
Building a 10BASE5 “Thick Ethernet” Network (2012) - cyanoacry
http://tech.mattmillman.com/projects/10base5/
======
jacquesm
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...

~~~
Aloha
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.

~~~
willidiots
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...](http://www.amazon.com/gp/aw/d/B008EQ4BQG?pc_redir=1414247414&robot_redir=1)

~~~
Aloha
Thats actually kinda cool!

------
jbert
It's pretty interesting to read into the original "broadcast" ethernet specs.

The "thick yellow wire" and the "coax" both had a single broadcast domain for
all devices on the segment. You then linked segments with a bridge (so you
could scale networks).

Some things I find interesting about them:

1) The idea is based on radio broadcast (ALOHANET). Since you're using radio
broadcast there, a single collision domain makes sense.
[http://en.wikipedia.org/wiki/ALOHAnet](http://en.wikipedia.org/wiki/ALOHAnet).
The protocol is best understood as "room full of people shouting at each
other". Don't start talking if something else is, and if two people start at
the same time, you both back off. Simple as that.

2) If two nodes try to transmit at the same time, you get a collision and both
retry. The spec has a random retransmit timer to avoid immediate (and
perpetual) recollision. Requires fair nodes...

3) The max cable length and packet size and related via the speed of light (in
copper):
[http://www.wildpackets.com/resources/compendium/ethernet/pro...](http://www.wildpackets.com/resources/compendium/ethernet/propagation_delay)

4) It was (semi-)reasonable to use a "vampire tap" connector to dig through
the insulation and into the core of a the "thick yellow" copper cable. Just
don't wiggle it and cut the copper (or introduce too much of an edge and get
signal reflection and hence more collisions).

5) When you had a copper connection between all the ports on your network, an
etherkiller really _meant something_. (A cable, mains plug on one end, coax
connecter on the other. Plug in and fry every network card on the segment).
RJ-45 etherkillers are single-target. Pah.

~~~
kjs3
Ethernet is still "broadcast" (CSMA/CD). It's just that now, with switched
ethernet, the broadcast domain is reduced to the switch port and the station.

------
jwr
One network which I have a particular fondness for is Arcnet. It also used
"thick ethernet" (93Ω) cabling, but all stations were connected to a central
hub. It was remarkably resilient.

I used it a lot for gaming (LAN parties), back in the days when Ethernet
(that's thin coax ethernet) cards were still expensive. Arcnet equipment could
be obtained for cheap (or even free), the speeds were enough for gaming (Doom,
Quake, Descent), the DOS drivers were great, and overall it was a great
solution which Just Worked. Most importantly, it didn't have the problem of
one person bringing down the entire network just by disconnecting the cable at
his station, which thin ethernet had.

See [http://en.wikipedia.org/wiki/ARCNET](http://en.wikipedia.org/wiki/ARCNET)
for more details.

~~~
contingencies
Points for mentioning Descent. A decent remake would be excellent... the extra
resolution of its successors somehow failed to maintain the grit of the
original. We used to play over serial cables before we had ethernet.
Incidentally, another favourite at the time was Heretic. For no apparent
reason my system used to work much faster at Heretic than anyone else's,
showing excellent screen refresh rates despite an equivalent or lower CPU
clock. Never quite figured that one out, perhaps the (Oak?) video card, the
motherboard, or the RAM clock speed. Ahh, the days before pervasive
internet... where social networking meant plugging cables.

~~~
j_s
Descent came up 4 months ago on HN:
[https://news.ycombinator.com/item?id=7948262](https://news.ycombinator.com/item?id=7948262)

[http://descentchampions.org/new_player.php](http://descentchampions.org/new_player.php)

------
jjp
Cached link -
[http://webcache.googleusercontent.com/search?q=cache:_rBACik...](http://webcache.googleusercontent.com/search?q=cache:_rBACikqzuQJ:tech.mattmillman.com/projects/10base5/+&cd=1&hl=en&ct=clnk&gl=uk)

------
tinusg
"Error establishing a database connection"

10 Mbit/s doesn't cut it apparantly.

~~~
jacquesm
How do you know his database server is on the other end of a 10 Mbit link?
What if the datbase and the web server are on the same box and the outside
link is doing just fine but his db is simply overloaded?

I don't think you can take it as given that the network is the problem when
you see an 'error establishing a database connection'. I'd start with looking
at the database.

