1111000
NREM
1110000
CREM
1111110
CLOC
1111100
SMJK
11000
Loopdown
11100
LED and Status
DSL
Flashing red once every second HDSL2 loop is attempting synchronization.
ALM
DSX/DS1
ESF/SF
Flashing yellow once every second ESF frame formatting and frame error/CRC are present at the H2TU-C.
Flashing green once every second SF frame formatting and frame error are present at the H2TU-C.
B8ZS/AMI
Flashing yellow once every second B8ZS and excess zeros string are present at the H2TU-C.
Flashing green once every second AMI and BPV are present at the H2TU-C.
LBK
To comply with the intrabuilding wiring requirements of GR-1089
CORE, Section 4.5.9, the shields of the ABAM-type cables that
connect the line unit DSX-1 output ports to the cross-connect
panel must be grounded at both ends.
T
ESTING
H2TU-C
DSX-1
NLOC
CREM
* When enabled, TLOS is an automatic loopback
that occurs with an LOS at the remote DS1 input.
Table 1. GNLB Loopback Commands
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 customer is looped back to the customer at the H2TU-C.
DS1 signal from customer is looped back to the customer at the H2TU-R.
DSX-1 signal is looped back to the network at the H2TU-R SmartJack module.
Deactivates any of the above loopbacks.
Table 2. LED Status and Functions
Function
OFF No power is applied to the H2TU-C.
Solid green Normal operation: HDSL2 span is synchronized without error.
Solid red HBER, MARG, or PWRF alarm is present at the H2TU-C.
OFF Normal operation: the DSX-1 signal is present at both the H2TU-R and
H2TU-C.
Solid yellow RLOS is present at the H2TU-R.
Solid red LLOS is present at the H2TU-C.
Solid green Normal operation: the DSX-1 signal is error free.
Solid red LLOS, BPV, frame error, or CRC is present at the H2TU-C.
OFF Unframed DSX-1 is present at the H2TU-C, unit set as unframed, or no
DSX-1 is detected at the H2TU-C.
Solid yellow ESF frame formatting is present at the H2TU-C.
Solid green SF frame formatting is present at the H2TU-C.
OFF No DSX-1 signal is present at the H2TU-C.
Solid yellow B8ZS is present at the H2TU-C.
Solid green AMI is present at the H2TU-C.
OFF H2TU-C is not in loopback.
Solid yellow H2TU-C is in either NLOC or CREM (RLB).
H2TU-R
DS1
NREM
CLOC
SMJK
TLOS*
Upstream
Customer
Premises
H0025-A
Advertisement
