Scaling conference bridge applications, multi site

Scaling conference bridge applications

I wonder if anyone has configured a group of asterisk servers to work as a cluster of conference bridges.

By this I mean calls can be answered by any conference bridge and linked to a conference hosted across multiple bridges.

Each bridge would conference (when active) rooms together.

An example would be bridges located in London, New York and Paris.
20 participants join a conference in London, 10 from New York and 5 from Paris.
Each local bridge will conference local callers together but join the same room in London, New York and Paris with a single call thus cutting down on international traffic and increasing capacity and resilience.

I can see how I might do this in the dial plan for a single room not containing pins but not for example a dynamic conference with pins.

In addition if you are hosting multiple conferences at the same time you do not want to join remote rooms if there are no participants dialled in. For this we will need to pass some presence information which will allow for dynamic conference scaling.

Am I making any sense? Is there a simple solution to this concept?


What about when your user enters a local meetme, to make the asterisk launch a call file
that would join both conferences. You could also set a flag somewhere to prevent it from being
executed twice.

call file:

Channel: local/s@meetme-leg-1
MaxRetries: 0
RetryTime: 30
WaitTime: 5
Context: meetme-leg-2
Extension: s
Priority: 1


exten => s,1,MeetMe(…localmeetme options…)

exten => s,1,Dial(SIP/meetme2server/…)

Thanks for the reply. I will put some time in to this idea and see if meets requirments, looks good though.

I guess the issue maybe managment. For one or two meetme’s which have lots of callers this works. If the oposite was true, lots of small meetme’s few participants, managment may become more dificult. Perhaps managment can also be automated with a macro and some varibles.

If anyone else has any examples of working multi server conference bridge configs I would be greatfull to discuss what you have done and what issues arrise.

Many thanks

I have had limited sucsess with the concept of initiating a bridged call via call files.

Are there any other solutions to this problem the community has tested?

I also wonder if there are any features of IAX or DUNDI which would pass presence information about the satus of a confbridge call which wouold allow for calls to be automaticaly joined?

Any thoughts on this matter are greatfully recived.

its done with clever routing and the astdb

joining the rooms can be done with a call file or just a dialplan so that when an admin is logged in calls are fired to the other sites.

Good news, so at least I am on the right path.

Where I have got to so far is to have a script run if the caller is the first to call a particular conference. This also increments a record in astdb so that if a second caller calls in it does not trigger the script which attempts to join the conference bridges together.

The script generates a call file and dials a separate section of the remote servers dial plan which dumps the caller into the remote bridge.

I had a thought that the connecting of the bridges may occur in both directions so perhaps they should join each other muted which should give you two audio paths and a TX and RX in effect. Hmm not sure about this idea.

What did you mean by cleaver routing? and do you have an example of how you have implemented this concept?

May thanks for the pointers.

May I ask what you mean by clever routing?