Figure 7: Method 1 - Configure Fxo Port On The Ht503: Fxo Termination - Grandstream Networks UCM6100 Series Configuration

Figure 7: Method 1 - Configure FXO Port on the HT503: FXO Termination


First we should confirm which method the PSTN line is using. If the PSTN line is using current
disconnect (typical case in North America), then we should turn on "Enable Current Disconnect" and
disable "Enable PSTN Disconnect Tone Detection".
The default "Current Disconnect Threshold" is 100ms, but if you start experiencing dropped calls then
you should raise this value by 100ms intervals.

If the PSTN disconnects using the tones method, then turn on "Enable PSTN Disconnect Tone
Detection" and turn off the "Enable Current Disconnect" option.
For PSTN tone detection, the tone disconnect method is widely used everywhere else in the world.
The North American busy tone value is "f1=480@-32,f2=620@-32,c=500/500" but these tones vary
from country to country. You may look up for the settings for your country at
download the information from http://www.itu.int/ITU-T/inr/forms/files/tones-0203.pdf.

Set "Number of Rings" option to 1. If you happen to experience caller ID issue, you may set it to 2.
Firmware Version 1.0.1.25 Configuring UCM6100 Series with HT503
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