Okay, let's see if we can get it working using broadcasting rather than multicasting. To do this, close down tRio and change the "send-method" value in trio.xml from "multicast" to "broadcast" (your broadcast-address value looks fine).

Once we have this working we can try and figure out why multicasting isn't working on your network.

On your multicast address query, to be honest I can't remember why that specific address was chosen - might have got it from some sample code somewhere. But any address between 224.0.1.0 and 239.255.255.255 should work. Even if another application is using the same address, the chances of them using the same port numbers (from 19682 upwards) is remote.

Cheers
Paul