According to your description, your software might be using Broadcast messages instead of Multicast.
If indeed Broadcast messages are being used, then you can:
- Update your RUT240 to last firmware version
- Then from its "Services -> Package manager" menu download "UDP Broadcast Relay" package
- Finally from "Network -> Interfaces -> Lan" menu enable "UDP Broadcast Relay" option and check if that resolves your issue.
Meanwhile, if indeed Multicast is used by the application, then you would need to wait for next upcoming 7.2 firmware version, since only it would introduce IGMP proxy service (as a downloadable package), which would allow to receive Multicast packets from WAN.
In any case, there should not be a need to use Multicast/Broadcast in the first place. Even though that might be desirable in large scale deployments, smaller solutions are restricted because of this for no reason. You should be able to ask your equipment manufacturer (Alfen) to provide solution for you, so that you could connect to your equipment via simple TCP/IP communication via IP and Port number. That would definitely allow you to reach your equipment remotely without any restrictions.