AltiGen MAXCS 7.0 Update 1 ACM Administration - Manual (Page 168)

Chapter 12: Trunk Configuration
152 MaxCS 7.5 Administration Manual
Performing Impedance Match on Your Own
For each individual analog trunk that is connected to the CO when the system starts up, MAXCS automatically
selects an impedance profile to best match the Triton trunk interface with the CO. In the unlikely event that this
automatic selection does not yield the optimal voice quality, you may want to disable the feature and select the
best impedance by trial and error method.
To disable automatic impedance matching, check the Disable Impedance Match During System Startup
check box.
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 opens, with information relevant to this
trunk:
Figure 95. 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 -6
dB to -26 dB.)
Noise Level should be less than -67 dBm (acceptable range is -67 dBm to -90 dBm).
2. Make calls from the trunks to test voice quality.
3. Repeat steps 1 and 2 for all other trunk channels.
Hybrid Echo Return Loss
The measurement for hybrid echo return loss (displayed after you click
the Diagnose button or the Match Impedance button). Acceptable
range for Hybrid Echo Return Loss is less than -6 dB.
Rx Level at 600 Ohms
The Rx Level measurement at 600 Ohms, obtained by clicking the Test
Rx Level
button. See Test Rx Level button, below.
Test Rx Level button
Tests the receiving level of the trunk channel on a call to your local
CO’s Milli-Watt Test Number after you set the Impedance parameter
to 600 Ohms and the Rx Gain to 0dB. Results are displayed in the Rx
Level at 600 Ohms
field.
Parameter Description