Linking PBX

[Frankie358]

Hi

Ive setup 5 PBX in 5 locations. All have separate extension ranging from 300 to 320. I now need to set them up so that an extension on say PBX in location A can call an extension in location B. How would i go about doing this?

 

[EasyBB]

Ive setup 5 PBX in 5 locations. All have separate extension ranging from 300 to 320.

Are you saying you have same extension numbers 300-320 in all 5 locations? It's not going to work then.......

 

[Frankie358]

No all phones have separate extensions.

 

[EasyBB]

No all phones have separate extensions.

Ok in that case you will require either one of these:

• site to site vpn between all locations (need appropriate IP subnetting)
• pbx to pbx vpn between all boxes
• port forwarding enabled at each location for sip and rtp

I would also have a separate profile for the remote stuff.

Then refer this page: https://freeswitch.org/confluence/display/FREESWITCH/Sofia+SIP+Stack

Syntax
Call an extension on a Remote SIP Server
Basic form:
sofia/<profile>/<extension>@<remoteserver>

Example 1:
sofia/$${profile}/$1@example.org

Example 2:
sofia/foo/0@sipphone.com

Where <profile> is the name of one of the profiles defined in sofia.conf.xml. By default, there is one profile defined as name="$${domain}", where the $${domain} variable is defined in freeswitch.xml, and defaults to mydomain.com.
Therefore, if you have not changed these config files and are dialing an extension on a remote server, the config would be
sofia/mydomain.com/<extension>@<remoteserver>

To list all profiles defined, type sofia status on the CLI.
Call a locally registered endpoint
Basic form:
sofia/<profile>/<extension>%<localserver>

Example 1:
sofia/$${profile}/$1%$${domain}

Example 2:
sofia/foo/101%192.168.1.1

where foo is the SIP profile, 101 is the userid of the registered endpoint, and 192.168.1.1 is the IP address of FreeSWITCH.
If your SIP profile name is set to your domain, or the domain attribute is set in the profile (e.g., <profile name="internal" domain="$${domain}">), you can originate with the following:
sofia/<profile>/<extension>

And fore-go the domain when dialing local extensions.

 

[Frankie358]

Sounds like this may be just a little over my head. I'm new to this to be honest. I didn't really explain the setup particularly well either.
So the setup is the same in each location. 1 x Router 1 x NUC running proxmox and FusionPBX 1 x Grandstream (for PSTN outbound calls if the two sip channels are being used. 3 x Cisco phones. This is the same setup on 4 locations but I also have 1 location Using a Draytek PBX with 3 phones. The customer has requested that all phones can cal each other. To be perfectly blunt I really dont know what I'm doing and have basically told them at present I cant achieve this. It would be great for the customer if I was able to put this into practice for them.

 

[EasyBB]

Sounds like this may be just a little over my head. I'm new to this to be honest.

I am not an expert at this either. Just take this as an opportunity to learn something more. You may experiment with the concept first by spinning up couple of VMs on the same LAN and get calls between them working; then move one VM to another internet connection and think how would you reach the other box.

To be perfectly blunt I really dont know what I'm doing and have basically told them at present I cant achieve this.

The easiest way out of this situation is to install a single FusionPBX on a VPS and have all locations register to it. You can have 5 domains, if location separation is required.

 

[Frankie358]

Not really an option to be honest its already in place and running.

 

[SilkBC]

I am new to FusionPBX myself, but I was able to achieve something similar on two FreePBX systems by connecting them to each other via SIP, then creating outbound routes with dial rules that sent certain extensions out a specific trunk. I would imagine something similar could be done with FusionPBX.

In principle, it's not much different that when you register your PBX to a provider's SIP trunk.

 

[EasyBB]

then creating outbound routes with dial rules that sent certain extensions out a specific trunk. I would imagine something similar could be done with FusionPBX.

Absolutely correct; this was my third bullet point in the earlier post. This would appear daunting the first time, after that just becomes practice. I do prefer box-to-box OpenVPN these days though.

 

[Frankie358]

Would anybody have any clear instructions on how to do this, (sorry for asking but I'm just bumbling around, I dont; really know what to do)

 

[Kenny Riley]

You're saying that you have 5 PBX's in separate locations with extension numbers ranging between 300-320 with no overlapping extension numbers between the boxes, correct? If this is the case, that means you only have about 20 total extensions between all of these locations combined.

If this is the case, then the correct answer to your problem is to stand up a single VPS FusionPBX install and register all of the locations to it. As EasyBB said, if you need to separate them, you could simply create a separate tenant for each location then add a dialplan entry to each tenant to allow for extension to extension dialing between them. (There are tutorials out there for doing this)

You are saying that isn't an option because they're already up and running?

That's really not an excuse to not architect this in the correct way. You're migrating 20 extensions, not 200. You could spend a couple of hours building out a new FusionPBX install with the correct call routing scheme for each location prior to the cut over and complete about 95% of the work without interrupting anything in production. You could also buy a few testing DID's, and test inbound and outbound calling on the new PBX for all locations prior to the cut over day to ensure things are working the way that they should be.

On cut over day, all you have to do is reprovision phones to register to the new FusionPBX box, point your carriers to the new IP, copy over voicemail and greeting files, and you're done. The downtime here would be minimal.. even non-existent if you performed the actual cut over after business hours -- which is what I would do.

Any other solution is simply over complicating things.

Yes, you could configure site to site VPN's between all locations, configure a gateway for each location on every PBX, configure outbound routes to match extension numbers to send calls out to the correct gateway, etc... But why? That's a ton of unnecessary moving parts.