3CX users Connected Behind a VPN to access 3CX application on PC only

[gregory.b]

Hello,

I have a Client in Version 20 installed on Premises on a Server.

The FQDN of the 3CX is resolved by its Firewall through Internal IP and is working fine in Office and outside Office Via FQDN.

Today the Client want to Use VPN for It's Uses that are not in Office.

The VPN users will have a different IP Range which has been Whitelisted in 3CX.
However, it seems that it doesn't work via the VPN which is configured as same as the 3CX.

Can Someone help on how to make 3CX work via a VPN.

IMPORTANT NOTE : we are not talking about Any Physical phone.
Only Application on PC will be used.
Not talking about SBC

What are the steps or configuration required to make it work on a 3CX Version 20.

 

[NicholasP_3CX]

When they connect via VPN to which IP Address is the 3CX server being resolved to? The external IP address or the internal IP Address?
Does the VPN internal network these clients connect to internally have access to the PBX server?

 

[gregory.b]

When they connect via VPN to which IP Address is the 3CX server being resolved to? The external IP address or the internal IP Address?
Does the VPN internal network these clients connect to internally have access to the PBX server?

Hi Nicholas thanks for the reply.

So it is resolved by the internal IP of 3CX

yes they have access to 3CX internally in office.

 

[NicholasP_3CX]

Yes, but does the different network the VPN users connect with also have access?

The VPN users will have a different IP Range

This IP range will also need to have access to the 3CX server. Check if your firewall/router/switches are blocking this access.

For a device not to connect means something somewhere is blocking it from connecting.

If you do a traceroute (with hostname and IP) from your PC which is connecting, do you reeach the PBX server?

 

[VoIPTools]

Is the VPN a software application running on the 3CX server?