Ds1 And Dsx-1 24-Hour Pm Threshold - ADC HiGain H2TU-C-319 List 4E User Manual

Provisioning
HDSL2 BER Threshold (HBER) Option. The HBER option permits the monitoring of loop integrity and
reporting of alarms when excessive errors are detected. The PM primitive used for this purpose is the CRC
checksum performed on the HDSL2 frame for both directions of transmission. It is, therefore, called a block error
rate rather than the bit error rate associated with the DS1 interface. The CRC errors and counts are displayed on
the Monitor screen for both the H2TU-C and H2TU-R. The HBER option allows an alarm to be generated if the
total number of CRCs at either the H2TU-C or H2TU-R exceeds the selected BER threshold during the last
1-minute interval.
•
HBER option = 1E-6. Alarm is generated if CRC > 93
•
HBER option = 1E-7. Alarm is generated if CRC > 9
Once initiated, the HBER count clears when the CRC count drops below the selected threshold. Selecting NONE
inhibits this alarm.
H2TU-C Equalization (EQL) Option. Equalization is the configuration of system transmission characteristics
within specified limits. An adaptive equalizer inserts a frequency-shaped loss that corresponds to an equivalent
addition of an appropriate cable length. By simulating the additional cable loss necessary for correct operation,
the equalizer compensates for a range of variation in transmission path characteristics.
Alarm Pattern (ALMP) Option. To improve HiGain HDSL2 compatibility with the switch-to-protect features
used in Digital Loop Carrier (DLC) feeder applications, the H2TU-C has an Alarm Pattern (ALMP) option that
allows you to select either an AIS or LOS DS1 output payload for the following alarms:
• LOSW on any loop
• LOS DS1
Bipolar Violation Transparency (BPVT) Option. The H2TU-C improves compatibility with Digital Loop
Carrier (DLC) feeder applications because of its ability to transmit DS1 BPV occurrences between its DS1
interfaces. This feature is required to support protection switching in DLC applications. Each DLC terminal must
be able to monitor the integrity of its Receive DS1 payload and then switch to the protect line when the integrity
of the path drops below specific user selected limits. An essential requirement of this feature is the need for each
DLC terminal to detect BPVs in its DS1 input. Standard HDSL systems correct DS1 BPVs at the input and
therefore prevent them from being detected by the DLC terminals to which they are connected. The H2TU-C and
its associated remote units remove this limitation and become BPV transparent by detecting and counting input
BPVs at each end and then by replicating them at the DS1 output port of the distant end.
The BPV count is converted into BPVs at the distant end during the following second at a rate of 1 BPV every
128 DS1 bits up to a maximum of 12000 (BER = 7.7 x 10
exceeds the maximum 10
DS1 BER (DBER) Option. The DS1 BER alarm occurs when any of the DS1 or DSX-1 performance
monitoring parameters listed in
through 11:59:59 PM. These thresholds correspond to a 10
or when Master Clear is selected. See
22
-3 BER required by most DLC systems.
Table 7 exceed the counts shown for the 24-hour period between 12:00:00 AM
"Clearing the History, Alarm, and Event Log Screens" on page
Table 7. DS1 and DSX-1 24-hour PM Threshold
Parameter
CV-L (BPV)
ES-L, ES-P, PRM, PDVS-L
SES-L, SES-P
UAS-P, UAS-L
January 9, 2002
-3
). This maximum rate is more than adequate since it
-6
BER. All PM counters clear to zero at 12:00:00 AM
Threshold Count
133,400
648
100
10
LTPH-UM-1049-02, Issue 2
33.
H2TU-C-319 List 4E