Multi-Wan setup - one for trunk, other for external clients?

[nobody]

I have a system where the trunk (12 lines) is connected using a SDSL line. Also external SIP clients and phones using the 3CX tunnel are using the IP address of this link. This was not a problem until recently when suddenly more external clients need to use the PBX from external locations. Now I have something like another 16 external clients conncted. in addition to the trunk. The SDSL line is 2Mbit/s, which will not be enough if everyone is in a call (assuming about 100kbits/s per call). The Agents use the webclient in their remote-Desktop environment to remote control the windows client running on their local PCs.
The company uses a 100Mbit fiber connection for internet and VPN. All clients connect using a VPN.If the VPN is established before the 3CX windows client is started, the VoIP traffic will be routed through the VPN, but it seems that when people are using their remote desktop connections, the phone quality gets worse then it could be if it would not be routed through the VPN tunnel.
I would like to use the fiber connection for the clients without routing the VoIP traffic through the VPN tunnel but to the public IP of the system.
On the firewall, I am able to send only traffic to the VoIP providers IP adresses throught the SDSL line. Any other trough the fiber connection. But I have no good test environment to check this out before, so I would like to know if this is either a supported configuration or if anyone has experience with a similar setup?
Also, how can I force the Windows client to connect to the external IP address of the PBX and not use the VPN? I could block access to the internal IP of the PBX through the VPN tunnel, but will this be enough to make it switch to the external IP and use the 3CX tunnel?

 

[cobaltit]

You could do a variant of the multiple internet gateways method outlined here:

https://www.3cx.com/blog/docs/network-configurations-supported-3cx-phone-system/

Otherwise just switch your trunk and clients to g.729

 

[nobody]

Thanks.
What I want to do is nearly the same scenario as the "Multiple internet gateways", with the difference that here is only one gateway which manages the distribution of the traffic to multiple WAN interfaces. Therefore I assume my plan will work. But if anyone had done similar that would be good to know if I run into troubles.

 

[cobaltit]

Well instead of trying something new, just do g.729 then

 

[nobody]

Ok, I did change the setup like I initially wrote. Works fine - and call quality has improved.

 

[cobaltit]

Good deal, thanks for the update