I am new to the world of boating electronics.  However I have more years experience than I care to admit doing network security.  I see that a lot of the electronics are 'networkable' via ethernet and see one can add 'switches' to connect multiple devices together for enhance functionality and sharing some info.  Does anyone know, in general, is it TCP/IP running over those ethernet cables and through that 'switch'? Or is it some proprietary manufacturer specific protocol?  Are the 'switches' traditional switches or hubs, or again something proprietary?  Just curious at this point.

 

Thanks,

Joe

Get one and plug WireShark in and let us know what you find out!

 

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https://en.wikipedia.org/wiki/NMEA_2000

I don't think it is TCP/IP given the data rate spec of 250kbps and 50 device max. But maybe some mfgrs are also running their own conversation over the same hardware as the NMEA bus. The article above will probably lead you to the protocol details.

 

https://en.wikipedia.org/wiki/DeviceNet

Looks like NMEA is all done at the data link layer, which makes sense for a closed network, no need to anticipate routing. But I did see mention elsewhere of port 2112, which is odd.

 

From looking at the humminbird switch, it's custom cabling that looks just like the devicenet connectors. Probably a standard chipset for a dumb switch wrapped in a waterproof box with marine connectors vs an RJ45. 

 

Here's a video of a guy that networks garmins that have Rj45, using a netgear switch. IMO if one spends $2500 bucks on livescope, skimping out on the switch and putting a netgear in a tupperware box is just a terrible choice. But it is clearly possible. 

 

 

 

Some detail here too.

https://www.researchgate.net/publication/259337915_NMEA_Communication_Standard_for_Shipbo

ard_Data_Architecture_NMEA_komunikacijski_standard_za_arhitekturu_podataka_na_brodu
 

I can’t speak for every brand but Humminbirds use standard Ethernet and tcp/ip.  I don’t know what speed they run at.  They use different cables with M12 connectors.