Cisco 7800 Series Phone - Conference feature and DND not working

I’m trying out a new Cisco 7841 phone with FreePBX 12.0.2.

The phone registers without any problems and the phone is functional but I just can’t seem to join 2 parties into a conference call using the conf key on the phone and the DND key not working either.

Conference call behavior:

I call the first party, when the person answers, i press the Conf. key on the phone which gives me a dial tone to call the next party. I call the next party and when that person answers, i should be able to hit the conf. key again to join the parties but instead i get another dial tone.

DND behavior:

If i hit the DND to turn it on, it says “DND is on” but calls still are coming through.

The phone is using the following firmware sip78xx.10-2-1-12.

Perhaps i’m missing something in the XML configuration file the FreePBX generated.

Here is my XML configuration file, just wondering if anyone can see if I’m missing something:

#<?xml version="1.0" ?>

		<timeZone>Eastern Standard/Daylight Time</timeZone>
			<member priority="0">

		<line button="1">




Cisco 7XXX phones bring nothing but sadness and despair… they are cheap for a reason… If you’re not using cisco call manager I would not use the 7xxx series. You would have better luck with a crap Chinese phone.

I figured as much. Already dropped the idea and moved on to the Grandstream GXP2140.