SoftEther VPN User Forum

I have successfully connected the softether VPN on a windows 10 machine with ports forwarded on the router (nat traversal disabled). I have connected an android phone (ver. 7 galaxy s7) locally and via mobile network L2TP tunnel. I have an application loaded on the android phone that will connect normally via Lan (IX app from aiphone). When i connect via L2TP connection on the mobile network I receive a reserved IP from my windows 2012 server DHCP server. I am not able to connect to the app when I use the intercom or master station to ring the app though through the VPN. Any suggestions on why and what I can do to test why this is happening? i can see the mobile device server on the android via VPN but cannot receive calls.

I spoke with Aiphone about the app protocols and ports. I need to send SIP via the VPN and UDP packets to the android phone client. I noticed UPD acceleration was set to no on the session. Are there firewall settings I need to adjust on the local bridge or router forwarding? I believe the local bridge handles the transfer of data but am not sure exactly the right way to correct this. Any suggestions would be appreciated.

VPN connection with L2TP/IPSec doesn't have full compatibility with Ethernet.
Could you try to use L2 mode OpenVPN?