[Asterisk-Dev] Basic Conferencing from IAX2, other VoIP Channels

[Nicolas Gudino]

Hi Steven,

On Wed, 2004-06-02 at 16:08, Steven Sokol wrote:
> Asterisk's MeetMe is powerful and flexible, but sometimes you just want to
> do an old-fashioned basic conference from the client, without having to
> transfer everybody into a conference room.  This is pretty common
> functionality on most office phone systems.
> 
> Scenario:
> 
> 1.  You (party A) are on an active call with party B.
> 2.  You decide to add in another party (C).
> 3.  You key the CONF button on your business set.
> 	- Party B gets MOH or silence.
> 	- Party B's appearance on your phone goes to the HELD state.
> 	- You get new dial-tone on a new appearance
> 4.  You dial the number for party C.
> 5.  Party C answers and you communicate briefly.
> 6.  You press the CONF key again to establish the conference
> 	- The bridging takes place in the PBX/KSU
> 	- Party B is pulled out of MOH-land and added to the new call
> 	- Party B's appearance returns to the ACTIVE state
> 
> Now you are conferenced.  Both call appearances show active.  You can even
> follow the same set of steps to conference in another user if you have
> additional appearances on your set.
> 
> In Asterisk using most VoIP phones (soft or hard) this scenario does not
> play out.  You wind up transferring party A into the MeetMe, calling party B
> and transferring them into the MeetMe, then dialing into the MeetMe
> yourself.

I use SIPURAS and they handle 3 way conferences themselves, using the
exact same procedure you describe. (they are limited to 3 parties
conferences). 

> 
> This is further complicated by the fact that any given static MeetMe may or
> may not already be occupied by others doing the same thing.  Dynamic MeetMes
> make this a bit more flexible, but there's little documentation to the
> dynamic feature.

You don't need dynamic meetmes, you need to configure the rooms in
meetme.conf and then use meetme's 'E' option (selects and empty pinless
conference). If you have enough rooms configured, you will not run out
of empty meetmes to transfer people to... 

> 
> Is there an elegant way to execute dynamic conferencing in Asterisk?  Can
> this be done without building conferencing logic into the client UA?  If so,
> how?

I have implemented this feature in the Flash Operator Panel using the
manger "dual redirect" and meetme's  'E' option. 

The operator panel first performs the dual redirect, then looks in the
manager events for the meetme room number that was used for one of the
channels, and then originates a call to that room for the third party.

But I agree that Asterisk needs a feature like the '#' trasnfer, that
works with all channel types, at least for performing 3 parties
conferences directly from the UA.

-- 
Nicolas Gudino <nicolas at house.com.ar>
House Internet S.R.L.