ADC HDSL4 Manuale Utente
Testing
LTPH-UM-1031-03, Issue 3
52
September 12, 2003
H4TU-C-319 List 1
To perform the GNLB loopback test procedure:
1
Have the CO tester send the NREM (3-in-7) inband loopup code for 5 seconds. You should observe the
NREM message on the front-panel display. (The Status LED on the front panel should be green, and the
loopback mode should also be identified on the Monitor screen.)
NREM message on the front-panel display. (The Status LED on the front panel should be green, and the
loopback mode should also be identified on the Monitor screen.)
2
Have the CO tester transmit a DS1 test signal towards the H4TU-C and verify that the returned (looped) signal
to the test set is error-free.
to the test set is error-free.
3
If step 2 fails, have the CO tester transmit the (3-in-5) inband loopdown code.
4
Have the CO tester send the NLOC (4-in-7) inband loopup for 5 seconds. You should observe the NLOC
message on the front-panel display. (The Status LED on the front panel should be yellow, and the loopback
mode should also be identified on the Monitor screen.)
message on the front-panel display. (The Status LED on the front panel should be yellow, and the loopback
mode should also be identified on the Monitor screen.)
5
Repeat Step 2. If the test passes, the problem is in the downstream direction. If it fails, the problem is in the
upstream direction.
upstream direction.
A3LB Test Procedure
The H4TU-C-319 can be looped back by sending the Addressable Office Repeater (AOR) LPBK activation code
1111-1111-0001-1110 (FF1E) for at least 5 seconds. This causes the H4TU-C to enter the NLOC state. The
Loopback Time-Out setting (see
1111-1111-0001-1110 (FF1E) for at least 5 seconds. This causes the H4TU-C to enter the NLOC state. The
Loopback Time-Out setting (see
) determines the
duration of this loopback unless it is overridden by the reception of a second identical 16-bit loopup command
before the timer expires. When this time-out override state exists, the only way to loop the H4TU-C down is to
issue one of the three loopdown commands listed in
before the timer expires. When this time-out override state exists, the only way to loop the H4TU-C down is to
issue one of the three loopdown commands listed in
. The automatic time-out mode is restored during
subsequent loopback sessions.
summarizes the codes required to execute an A3LB Addressable Repeater Loopback command. All code
sequences must be present for at least 5 seconds.
Table 17.
A3LB Addressable Repeater Loopback Commands
Name
Binary Code
(a)
(Hexadecimal Equivalent)
(a) The leftmost bit arrives first in all sequences. The detection algorithm functions reliably with a random 10
-3
Bit Error Ratio
(BER) on the facility. The entire arming and loopback sequence can also be initiated at the remote H4TU-R location.
Description
NLOC
1111-1111-0001-1110 (FF1E)
H4TU-C loopup from NI.
CREM
0011-1111-0001-1110 (3F1E)
H4TU-C loopup from CI.
NREM
1111-1111-0000-0010 (FF02)
H4TU-R loopup from NI.
NDU1
1111-1111-0000-0100 (FF04)
Signal is looped back to the network at H4D1.
CDU1
0011-1111-0000-0100 (3F04)
DS1 signal from customer is looped back to the customer at H4D1.
NDU2
1111-1111-0000-0110 (FF06)
Signal is looped back to the network at H4D2.
CDU2
0011-1111-0000-0110 (3F06)
DS1 signal from customer is looped back tot he customer at H4D2.
D1LB
Dual loopback at H4D1.
D2LB
Dual loopback at H4D2.
CLOC
0011-1111-0000-0010 (3F02)
H4TU-R loopup from CI.
SMJK
11000-11000-11000 ...
H4TU-R loopup from NI.
SMJK
100000 100000 100000 ...
H4TU-R loopup from NI.
SMJK
1111-1111-0100-1000 (FF48)
H4TU-R loopup from NI (ESF-DL).
Loopdown
11100-11100-11100 ...
H4TU-C and H4TU-R loopdown from NI OR CI.
Loopdown
100-100-100 ...
H4TU-C and H4TU-R loopdown from NI OR CI.
Loopdown
1111-1111-0010-0100 (FF24)
H4TU-C and H4TU-R loopdown from NI OR CI (ESF-DL).