Limits for accessing Minimserver

[Regade]

Dear Community,

is it possible to regulate the accesses for my mediaserver, that only my PC, Streamer and mobile devices are able to "see" the server and play the music?
I think i may can regulate the accesses by turning the firewall of my NAS on. Afterwards i can limit the access by opening the ports only for my devices (IP adresses) for the protocolls (UPnP, DLNA).

I figured out UPnP is 1900 and the "Synology DLNA server used TCP ports 50001 and 50002". But idk. if 50001 & -2 are for the Synology specific server or something else?! And "minimServer has a setting for the tcp port number to use, default is 9790"

So do you know if its a) possible and b) which ports are used for the processes / minimserver that i can set my firewall up?

Greetings!