Ethernet Cable Categories Explained: A Brief History…

Dry subject . Though this is quite a good potted history from the blog of Fluke Networks…

https://www.flukenetworks.com/blog/cabling-chronicle...

The first version, 10BASE5

Ah, thick Ethernet and vampire taps... happy days (?)

…or how to take down the entire network with one BNC disconnection 🤣

In reply to a post by Pheasant:

…or how to take down the entire network with one BNC disconnection 🤣

You seem to be enjoying this dry subject a little too much, I could always resurrect the 'Fibre dropwire construction' thread if you want 🤣

🤣🤣

In reply to a post by Pheasant:

…or how to take down the entire network with one BNC disconnection 🤣

Don't remind me, had to super glue the terminating resistors on to the end of the T-pieces to stop the sodding children stealing them once they knew what they did....

Apologies for ripping open those (non-self healing...just like 10Base5/2) scars...😆😂

I was an undergrad in computer science, early nineties, when we discovered how to down a lab full of monochrome NCD X terminals. At least it helped me with my EE understanding the 'practical' application of signal reflections in waveguides

Edited by Pheasant (Thu 24-Mar-22 20:45:38)

All these years later some things haven't changed that much.

People (adults) seeing an ethernet patch lead loose on the desk think "oh that should be plugged back into a data point yes?"
Naturally, they will helpfully do this even when the other end is already patched or comes out of the back of the SIP phone (the PC data passthrough).

At least the managed switches can guard against the resulting loop though it can end up with the phone being disconnected too.

During my seagoing career, 1977-2002, I remember on one ship, with my colleague officers, watching the 1997 film Speed 2 where the villain hijacks a cruise ship by tapping into the ship's network. We all howled with laughter, but in 1999 I was onboard the mv APL France, a Korean built 86,692 Gross Tonnage Containership. I was the only British Officer; all other Officers were Dutch and the crew Indonesian. The Dutch system, at least then, was that their Officers were Maritime Officers, skilled in both Deck and Engineering, whereas the British system was to have Deck Officers and Engineer Officers. I originally was a Radio Officer, but post GMDSS and having electronic and electrical qualifications, became a Technical Officer. We were appointed to ships for around ten weeks as trouble shooters for any tasks which had built up. After our ten week stint, another TO would not return for a year.

One Friday afternoon all was quiet with the promise of a quiet weekend, when everything in the ships control room died, no displays of control and monitoring systems, nothing at all except for self contained instrumentation. The common link was the 10Base2 network. There was very little in the way of technical documentation on this particular ship (and for that matter its sister ship the APL Indonesia which I was on the following year). The Chief Engineer remarked that one end of the network was at his office pc, next to his cabin below the bridge; as for the other end of the network.....

I went to his office and since it was all I could do, I used my test meter to check for the engine room end 50 ohm terminator; my meter read high ohms, so looked like the network coax had gone open circuit, but where?

I went back to the ship's control room to hear that an Officer's wife, who was travelling with her husband, has telephoned him to say that she was dusting his desk in their cabin and had inadvertently parted a cable that was on his desk! When the ships were built, the shipyard had looped the network coax through three Officers cabins which they assumed would be occupied by Engineers (ie a conventional manning system), however the ship owners did not go to the expense of fitting these pc's and simply linked the two BNC coax connectors together. I went to their cabin and found that his wife had managed to pull one of the coax cables out of the BNC plug. I remade the connection and the network and instrumentation returned to normal.

A simple fault, a simple fix, but could easily have been much more difficult to locate.

On another ship found that due to a failing fridge in the Chief Engineer's cabin, there were earth currents flowing through the network coax braid. His fridge got unplugged, but not for long.

Cheers!

Thanks Clive. Great story. 👍

Although 10 Base2 was “elegant” in that it required a minimal cable and no central switch or hub to make it work, it was notorious for being easy to break and a nightmare to fault find. Don’t think any more explanation is needed as to why we graduated to star wired twisted pair!

In reply to a post by Pheasant:

At least it helped me with my EE understanding the 'practical' application of signal reflections in waveguides

When I left uni back in the dim and distant I got a job in a government research lab at Aldermaston (yes, the atomic weapons place), so had access to things like fast (for the time) 'scopes, pulse generators etc. So it was easy to set up fairly short (<10 metre) bits of coax etc and watch what happened when you sent sub-nanosecond edges and pulses down them and played with the terminators, couplings, bent/squeezed the cable etc.

Rather like your experience, it put flesh on the bones of the rather dry theoretical lectures on transmission lines and, later on, what TDRs could tell you

In reply to a post by billford:

The first version, 10BASE5

Ah, thick Ethernet and vampire taps... happy days (?)

the first time I used a network at home was coaxial, i had a lodger and needed some way of connecting my computer and her computer to the net the same time, so connected both to a computer in my bedroom with a modem inside using this coaxial network. When we went to ADSL, I just replaced the dial up modem with an Alcatel stingray modem that BT supplied at the time. Sharing dial up was not great

How things have changed, with routers, now wireless can be used, not that i use it for my main computer and anything else I can wire directly I do.
I installed a 10GB/s fibre optic network in a friend's house, super superfast, but what a pain in the neck, i can understand why copper cables have not been replaced.

In reply to a post by zyborg47:

I installed a 10GB/s fibre optic network in a friend's house, super superfast, but what a pain in the neck, i can understand why copper cables have not been replaced.

I should do a little thread on fibre and on how much that has changed and developed in the last 25 years too.

Incredibly more so than copper LAN cabling in many ways. Not just fibre itself, but much like Moores Law the incredible price drop in “actives”

In reply to a post by Pheasant:

I should do a little thread on fibre and on how much that has changed and developed in the last 25 years too.

