Hello world,
I'm new to these forums and an Expedition n00b, but I'm an experienced TCP/IP network engineer and have a solid understanding of NMEA2000/NMEA0183.

We're refitting our boat telemetry and on a mission to kill unreliable point-to-point serial comms. This stuff is so prevalent in the boating world, but so long obsolete in the IP world.

TL;DR: We  have an IP-first design philosophy with a modern TCP/IP network on board, including ethernet swtiching, routing, nat, starlink, cellular, wifi 6, udp broadcast relay, mdns, etc, capabillities. Naturally we also have a mature N2k instrument network, including B&G Zeus2, Zeus3s, Actimar and so on.  I'm seeking community recommendations for a robust N2k/N183 ➡ Ethernet gateway (not wifi, and not serial)

Why?
We have different client apps that require different feed versions due to various constraints. For example, Expedition ideally works with bidirectional NMEA2000 via TCP, and this is running both onboard, and potentially on an onshore computer via Starlink. Handheld devices running https://www.zapfware.de/nmearemote/ connected off-boat via Starlink need NMEA0183 via tcp, and we have one guy in Colorado using this for now. Any other onboard wifi crew or telemetry device uses NMEA 2000 via UDP (which is broadcast so has unlimited connection capacity).

Plus, I need to be able to run tests against any of these ports, use OpenCPN, canboat, etc. So we need multiple ports and the ability to receive/send NMEA 2000 and NMEA 0183, ideally via open protocols, but it seems the N2k over IP world is shockingly proprietary.

What have we tried?
The closest thing on the market that meets requirements is the Yacht Devices YDEN-02, an amazingly tiny embedded linux device which works well... when it works. The protocol "Yacht Devices RAW" is proprietary but is widely understood by various endpoints. Yacht Devices support has been exemplary.
...but....it is grossly underpowered and the software is half baked.
- It has severe performance/capacity limitations that cause it to stop responding due to resource starvation.
- Advertised with up to 3 simultaneous TCP connections on two TCP ports, plus unlimited udp port connections (of course, since its broadcast). This should mean a total of 6 tcp connections, which I found crazily limited but would be adequate if accurate.
- In actual sailing conditions, this thing is unable to sustain more than two connections and, worse, existing connections drop/hang when new ones are attempted. I found this out the hard way in last week's Noakes Gold Coast race in Australia. This makes it undeployable because you can't know when it might become overloaded. The result was that the onboard Expedition computer's connection kept dropping intermittently - the last thing you want to happen when 70nm offshore.
- It offers zero diagnostics, not even a list of incoming client connections, throughput, or any kind of statistics. You can't even ssh to it to look at its internal logfiles.


What have we researched?
It feels like most products on the market are just repackaged serial converters with similarly half baked bolted on SOC linux systems. This weird "3 servers" or "2 connection" limitation stuff is so foreign in a world where even a humble Raspberry Pi can easily handle hundreds of TCP socket connections.
Anyway, here's what I've researched to date:

Yacht Devices
- Manufacturer confirmed 2 stream limitation of yden-02.
- Have a new version about to be released, yden-03, with more memory and CPU grunt.
- I've contacted Justin of Yacht Devices Australia who has been excellent: No solution until then.

Actisense
- Offers the relatively new WGX-1
- Wifi only, no ethernet
- Same internals as the NGT-1/NGW-1, but is at least now configured via web interface
- Limitation of 4 clients when in AP mode
- Limitation of three server ports
- Unclear from manual whether NMEA 2000 and NMEA 0183 can be streamed simultaneously.
- Unstated concurrent TCP connection limit
- I am not a fan of the highly proprietary NGT-1/NGW-1 and their non-ARM compatible drivers although I know from reading the forums they are a favourite here and arguably has the best NMEA 2000 protocol implementation.
- I've reached out to Actisense to ask these and other questions.

Digital Yacht
- Offers LANLink NMEA to Ethernet gateway
- Is a legacy device that outputs NMEA0183 only.
- The N2k "version" adds a bolt-on NMEA2000-NMEA0183 iKonvert box that has to be externally wired to the LANLink serial input, so a massive kludge.
- Manual states TCP client limit of 5

B&G Zeus
- Fortunately we configured the Zeus built-in NMEA0183-over-IP streaming as a reliable backup for the race, which we ended up using in Expedition when the YDEN-02 failed.
- This doesn't do NMEA2000 and is read-only to clients.
- Does not appear to have connection limitations and never stalls.
- Does not support the full range of sentences/PGNs.
- If they ever upgrade this capability, that would be nirvana, since Zeus is redundantly connected via Ethernet and Wifi, and it has plenty of performance. The best part is no part.

Signal K
- Obviously the SignalK movement is simpatico with everything I'm talking about here, and extremely cool technically.
- However, the crew is non-technical. I don't really want to have to deploy an additional server and/or docker container, creating a heap more complexity onboard.
- I would prefer a discrete, dedicated hardware device that just works. If the YDEN-02 worked as advertised, it would do the trick and I wouldn't be posting here.


What am I asking?
Does anybody use and recommend an ethernet connected NMEA 2000-over-IP protocol converter with decent performance headroom and reliable operation please?


Thanks for reading!
- Marc

Last edited by ed209 (8/01/2025 11:09 pm)