How to make Seamless multi PBX system dialing

Dear All ,

I am a not advanced but not a completely clueless user /Admin.

I have 4 PBX’s (3 IP PBX and One Analogue ) . all 3 IPPBX of FreePBX of course are connected with IAX2 Trunks(and VPN of course ) and the analogue PBX is being connected via an analogue card on one of the extensions of it into the IP PBX ,

So that I want to know is how can I set up the 3 PBXes to have seamless dialing for example I am at PBX 1 and extensions have numbers from 100-150 , other PBX has 300-350 and the other PBX have 200-250 ,

How can I configure the Dialing rules to allow me to just press the 121 for example and go to PBX number 1 from PBX number 3 with out any prefix designating that I need to be routed to PBX number 1 ?

Thank you in advance

Le Test

You could use outbound routes and match pattern


To the appropriate trunk,

then rinse and repeat.

Dear Sir ,

Can you be a bit more specific with what goes where ? please ?

Thank you in advance

PBX 1 with extensions 100-150 needs an outbound route for each PBX it’s connected to and on the other PBXs you need to do the same.

To route calls from PBX 1 to PBX 2 e.g., click Outbound Route, under Trunk Sequence for Matched Routes select the trunk to PBX 2, then click Dial Patterns tab and under match pattern put a string in there for the range of extensions that match what you have on PBX 2.
E.g If it’s extensions 200-250 then 2[0-5][0-9].

Do that for each route you need and for each PBX.

Hope that helps.


You REALLY need to read the WIKI a few times, that is why it is there, and I can assure you all those “specifics” are very well covered :slight_smile:

Dear Dicko ,

Yes I know the Wiki exists , but sometimes you need someone to explain it a bit differently , in order to understand and all have something in case of followup questions.

And I did read the wiki and I had a question so I came to the forum :smiley:

I am very very glad that people are helping i really do.

but I hate wasting peoples time so yeah. I’ve read the wiki and i still had questions :slight_smile: sorry for that :smiley:

You build trunk between the PBX’s. Then you need to make a prefix that will tell the PBX what trunk you want to send the call to.

You build trunks between all boxes and in your outbound route you use as a dial pattern the extension range that each box has. Finally you setup the outbound routes as a intra company route to preserve the proper cid.

Dear All ,
as “posi21” Said I did that exact thing given a prefix for every PBX but The numbers wore getting too long ,
so I asked how to make it with out the Prefix ,

so as other and astbox said
make infra company trunks , give them different extension numbers(subnets) (PBX1 is 100-150 , PBX2-200-250 , PBX3 300-350)

and make the appropriate routes as defined above from mister “avayax”

Now the Last problem that I have is to make an IVR that will be on the Incoming route from the Analog PBX to allow me to dial to the other PBX’s

But I am still consulting the manual before asking any one for help due to “time is money” or “time is Myocardium” as Cardiologists say :smiley:

Thank you everyone for your Input and Help very much appreciated

For the analogue pbx look at Disa ?

So you have your IVR on the analog PBX?
Is that PBX trunked to all of the FreePBX​ boxes or just one?

Dear Sir,

Well is a bit more complicated.

The analogue PBX has an extension close to my FreePBX mashine so i ordered an Analogue card with a FXO & FXS ports (in layman’s terms one port accepts a line and the other port creates an extension) and i put the FReepbx box in between the normal analogue extension
So the idea is to give the ability of the Analogue PBX caller to call up the Voip System and being able to call the other PBXs

And i hope to do that with the IVR when you ring up the extension that is connected on the Freepbx you will be given 2 options to call the local extension or to call any remote extension like 200 or 300 etc

I don’t know how efficient and how correct this method is.

But unless i completely change the old analog PBX with FreePbX and Voip phones or a lot of ANALOGUE cards i think this is an okay-ish solution

If you have any other ideas for this application i would be glad to hear them

Thank you in advance

I have no idea what Disa is… :cry: care to elaborate?

Disa is direct system access it provides a dial tone to your incoming analogue extension that either direct or via a pin provides dial tone from which your one/line can call any extension on freepbx also if required externally

Does your analog PBX have no digital capacity whatsoever, such as H.323 or ISDN PRI?
My guess is it does, what PBX is it?

If your analog PBX is trunked to one of the FreePBX boxes via PRI e.g., there should be no problem accomplishing what you want.

You can leave all analog sets connected to your old PBX, and send all calls from analog phone to an extension on one of your VoIP boxes, to one of your FreePBX machines directly, which will route the call wherever it needs to go.

You don’t need the IVR solution then, which would just introduce an unnecessary step for the caller.

I also have my old legacy PBX, with about a thousand analog phones connected to a FreePBX box with IP phones.
Works very well.

Dear sir,

Nice, i will have a look and see if that does the trick for me :slight_smile:

When/if you give up trying to do it yourself, hire a consultant to help you. it will cost you a lot less in time.

Dear Avayax,

Good idea but i highly unlikely because the PBX is 26 years old (and i don’t know for how long before the purchase was in the market) is Panasonic brand but i have no idea for the make(model) at the moment i know it handles up to 40 extensions and 10 external lines has backups and other tricks but the guy how initially programed it is gone (maybe dropped out of the jib entirely and the company is also lost) so is difficult to even get people to see what is going on

Plus even if there is such possibility i will be unable to utilise it because i am quite far from the PBX it self and running new wiring is a hustle.

But non the less it would be a life saviour

In case I found out that there is a possibility do i need any other hardware

Dear Sorvani,

Yes in case of mission critical systems yes you get hired help to keep your mind at ease i hate petting systems,

But this is for me to get better at it and find out how powerful this system can be (from what i see and hear is a rock solid system) but this is just as a small project i have for my self.

In a production environment that time is money and myocardium yes I would never do it my self because i would definitely do a LOT of things Wrong

But still thank you :blush: for your input.

What model of Panasonic. I know a bit about them.