Incredibly more so than copper LAN cabling in many ways. Not just fibre itself, but much like Moores Law the incredible price drop in “actives”

Even back in the day copper Ethernet was expensive. In 1990 a 10Base2 ISA cards where the thick end of £200 each. The main thing that has changed in fibre is the proliferation of multimode fibre standards, going from OM1 throught to OM5 now. I have long held the view that multimode fibre is something of a mugs game. Sure it's cheaper in the short term but as soon as you want to move to a higher speed you almost inevitably have to replace the cable with a new one to support the higher speed.

In the meantime had you just installed singled mode fibre in the first place you could just replace the optics at either end. The money you saved by cheaping out with multimode has now evaporated.

That said I still use it where the cable runs are short and not permanent (aka I need to get to two racks over and a DAC cable won't reach). Other than that it's single mode every time. The head of our networks at work has finally come to the same conclusion and it's now single mode everywhere unless you have a really good reason otherwise.

The other main change has been the standardization on LC connectors. Well apart from GPON which seems to have standardized on SC simplex. Those FC connectors where a nightmare, and MT-RJ never seems to have taken off and I have never seen them in a deployment anywhere.

The MTO/MTP connectors seem to be gaining a bit of ground now too. Had to use them for some 40Gbps links last year because QSFP+'s that would have taken ordinary LC connectors with duplex cable where on a greater than six months lead time I hate AOC cables, the weight of the SFP/QSFP just makes running them a nightmare, and if you damage the fibre it's game over. Also if a lasers go bad (happens more than you might imagine) then you are replacing the whole cable, which again argh.

In reply to a post by zyborg47:

I installed a 10GB/s fibre optic network in a friend's house, super superfast, but what a pain in the neck

I don't think it's that awkward, having seen some commercial installers bash through splice trays I don't think the time penalty compared to doing twisted pair to a similar standard is massive. But I have yet to see it 'to the desk' in a commercial environment, there are still advantages to Cat6A in that setting.

At a domestic level I pulled a load of pre-term patch cable through my house alongside the Cat6, admittedly I would only recommend it for a self-install where you know the routes and won't damage them in future, but I expect it to last for a long time.

Having some SC/APC on a patch panel beside the altnet entry point raised an impressed eyebrow when their tech came around! The knowledge that there would be an extra connection on the optical path didn't bother them.

In reply to a post by jabuzzard:

In reply to a post by Pheasant:

I should do a little thread on fibre and on how much that has changed and developed in the last 25 years too.

Incredibly more so than copper LAN cabling in many ways. Not just fibre itself, but much like Moores Law the incredible price drop in “actives”

Even back in the day copper Ethernet was expensive. In 1990 a 10Base2 ISA cards where the thick end of £200 each. The main thing that has changed in fibre is the proliferation of multimode fibre standards, going from OM1 throught to OM5 now. I have long held the view that multimode fibre is something of a mugs game. Sure it's cheaper in the short term but as soon as you want to move to a higher speed you almost inevitably have to replace the cable with a new one to support the higher speed.

In the meantime had you just installed singled mode fibre in the first place you could just replace the optics at either end. The money you saved by cheaping out with multimode has now evaporated.

That said I still use it where the cable runs are short and not permanent (aka I need to get to two racks over and a DAC cable won't reach). Other than that it's single mode every time. The head of our networks at work has finally come to the same conclusion and it's now single mode everywhere unless you have a really good reason otherwise.

The other main change has been the standardization on LC connectors. Well apart from GPON which seems to have standardized on SC simplex. Those FC connectors where a nightmare, and MT-RJ never seems to have taken off and I have never seen them in a deployment anywhere.

The MTO/MTP connectors seem to be gaining a bit of ground now too. Had to use them for some 40Gbps links last year because QSFP+'s that would have taken ordinary LC connectors with duplex cable where on a greater than six months lead time I hate AOC cables, the weight of the SFP/QSFP just makes running them a nightmare, and if you damage the fibre it's game over. Also if a lasers go bad (happens more than you might imagine) then you are replacing the whole cable, which again argh.

Token Ring, the closest competition, was comparatively more expensive than Ethernet, let alone FDDI or god forbid ATM. By the end of the decade Ethernet had pretty much wiped the floor with the other competing LAN standards and it became dirt cheap, further cementing its dominance. It became so dominant as we know its reached well past LAN heritage.

re single and multi-mode fibre - it was harder to see, back then at least, how much the cost of actives would drop. Like perhaps 500 fold or more...crazy when you think about it. When I used to design for commercial office clients, we'd always hedge and put single mode and multimode backbone links in a roughly 50/50 split - typically clients would ignore the SM and just use MM for all their inter-switch links.

As you say single-mode fibre hasn't really changed that much - the two actual changes in the fibre itself, that spring to mind are the widespread adoption of zero water peak fibre and I guess bend-insensitive (or should that be bend tolerant) cabling. Just better manufacturing really.

Connectors on the other hand have always been a bit of a lottery as to what was going to succeed or fail long term. When LC came in the late nineties it was quite a revolution everything for the previous decade being mainly ST or SC. MT-RJ was a bit of a flash in the pan pushed hard by Molex, but failed to grab a foothold. Installers didn't really like them much either.

I'll reserve judgement on the more modern high-density connectors...

Just sniffing around the Ethernet Alliance website, whilst getting links for another thread I stumbled across a series of blogs on a series of interviews with the the guys from PARC that basically invented Ethernet in 1973 (the year I was born!)

Interviews: The Voices of Ethernet

YouTube: Retro 10base5 Thicknet and 10base2 Thinnet network