atcomsystems.ca/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Disconnect detection using VOIP lines as Definity CO lines?

My G3 switch has a trunk group with two members, both of which are VOIP lines from different providers. I set up the trunk group as two-way, loop start.

The switch doesn't seem to want to detect a disconnect from either of the lines (i.e. the switch is not "hanging up" and returning the CO line to "idle"). If I make an inbound call to the switch and the call is not picked up, the extension on the switch will ring in perpetuity (I guess?), long after I've hung up as the calling party. I've tried playing with the Answer/Disconnect Supervision settings for the trunk group, which did not help. Are there other settings I should adjust to try and correct this?

Without a positive disconnect signal the system has no way of knowing when the calling party hangs up.

I would check with the service provider to see what they can do to resolve the issue.

Definity's do not seem to like VOIP lines, disco is one problem. Putting a IP front end on it might help.

Have you determined that you are even getting a disconnect signal from the VoIP line?

Ah, I think that is the right question...

How do I determine if I'm getting a disconnect signal from the VOIP line?

Put a tone generator on the pair for the line being tested, but do not turn it on. You will get a light on the LED indicator of the tone generator.

Place a call into the trunk being tested and have someone answer it. Have them place the call on hold.

Hang up from your test call and watch the LED of the tone generator. If it goes our for about half a second a few seconds after you hang up, then the disconnect signal is being sent. If the LED stays lit continuously, then you are not receiving the required disconnect signal.