Altigen ACC 6.7, Administration Manual

Page: 174 / 462

Chapter 12: Trunk Configuration
160 MAXCS ACC 6.7 Administration Manual
Using the Match Impedance Button
Whenever a new analog trunk is connected to an empty port or is replacing an existing
trunk, you will need to use the
Match Impedance button to select the best impedance
profile.
To do this, follow these steps:
1. Click the
Impedance Match button. While the impedance match is in process, you’ll
see a “progress” box.
When the process is complete, the Match Impedance dialog box is displayed, with
information relevant to this trunk:
Figure 84. Match Impedance dialog box
The Impedance parameter setting in the main dialog box is changed to the best
match selection, and the measurement for noise and returned echo is performed
with this impedance setting. The results of this measurement are displayed in the
Diagnosis section of the main dialog box. The Hybrid Echo Return Loss field
shows the measurement before adaptation of the selected Impedance profile, and
the
Echo Return Loss field shows the measurement after adaptation of the selected
Impedance profile.
Note: If the Hybrid Echo Return Loss reading of a trunk is worse than -6 dB, for
example, -5 db, the trunk may be subject to VoIP voice quality problems. Use
this trunk to connect to analog phones only, or configure it to be the least
used trunk. (Acceptable range for Hybrid Echo Return Loss is -6dB to -26dB.)
Noise Level should be less than -67dBm (acceptable range is -67dBm to -
90dBm).
2. Make calls from the trunks to test voice quality.
3. Repeat steps 1 and 2 for all other trunk channels.
If the Hybrid Echo Return Loss and Noise Level are not within the acceptable range, take
the following steps to troubleshoot:
1. Change the trunk to a different port on the Triton board, then diagnose again (this
is to rule out a hardware problem).
2. Check to see if any wire taps to the trunk wire (bridge tap). If so, remove them, then
test again.
3. Request the CO to check the trunk conditions, including Line Loss, and longitudinal
balance.
The Match Result Button
Clicking the Match Result button shows you the result you got the last time you clicked
the Match Impedance button for that trunk. The following dialog box is displayed: