Trainer/Trainee team Ring Group Auto Conference setup - Need help pointing me into the right direction


We just upgraded to the current distro with a few commercial modules. all the basic and easy stuff are working fine. But as part of the rollout I have a tough customer request and after searching everywhere I hope the community can help me out…

Lets say a call comes in via a SIP Trunk on a particular DID, we want it to ring John and Ben (x801 and x802) simultaneously, so use Ring Group you say? wrong, read on…

John is training Ben so when either of them picks up the phone, we want the extension that’s still on-hook to be able to join the call if required. so use Call Barge you say? wrong, read on…

With call barge the extension that picked up the outside caller will have control of the call. Lets say John x801 picked up the call, John tells Ben x802 to join, so Ben does so via barging, 3-way conversation happens, everybody is happy for now. But now John would like to tell Ben to continue and finalize things with the caller and ideally John himself can now hang up or take another call. But he can’t because if he does the call will terminate.

Similarly if another caller calls in while the 3-way call is in progress, John can’t leave the call and pick up the new call. if he hangs up the call in progress will terminate. if he go on hold the current call will get hold music while the caller and Ben is still having a conversation…

On top of all these. We would like to be able to set a BLF for other similar teams/cells to be able to pick up John/Ben’s call when they are unable to and vice versa.

Yeah they don’t want much…

So the ideal behavior is a little like 2 dumb POTS phone wired in parallel. either can pick up, either can hang up and only the last extension that hangs up actually terminates the call… That’s how they explained it to me (!) of course they conveniently left out little details like they might actually like to be on calls to different parties, multiple incoming lines and BLF etc that a dumb POTS phone don’t do…

So what should I do? I was thinking towards virtual extensions and conference rooms for incoming calls (but how to handle the second outside caller while a call is ongoing?, last thing we want is to put 2 outside callers into the same call))… If someone can help pointing me to the right direction I’d be much obliged…

Once this is solved we can look at the BLF as it kinda depends on what we come up with at the end for the main requirement.

If you have read this far I thank you for your interest. All offer of help will be appreciated.


Well I guess the one way to do this would be to ring them both via a Local channel and when one of them answer, build a dynamic conference bridge to put the caller/callee in. If either the Trainer or the Trainee need to join the call, they can dial into the conference bridge. The trick will be getting that conference bridge to the person that wants to “barge” in. So you’ll need a feature code/exten that can be dialed and look for information like what the conference bridge is and join the call there. Maybe a static conf bridge…

This is not something that can be done directly in FreePBX without a commercial module. Even then I’m not sure if any of them offer this functionality. You very well may be looking at something third party or even might have to do this in-house. I’m pretty sure what you are looking to do here is possible but it’s going to require some AMI(or ARI) interaction and a bit of custom coding/dialplan for it to happen.

1 Like

Thanks Tom, yeah I was fearing messing with AMI/.ARI and dialplan were the answer…

Anywho, I will wait a few days in case someone comes up with something we’ve overlooked, may be something can be clobbered together with the commercial queue / conference modules…

If I don’t get anything I’m going to give them the good news. Who knows, if they want it bad enough I might get a budget to contract someone as my coding days are but a distant memory. :slight_smile:

any takers?

What you are asking sounds a lot like “Shared Line Appearance” or SLA. That is someting really difficult to achieve on Asterisk, if not impossible. Some brands implement it by means of propietary code, like Linksys with its old SPA9000 or Grandstream with their UCX line. Since UCX is using Asterisk, I guess there must be some way of doing it, but probably some sort of code is also embedded on the phones, because UCX can only do SLA with Grandstream phones, the same way SPA9000 can only do SLA with SPA9xx phones.

Shared Line Appearance, regardless if the phone supports it or not, is not supported in Asterisk.

Thanks for the terminology, knowing what I’m looking for is half the battle!

Andrew Nagy of Sangoma had the following from another thread FPBX12/Asterisk13 - SCA’s, baby

another lead:
Achieving Shared CALL Appearance (SCA, not SLA)

I shall go through those and see if there’s anything there. In the meantime, everyone don’t be shy to chime in! :slight_smile:

1 Like

FYI, Shared Line Appearance is not the same as Shared Call Appearance

1 Like

Both are doable using asterisk’s ari.

1 Like

Indeed, but as my users are also a bit vague on what they really want reading up both helps me get to what I think they want. or at least being able to articulate it to them.

So there are no functions or modules in FreePBX that can achieve this? Existing or planned?

Looks like I either get my coding pants back on or drop some coin and find someone much better qualified than me… :smile:

The code to do this exists in the asterisk github repo. It’s about 3 years old and was coded by interns. It’s not geared for freepbx but I have made it work in freepbx. It needs a lot of TLC

As for freepbx. It’s a pretty commonly requested feature but I can’t comment on future commitments.

I’d say fast-track it. Users requesting this feature are likely to be Bosses and their assistants, and they’re the ones approving the purchase order for commercial modules! :rofl::rofl::sunglasses:

@affa So based on what you described originally and wanting this to perform like two dumb POTS lines, this might be doable with a little work and not as big as you think. So two POTS lines, let’s say with no Call Waiting which means 1 call per line.

  1. You set up two conference bridges. Line 1 and Line 2.

  2. You send calls to the DID(s) to a custom Ring Group that calls 801 and 802 via Local channels and when one of those answers you bridge both the call and whoever answers into one of your conference bridges.

  3. If a new call comes in while 801 is on a call/in a bridge then it is up to you if you want to ring 802 and then bridge them into the second conference bridges.

  4. Figure out what to do when both “lines” are busy or when both 801 and 802 don’t answer and the call is not picked up.

  5. If the phone can support BLF based Call Pickup then when another user picks up the call to 801 or 802 they are answering the Local channel and that should also bridge them into one of the available conference bridges. You could also make it so if it is answered by someone other than 801 or 802 then they don’t go into a conference bridge and the call is just bridged normally.

  6. Use custom Hints (or available ones) to track the conference bridges states so others can BLF the conference bridge to see when it is in use and even dial into it and join the call.

This way the caller is in the bridge and 801/802 or anyone can join/leave without the caller being disconnected and if the caller is the only one in the bridge you can play MoH for them. Like I said it’s going to require some custom diaplan/setup but while it’s going to be a job, it’s not an overly big job.

Thanks for your time in laying it all out. I shall have a crack at it. It might just get us by.

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.