GIGASET DX800A cannot register after V.16

[Armandos]

Hello I have a GIGASET DX800A which was registering fine. After upgrading 3CX to V16 onwards it does not register anymore.

However, we have a pretty strange setup.

The 3CX is on LAN with ip 195.200.64.22 (I know it seems a public ip but this is INTERNAL LAN for VPN reasons)
The DX800A is on another LAN with ip 192.168.1.6

Those two LAN are connected with VPN SITE-TO-SITE connection which works perfectly.
All mobiles connect perfectly from 192.168.1.0 to 3CX without any problems.
Paswords, addresses, ports credentials etc. have been checked and are correct.
Allow extension from WAN is enabled.

Any help?

Thank you in advance

 

[JohnS_3CX]

Hi Armandos,

The model is not supported, so there is not guarantee that it will work.

Beyond that I would recommend to either replace it with a supported model, or look at logs or captures to understand what is happening.