Actually the KNX interface makes use of IP connection. As such it is exposed to failures when local switches or routers fails. It would be great to add a direct Twisted Pair interface to the KNX bus. This was Home Assistant will be a real alternative to expensive KNX supervisors. The direct TP connection can be easily be achieved using USB sticks
Hi,
Although you still have solution to use computer/nuc with dual ethernet port and dedicate one at connection with the KNX IP interface with a direct cable 
Voted !
Vincèn
Yes, that’s another robust solution. Unluckily I have not a dual nic computer
Luckily ethernet ports are cheap.