Thank you for your swift feedback Eskimo!
According to that I should now be able to use NWConnectionGroup (not NWConnection, since it wasn't deisgned to handle multicast, correct?) to send SSDP packets to the multicast IPv4 address 239.255.255.250 (already tried it in Playground and sending the packet works) and the receiveHandler should then be able to retrieve and show the unicast replies of each answering device (I couldn't get that to work yet).
Could you confirm, just so I know I am on the right path?
Many thanks again
nicolaswehmeyer
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