I'm in a similar situation to phirk, attempting to move an SSDP implementation to Network.framework. It's mostly working except for the unicast responses from devices in response to M-SEARCH not being surfaced via the receive handler. All the multicast traffic is appearing as expected. I've had a snoop on the network traffic with Wireshark and I can see the unicast responses arriving from the other devices on the network but for whatever reason the response never reaches the handler code. Having been bitten by some of the defaults in Network.framework, I've tried explicitly setting the "disableUnicast" argument in the NWMulticastGroup initialiser to false (also true just in case something's being reversed somewhere) and nothing seems to have an effect. Is there a way to get the port number associated with the socket NWConnectionGroup is using so I could try setting up an NWListener to work around this issue?