7
Section 61245001L7-5, Issue 1
61245.001L7-5A
HTU-R, and HRE. This scenario was chosen for
inclusiveness of functionality. However, other
configurations are possible and their displays will vary
slightly from those shown in this section.
A terminal session is initiated by entering multiple space
bar characters, which are used by the HTU-C to determine
the speed of the terminal. Once the speed has been
determined, an Introductory Menu is presented, as
illustrated in Figure 7.
From the Introductory Menu, the Main Menu may be
selected. The Main Menu provides access to detailed
performance and configuration information, as illustrated
in Figure 8, HDSL Main Menu Screen.
From the Main Menu, the following screens can be
accessed.
1.
Current System Status
2.
Performance History
3.
ADTRAN Information
4.
Loopback Options
5.
Self Test
6.
Provisioning
7.
Troubleshooting
The Current System Status screen illustrated in Figure 9
provides quick access to status information for both the
HTU-C and HTU-R. By pressing H, the Current System
Status screen for the HRE will be displayed. See Figure
9A for the HRE Current System Status screen.
The Elapsed Time display indicates the period of time
since the unit began collecting performance information.
At each 15-minute interval, the performance information
is transferred to the 15-minute performance data register
accessed from the Performance History screen. At each
24-hour interval, the performance data is transferred into
the 24-hour performance data register also accessed
using the Performance History screen. The Performance
History screen is shown in Figure 10. By pressing H, the
Performance History screen for the HRE will be displayed.
See Figure 10A for the HRE Performance History screen.
By pressing the letter Z at the Current System Status
screen, the current performance registers will be reset to
zero on the Current System Status screen and
Performance History screen.
Figures 9 and 9A consolidate current information for the
HDSL, DSX-1, and DS1 interfaces. A key to the information
provided is found in the center of the screen. Arrows
indicate the key applies to both the HTU-C and HTU-R.
LOSS ................. Pulse Attenuation Measurement *
* LOSS is typically several dB less than the insertion loss
measured at 200 kHz. The LOSS measurement is a better
indication of the loop’s attenuation of the 2B1Q signal than the
insertion loss measured at a single frequency. Adtran HDSL
can operate on cables with an excess of 30 dB LOSS.
SYNC ................. HDSL Loop 1 and Loop 2 Sync Status
ES 15M/24H ...... Errored Seconds*
SES 15M/24H .... Severely Errored Seconds*
UAS 15M/24H .... Unavailable Seconds*
* The first number is for the current 15-minute period and
the second is the current 24-hour period (Loop 1 and
Loop 2 numbers are displayed).
An indication of Pair Reversal (if present) is given at the
bottom of the first key column. Status and configuration
information for the DS1 and DSX-1 signals is located in
the center of the screen near the bottom.
FRAME ....... T1 Framing Format selected
CODE ......... T1 Line Code selected
LBO ............. Line Build-Out selected (for DSX-1);
Customer Signal of 0 or –15 dB (for DS1)
NIU .............. Network Interface Unit enabled?
BPV ............. Bipolar Violations detected (DSX-1 and DS1)
ES ............... Errored Seconds (DSX-1 and DS1)
SES ............. Severely Errored Seconds (DSX-1 and DS1)
UAS ............ Unavailable Seconds (DSX-1 and DS1)
Alarms ......... Lists current alarm condition status
A measure of signal quality for each HDSL loop is
displayed in graphic form on the bottom of the screen.
The measure is from 0 (poor signal quality) to 9 (excellent
signal quality). Guidelines for interpreting the indicators
are given below.
0 ......... Noise margin is
≤
0 dB (
≈
10
-7
BER)
1-8 ...... Margin measurement above 10
-7
BER in dB
9 ......... Margin is
≥
9 dB (excellent quality) above 10
-7
BER
Predicting performance based upon signal quality varies
with each loop. Generally, a noise margin of 0 or higher
will support a bit error rate of better than 10
-7
. ADTRAN
has defined the following as guidelines that correspond
to the operation of the HTU-C faceplate LEDs labeled
LP1 and LP2.
Margin < 0 ( Red) .................... Poor Loop Quality
0
≤
Margin
≤
2 (Yellow) ........... Marginal Loop Quality
Margin > 2 (Green) .................. Good Loop Quality
Figures 11 and 12 depict the HDSL Loopback and Self
Test Option screens. Loopbacks and Self-Test may be
evoked or terminated using these screens. A status of
current loopback conditions is also provided.
Figure 13 displays current provisioning settings and allows
for changing the system configuration. Provisioning changes
are only allowed at the CO end of the circuit. Provisioning
changes made through this screen override the manual
switch settings. The unit retains the last provisioning
changes to determine its operating mode.
