Limiting the Number of Simultaneous Calls per Domain in FusionPBX

In the old good days, when the PSTN was rocking, people only had one phone line (or two if they could afford it). This means that regardless of who called who or how many phone extensions your home had, there could only be one call. Some VoIP Service owners find that translating the same behaviour to customers who come from PSTN may be the best approach, after all, they are not used to all the goodies VoIP offers. Personally, I find that as the right approach. You just skip all the drama trying to explain someone the different call flows. Keep it simple.

I will explain here how to accomplish that.

Fixing the Number of Simultaneous Calls per Extension

This is the easiest use case as FusionPBX has it out of the box. All you need to do is edit an extension, look for the limit max and limit destination fields and customize them.

Usually, the default values are okay you shouldn't change them.

Fixing the Number of Simultaneous Calls per Domain

The first approach will be to fix the number of simultaneous calls globally, this means if you have only allowed one call, then the second call will be rejected regardless if it is an incoming or outgoing call. The FusionPBX has by default a call-limit dialplan (disabled) but it doesn't work out of the box, so we need to fix it. Follow these steps:

1. Edit the caller-details dialplan, you will find it in the inbound routes and add a set line call_direction=inbound. If you are updating from an earlier FusionPBX release (earlier thant 4.4), it is very likely you won't have this dialplan. Here it is a screenshoot. Jus create it if you don't have it.
   
2. Go to the Dialplan Manager and enable the call-limit dialplan. You may want to make it a global dialplan (aka shared dialplans) if you want to make this a global think in your PBX.
3. Go to the Outbound Routes and for each outbound route you have, insert a line like this before the first bridge statement: hash inbound ${domain_uuid} ${max_calls} !USER_BUSY and again, you may want to make your outbound routes global
4. Go to the Dialplan Manager, edit the variables dialplan. Add the max_call variable like any other.

You are done, at this point, the number of simultaneous calls, regardless if they are incoming or outgoing, it is given by the max_call variable.

Fixing the Number of Simultaneous Incoming and Outgoing Calls per Domain Independently

Some odd scenarios may need a different number of incoming or outgoing calls. For example, you may give your customer six simultaneous incoming calls, and only two simultaneous outgoing calls. This is kind of more advanced stuff, if you really need this, don't hesitate to contact me for support.

Good luck!