Seems like everyone's got a product for putting NMEA
data over IP (over 802.something) these days. I notice that IEC 61162 part 4 specifies NMEA-0183 over "ethernet". It costs CHF280 to buy the document (so I won't be doing that for my freeware project) but the downloadable index
suggests that it is specifying UDP multicast as the transport mechanism.
Are any manufacturers actually using this standard? All the products I've seen translating nmea-0183 to ethernet/wireless seem to use either tcp or udp broadcast with a variety of different ports
. Nothing using multicast.