Comment by jacquesm | Hacker News Reader

Comment by jacquesm | Hacker News Reader

I am so happy that coax bus based ethernet died. One of the hardest to track bugs for me involved a machine named 'chopper', an SGI box set up to monitor a bunch of other machines. Every now and then chopper would report one of the other machines on the network as down, and send out a page to an operator, which got quite annoying. We tried everything we could think of to trace the fault, replacing all the bits and pieces, including entire servers to figure out what was causing the problem.

Eventually the only thing left that we had not swapped out was a BNC 'T' connector at the back of the MAU of chopper itself, the one that was used to put it on the coax bus.

My buddy Jasper and I both looked at each other at the same moment around 4 am or so, bleary from sleep 'that can't possibly be it', let's swap it out. And sure enough that was it.

Apparently that particular 'T' connector had electrical capabilities unlike any other 'T' connector produced before or after. It managed to filter out 'ping' reply packets from the IP address of the server reported as down...

As someone who does temporary ad-hoc (read event) networking, having a coax standard for high speed, long point to point runs would be awesome - barring that, 100 or 1000baseT 2 port POE repeaters (read hub) would also be a boon - you could get nearly 1000 feet by powering from each end of the span.

Why not fiber? Its fragile, expensive, hard to pull, and not well suited to temporary situations, precut armoured fiber is very expensive - coax is fragile, but cheap and easy to terminate.

If you need to exceed that distance you can set up channel bonding over WiFi using multiple channels simultaneously and directional antennas.

Super-G is one implementation but you can also roll your own and on more channels giving you up to 300 Mbit on fairly long hauls.

http://en.wikipedia.org/wiki/Channel_bonding#Wi-Fi

Asus N56U claims to do this out of the box.

wifi wont usually span the distances I'm talking about, speed is not a huge concern, reliable distance spanning is.

Hm. Ok, I've done long-haul wifi with directional antennas over more than a few Km, but not at those speeds. What distances and speeds do you need?

I need to be able to span 500-1500 feet inside buildings and over complex terrain - a microwave shot is easy to do, but most of the stuff I'm doing is not that simple - worse off, most of the places I do this, have their own wireless networks that we are competing with for spectrum.

Ah, yes, if there are other transmitters nearby or in your target area then that complicates matters considerably, especially if you can't dictate what channels those use.

Another option then might be to have a spool of fiber and to use that instead. Fiber will happily go longer distances without much chance of interference or repeater issues. It's a more expensive option than copper but if you need to go over the easy-to-do-with-copper distance that might be a viable solution. Best of luck with this, it's funny how doing the last kilometer of a link can be harder than getting packets from here the other side of the Atlantic. Very easy to take infrastructure for granted.

You can probably do that with Ethernet extenders, depending on the speed you need. This one does 50 Mbit.

http://www.blackbox.com/Store/Detail.aspx/LinkGain-Ethernet-...

Find the right coax with the right impedance, then stick wifi cards on both ends and connect directly...

This can't possibly... I don't even... wait what?

Not the first time that's been considered. https://electronics.stackexchange.com/questions/103443/close... No follow-up on whether it actually worked though.

You can run antenna's a LONG ways from your wifi card by simply hooking up a VERY long wire. It's the same principle as your satellite dish.

This is also how you do testing of wifi in a way that won't interfere with outside signals.

It's the same principle as the old coax networks.

FYI there are a variety of MoCA products out there that support 175Mbps Ethernet over coax up to 300':

http://www.amazon.com/gp/aw/d/B008EQ4BQG?pc_redir=1414247414...

Thats actually kinda cool!

10BASE-2 was pretty annoying. Nothing was worse than losing your connectivity because someone else unplugged their machine from the string incorrectly.

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