Garmin Network - Is it actually Ethernet?

[dabigkahuna]

I've been reading through the Garmin literature and see that Garmin refers to it's network as "Ethernet-Like" capable of "Ethernet-Like" speeds. Is this simply sales talk or are they actually using ethernet? Has anyone tried using ethernet accessories (like hubs?) instead of Garmin proprietary hardware for hook ups?

[deepanchor]

Looks like Ethernet to me. Plugs are the same in my opinion.

[TroyBoy30]

i wouldnt try to use a non garmin ethernet cable though

[deepanchor]

i wouldnt try to use a non garmin ethernet cable though

I totally agree.

[LWINCHESTER2]

Wouldn't bother me a bit. Near certain that Garmin ethernet is standard, off-the-shelf ethernet.
Garmin published color code of the pinouts are:
1 White/Orange Tx+
2 Orange Tx-
3 White/Green Rx+
4 Blue
5 White/Blue
6 Green Rx-
7 White/Brown
8 Brown
This is the industry standard color code for RJ-45 ethernet connector based on EIA/TIA T-568B specification. The cable length spec is 100m, again standard ethernet. They also provide directions for making your own cables from bulk cable. It is of note that their directions are for making a "cross-over" cable. Big difference in a standard ethernet cable and standard crossover ethernet cable. There is a side A and side B for crossover cables. The wiring color code is different for side B so that the transmit/receive is matched up. This makes it look like the Garmin network is not "auto-sensing". Auto sensing equipment look for the signals on the wires and adapt to it. This is a little on the ancient side. Ethernet actually only uses four wires even though nearly all standard cables have 8 wires. It uses the Orange and Green pairs, pins 1,2,3, & 6. When making a cross-over cable the green and orange pairs swap positions on one end of the cable. The blue and brown wires are not used.

http://static.garmincdn.com/pumac/Marine_Ethernet.pdf

If you've tried an off the shelf ethernet cable and it didn't work, it would be because it was not a cross-over cable and both ends were wired as side A. The industry has almost totally standardized on cables with both ends wired as side A and in situations where cross-over is needed use auto-sensing and adapt rather than having to use a different cable.

The significance of this is that some attention has to be given to which cable to use for a particular connection. I haven't studied Garmins setup but based on the ancient look of it, connecting one unit directly to another unit would require a crossover cable and connecting 2 hubs together would also require a crossover cable. It's possible they use a crossover cable all the time for all connections. They could do that if their hubs were auto-sensing. So if you were going to use a non-Garmin hub it would need to be auto-sensing. If not, then the cable would have to be a standard cable, not a crossover cable.

Probable clear as mud now.

[dabigkahuna]

No, your post is actually pretty darn clear! ;)

Ethernet actually only uses four wires even though nearly all standard cables have 8 wires. It uses the Orange and Green pairs, pins 1,2,3, & 6. When making a cross-over cable the green and orange pairs swap positions on one end of the cable. The blue and brown wires are not used.

So do you believe that Garmin's network also only uses 2 twisted pairs? If so, that would be very good news for my application.

[TroyBoy30]

actually someone just posted on THT to use a temp cat5 cable to troubleshoot issues and it worked

[hays47]

When I was networking my 1040 and echomap 70. I used a standard cat 5 cable to see if it would work until a Garmin cable got here. It did work for testing purposes.

But did not operate normally. In that the GCV 10 would not turn on with the Echomap. The 1040 had to be on. Once Garmin cable got here network worked as designed.

[LWINCHESTER2]

When I was networking my 1040 and echomap 70. I used a standard cat 5 cable to see if it would work until a Garmin cable got here. It did work for testing purposes.

But did not operate normally. In that the GCV 10 would not turn on with the Echomap. The 1040 had to be on. Once Garmin cable got here network worked as designed.

This would mean that the ethernet is on pins 1,2,3 & 6. I don't have the complete technical pinouts for Garmin so it would be guesswork as to how and where they put the wake-up signal. Wakeup can usually be done with one wire since the unit already has ground available. I would have guessed that if they put the wakeup in the CAT5 cable that the would have used the specs for POE, power over ethernet. But if so, it should have worked with a standard CAT5 cable. The only way to know for certain is to have the complete pinout specs.

[BassTracker175]

Good info!

[D Johnson]

Networked 30 plus schools before I retired and have put on thousands of these connectors. Even have the tester some where to check that everything is right. Been wanting to take a close look at Garmin's cables with the tester just to lazy to look for it. Suspect my son has it anyway. Each of the twisted pair has a different twist rate that is how they deal with interference. When you have a 400 foot length of cable in the overhead and there is lights and fans and AC and all the other stuff up there good CAT5 and now CAT7 does a good job of protecting the data. Don

[LWINCHESTER2]

Garmin's network cables are crossover cables. As far as I can tell all the units ethernet connections are auto sensing and will adjust to normal or crossover cables. I've tried standard CAT5 on several and they all worked. Two other things make Garmin's network cables different. Look at the RJ45 connector on the cable. The ground shield is continued to the RJ45 connector metal housing and makes contact to the unit. The other thing is that it is "mostly" waterproof. You may find out it's not if you change out equipment and cables much as it is easy to loose the O-ring and not realize it. Way back, I did have trouble getting a PS21 to turn on through a cheap 12v hub using a standard CAT5 cable. Not exactly sure why, but I attribute it to not using the grounded RJ45 and cable. I picked up a couple of used GMS10's off ebay, so I'll just stick with the standard Garmin stuff.

Something overlooked by trying to save a few dollars. If you have a network issue and the network is not all Garmin, good luck.

[Phoenix919]

Yes Sir real Ethernet. You can see IP addresses if you plug into a port expander with a sniffer tool.