~~~
easytiger
woosh. He was clearly joking.

On another note... this is clearly MySQL. I recall this error from the 1990s

------
teh_klev
Wow, this is a blast from the past, circa 1992-1998. For my sins I used to
maintain a fairly large Thick Ethernet network for a large textile
manufacturing company in the UK (working for a contractor that basically had
very few clues about employee health and safety, hindsight is a wonderful
thing).

A fair chunk of this network ran through their factory up in the factory
roofspace. I used to climb these ridiculously high step ladders to reach up
into the factory roof steelwork to install "vampire taps".

It used to scare the bejesus out of me, mostly due to an aversion to heights,
the other being that the factories produced cotton thread, which during one of
the processes requires the application of a fine mist of wax or light grease,
I don't remember why. But every high up surface was deceivingly lubricated
with a fine layer of wax or grease as a result of being kinetically atomised
into the air by high speed thread spinners, rollers, spoolers and guides. To
further focus your mind, there was also an opportunity of being impaled on
these massive crane lifted pointy multi-spool holder things should you put a
foot wrong (they were used to lift large bulk spools of rough spun cotton into
even larger dying machines).

Although we had a proper coring tool my biggest fear was of creating a short
between the shield and core and unf*cking that up a 30 ft step ladder in that
environment would have ruined my day (we had to install these things on live
segments, there was no downtime permitted). Fortunately the quality and
accuracy of the tooling was good, the customer used the correct cable (not
some cheap imitation) and my karma and anxiety levels could return to normal
once the transceiver lights flickered into life.

Just thought I'd share my lasting memory and experience of 10BASE5 hands on
work.

------
rcarmo
The most amazing thing here is the USB-to-AUI converter. Wish I could reach
the cached page for that.

~~~
beam
here you go.

[http://tech.mattmillman.com/wp-
content/files/axaui_m1.pdf](http://tech.mattmillman.com/wp-
content/files/axaui_m1.pdf)

[http://webcache.googleusercontent.com/search?q=cache:_rBACik...](http://webcache.googleusercontent.com/search?q=cache:_rBACikqzuQJ:tech.mattmillman.com/projects/10base5/+&cd=1&hl=de&ct=clnk&gl=de&client=firefox-a)

------
nl
He doubts network gaming would have taken off?!

I spent many hours playing Doom and Warcraft 2 on exactly this setup! (Feeling
a bit old now...)

------
lukeh
Wow. I admire this amount of attention to detail (with the custom USB to AUI
interface) for a ”fun” project. Nice work.

------
rwmj
I hope he enjoys going round and working out which ethernet connector has
fallen out, because of those useless "slide locks". I definitely don't miss
thick ethernet.

------
earlz
I actually have a couple of old PCI ethernet cards that have both standard
RJ45 connectors and BNC coax connectors. Does that mean I actually have
something rare?

~~~
kjs3
Not as rare as the handful of PCI ethernet cards I have with a RJ45 and a
_DB9_ connector. 100BASE-CX, ethernet over STP, used for a very brief period
of time so people could reuse their Token Ring wiring plant for Ethernet.

~~~
syncsynchalt
Is it DB9, or AUI? (AUI is 15-pin, and is the card required for this story)

~~~
kjs3
DB9. As I said, it's so customers with a wiring plant based on Token Ring STP
(aka Type 1) could use ethernet at the end points without running new wiring.

------
Zardoz84
I remember when I first mount a network on my house to play with my brother
DooM , with coax Ethernet and with a few ISA network cards that I got for
free...

------
Taniwha
next you have to try the old standard of terminating either or both ends of
your thick ether with thin ether (and then real terminators at the far ends of
that)

(and yes thick ether standardly came with connectors on the end, I still have
a roll somewhere, I have no idea why)

