Conf call don't work anymore

Unanswered Question
Apr 4th, 2007


I installed a new branch office, wich a local CCM. Conf call on the IP phones don't work.

I have tested it with the "ad hoc"

mode (when I am online with someone, I push the conf button, then type the nuew number, then I 'm online with the new person, and when I try to make the 3 pers conf by pushing the conf button again, I loose the first person ) The message "unable to make the conf" appears on the IP Phone screen.

Do you have an idea where the problem could come from?

Thanking you in advance

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Rob Huffman Wed, 04/04/2007 - 09:00

Hi Etienne,

What are you using for a Conference Bridge (Hardware or Software). Perhaps this has not been configured yet on the new system.

Here are some good guides that will help you get this setup;

Cisco CallManager System Guide, Release 4.1(3)

Conference Bridges

Adding a Software Conference Device

From this doc;

Adding a Hardware Conference Device

From this doc;

Hope this helps!


nonosensei Thu, 04/05/2007 - 00:13

The conf call in the ad hoc mode ( phone to phone ) does not work, I am not using the conference bridge for the moment.

Rob Huffman Thu, 04/05/2007 - 04:42

Hi Etienne,

The term Conference Bridge is a little misleading in that you would think it unnecessary for simple "Ad-Hoc" conferencing. You do need to set up at least a Software Conference Bridge for this type of funtionality to work. Have a close look at this explanation of **Ad-Hoc conferencing;

Initiating an Ad Hoc **Conference Bridge

Initiate ad hoc conferences in two ways:

Put a call on hold, dial another participant, and conference additional participants.

Join established calls by using the Select and Join softkeys.

Using Conference Softkey for Ad Hoc Conference

The conference controller controls ad hoc conferences. When you initiate an ad hoc conference, Cisco CallManager considers you the conference controller. In an ad hoc conference, only a conference controller can add participants to a conference. If sufficient streams are available on the conference device, the conference controller can add up to the maximum number of participants that is specified for ad hoc conferences to the conference. (Configure the maximum number of participants for an ad hoc conference in Cisco CallManager Administration, Cisco CallManager Service Parameters Configuration by using the Maximum Ad Hoc Conference service parameter setting.) Cisco CallManager supports multiple, concurrent ad hoc conferences on each line appearance of a device.

When the conference controller initiates a conference call, Cisco CallManager places the current call on hold, flashes the conference lamp (if applicable), and provides dial tone to the user. At the dial tone, the conference controller dials the next conference participant and, when the user answers, presses Conference softkey again to complete the conference. Cisco CallManager then connects the conference controller, the first participant, and the new conference participant to a **conference bridge. Each participant Cisco IP Phone display reflects the connection to the conference.

From this good doc;

Try setting up a Software Conference Bridge (it's pretty quick and straight forward) then try your conference call. You should be good to go :)

Hope this helps!


nonosensei Thu, 04/05/2007 - 04:59


Software conference bridge is already set up, and max users (in service paramaters, max users is 4). When I try to join the 3rd participant ( i'm the first), I get him, but when I want to get back the first one in order to make the conf, it does not work.

I make a reset of the ocnference bridge just in case, the same problem happends.



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