Branch offices connected via VPN and 3CX (Free version)

[mmaenpaa]

Hi,

We are thinking about using 3CX. At this point I am only interested in calling phones in our offices. I was wondering if this scenario would work in principle with FREE version (if this goes well I might get the courage to consider outside calling with commercial versions)

Main office,192.168.0.X (external IP is static)
3CX server, 192.168.0.5
Phone0001 192.168.0.10
Phone0002 192.168.0.11

Office1, 192.168.1.X (external IP is dynamic)
Phone0101 192.168.1.10
Phone0102 192.168.1.11

Office2, 192.168.2.X (external IP is dynamic)
Phone0201 192.168.2.10
Phone0202 192.168.2.11

(and so on...)

Each office is connected to Main office via VPN. VPN tunnels are generally very stable (dyndns is used on branch offices).

These features are required:

1. Calls in Main Office between phones
2. Calls between Main office and Office1(and 2 etc.)
3. Calls between Office1 and Office2
4. Calls in Office1(and 2 etc.) between phones
5. 10 or more simultaneous calls

I understand that we could do this via VPN "internally" or go "externally" and use port forwarding in the Main Office firewall.

Best Regards,

Markku Mäenpää

 

[Discovery Technology]

Hi Markku,

I would recommend a single 3CX Server for your setup, utilising the VPN tunnels for your inter-office calls. this would be a lot more secure as well as a lot more reliable.

Be sure to utilise the outbound proxy setting in your remote handsets (define the 3CX Server IP address here) and enable "PBX Delivers Audio" for each remote extension.

This would support your proposed network design.

Unfortunately your last requirement won't be possible with the free version though as it only supports a limited amount of simultaneous calls. to support up to 10 calls at a time, you will need to purchase a 16-call license. Mind you, this is still excellent value, considering it will save you on purchasing three separate phone systems and a whole lot of engineering time installing such a setup.

I would recommend purchasing a license once you can see the phones are able to call each other and easily transfer calls between the sites.