3 way conference


I am newbie and have just completed installing an Asterisk server (I don’t remember the version number) and I access it using FreePBX ver.

We are trying out 3 zyxel IP phones v300. The phones have a Conf key. When I press it after receiving a call to conference in another extension, it doesn’t do anything.

I have 2 PSTN lines. One line I set for a Zap trunk (I have an 8 port Digium card) and another line combined with the former line as incoming.

All my extensions are SIP extensions.

Is the Conference key a phone operation or do I have to configure anything on the Asterisk server? When I press Conf key after receiving a call, does it dial a Feature as in Misc destination?

I read in one of the forums that if you only have one PSTN line, one cannot do 3 way conference. However, I am thinking, I am only conferencing another extension which is not supposed to be using a PSTN line. Is that correct?

Then I also am confused about Channels. I set the Channel to a maximum of 4. Does that mean, I can have 4 simultaneous calls on one PSTN line.

Any help or clarification, I will be very grateful.


It would help if you posted your phones specs, but to setup a conference you create a conference extension to which you would dail and transfer to like a normal extension.

So in the freepbx setup you would create a conference extension then transfer people there.

Check your phones administration manual about how to program the button, you might be able to program it to auto dial a default conference extension.

My understanding which at times is wrong is that if you have the line open you should be able to place those people inside the conference room.

If you have an Aastra phone, by default when you have an active line, there is a conference key that comes up on the display. This is done independently by the phone. Its pretty cool, you can be on the phone, hit Conf dial an extension OR dial an outside number. then when the second call picks up hit conf again and it’ll join the calls. BTW i have aastra 57i’s and 6757i’s.

I believe you CAN make a key to dial for the Meetme conferencing, which all it would do is dial your conference extension.

So, my issue. I did go into the conference config page, and setup conference ext 850. Now with or without a pin set, i get the “that is not a valid conference number”.

What am i doin wrong, anybody???