accessing serviio on different subnet

Hi everyone,
I'm looking for some slightly technical help and I have a bit of a strange setup, the questions are mostly about how devices connect to serviio and how it responds, particularly with multicast involved.

I have a mikrotik router at home which is set up with multiple lans. The serviio machine is on the lan along with the clients at the moment, but I want to split the lan into wired and wifi segments (I had to merge the segments to get access from one of my tvs but I want to fix that soon). I have tested moving serviio to a completely separate subnet and successfully have it showing up to devices and I can see that this is to do with announcements made on multicast address 239.255.255.250. When a device sees the serviio box, it cannot then view the library. I assume that the client accesses serviio directly at this point but it fails. I have a suspicion that this is for one of the following reasons

1. Serviio expects the client to be on its own subnet and ignores it (I have seen something about this related to minidlna so assume it may be something todo with how dlna works) - If this is the case, does this mean serviio has to be on the same subnet in order to respond to unicast requests?
2. My multicast setup is wrong and there are some other multicast addresses that need to be accessible - I have not done anything special in my router to allow connections over 239.255.255.250 so I assume this is not the case.
3. Serviio is successfully broadcasting to the multicast address, but my router is not passing anything from the clients back, meaning its not possible to set up a connection.

Does anybody know of a good description of how a dlna connection is setup? It must start with the client or server sending an announcement to a multicast address, but what happens when a client wants to start talking to the server?

I could of course leave my serviio machine on the lan but I want to get my network setup neatly and theres also the educational part as I don't like not understanding how things work.

Regards
Pete
UK

Had to read that a couple of times, but I think I understand the setup. As for why, it's not working, I think only point 1 stands a chance. You should be able to check that when enabling debug logging.

The strange thing is that (afaik) the DLNA protocol is a really simple one. Devices broadcast information about the services they support or export, and from there it's just http (indeed, using tcp). So if your tv is turned on, it will broadcast a request for some media sharing services. Serviio will respond, and your tv shows Serviio. That's all the multicast. From there on, the tv and Serviio are using tcp/ip.

Does your router block tcp/ip routing over the multiple segments? Maybe blocked in the firewall?

Note: of course, I'm no guru at all, it's just something I noticed when playing with wireshark. Wanted to build a simple site where I can select my movie (listed from Serviio) and play themon my tv (use the site as remote control).