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Welcome again to a special festive On-Call, in which we dredge worthy tales from the On-Call inbox and give them a spin to compensate for the lack of pre-Christmas news. And also because lots of people write in and we should give lots of you a go. Today: stupid, stupid people with stupid explanations for simple things. Let's …

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  1. Olivier2553

    Ethernet fan out

    I think I remember, from the times of 10Mbps, fat, yellow, coaxial cable Ethernet, there was something called a fan out (or multi ports transceiver). So the Internet fan story makes sense.

    For the young readers around here, at that time, Ethernet was a fat (above 1cm diameter) coaxial cable, with markings every 2 meters or so, where one could attach a computer: an electronic piece of equipment was attached to the cable, it had to be at the precise mark, and a cable was run from the transceiver to the computer.

    If several computer had to be connected in close proximity, one had to use a transceiver that had multiple ports to accept multiple computers. This was called a fan out.

    1. goldcd

      Internet Fan Outs

      Are still in use in the world of fibre.

      Should you not feel up to splicing your own cables, you can buy a bundle of optical fibre with a socket on the end, where they all terminate.

      So you do you connect to a single one of these fibres? You put a fan out on the end - one big socket on the cable, and a bunch of sockets on the other end for each of the individual fibres.

      1. swm Bronze badge

        Re: Internet Fan Outs

        The original Xerox ethernet was RG11 foam coax (cable TV coax) and had 75 ohms impedance. Sections were connected together with 50 ohm connectors. It ran at (slightly under) 3 MBits/sec. We never worried where the taps were (they were cable TV taps. I built a TDR to find faults in the cable/transceivers and could see all of the connectors.

        One problem was that the taps were designed for outdoor use and the swaying of the cable would break any oxide buildup but in a building the cables didn't move.

        Tapping these cables wasn't hard with the proper tools.

    2. Norman Nescio Silver badge

      Re: Ethernet fan out

      Vampire taps and DELNIs.

      As a result of a lack of DELNIs, we had a comms cabinet filled with a helix of 10BASE5, with a tap every 2.5 metres. Once in place and working, nobody dared touch it.

      1. dom_f

        Re: Ethernet fan out

        And drilling the cable was scary.... (yes you had to drill a hole in it to add a device)....

        1. Anonymous Coward
          Anonymous Coward

          Re: Ethernet fan out

          "And drilling the cable was scary...."

          IIRC the later "vampire" taps were self-tapping to make the task faster and more accurate.

      2. Chris King Silver badge

        Re: Ethernet fan out

        *boggle*

        With (nine ?) ports on a DELNI, that's a LOT of thick-wire - how did you get all that in the cab, given the bend radius of that stuff ?

        One thing's for certain - I wouldn't want to touch that either, unless I had DELNI's ready to replace it !

      3. Anonymous Coward
        Anonymous Coward

        Re: Ethernet fan out

        !0BASET was easier to handle - but users had a habit of disconnecting a PC by removing the cable in parts - rather than just detaching it with the T-piece. Thus breaking the daisy chain for everyone else.

        The "knowledgeable" user made life really difficult by replacing their PC with a terminating resistor in the T-piece.

        1. Adrian Harvey

          Re: Ethernet fan out

          I think you meant 10Base2, not T. T was for Twisted pair - just like the modern stuff...

          By the way, does anyone else remember AMP taps? A kind of structured 10Base2 where a cable ran to each wall socket from the previous one, and patch cables (to use current lingo) contained 2 coax cables - one up and one back - and the plug that went into the wall socket broke the through connection and ran the signal up and back when inserted. Not cheap, but solved all those little user issues...

          1. DrBobK

            Re: Ethernet fan out

            Yes

          2. Martin an gof Silver badge

            Re: Ethernet fan out

            does anyone else remember AMP taps?

            I presume you mean Safertaps? Interesting that they're still listed at RS :-)

            They went together with a special "Y" cable which avoided the need for a T-piece.

            IIRC the make/break was done with microswitches that were operated by the inserted cables. I wired an entire office with these once, all fed back to a 4-port isolating hub. Bloomin' expensive at the time, but saved a heck of a lot of "the network's down" type problems when users moved their computers or tidied their desks and pulled a wire out.

            M.

          3. Andy Taylor

            Re: Ethernet fan out

            I remember the AMP connectors, we also used cables/sockets made by EAD which look like German phone connectors.

            Be thankful you never had to support a Wang VS system with its dual coaxial cables and multiplexers...

          4. Anonymous Coward
            Anonymous Coward

            Re: Ethernet fan out

            "I think you meant 10Base2, not T."

            You are correct. I thought "10BASE2" - and wrote "10BASET". Possibly a mental glitch as I was thinking forward to the T-piece references.

          5. John Brown (no body) Silver badge

            Re: Ethernet fan out

            "By the way, does anyone else remember AMP taps?"

            Yes. Except those spring connectors could bend themselves and cause a break with temperature changes (maybe cheap sockets were used), especially in an old building with a Victorian style heating system which involved no radiators as we know them today, just 3-4" diameter cast iron pipes at about desk height just below the wall sockets. We eventually told the customer that we'd not be attending any more network cable failures until they did something about it as it was an environmental issue we had no control over, not a wear'n'tear or damage issue. (no, we didn't install it.) As you might expect, everyone "south" of the affected socket would lose network connectivity, and after "fixing" it, required a Netware server reboot to get those users reconnected.

        2. Vic

          Re: Ethernet fan out

          !0BASET was easier to handle - but users had a habit of disconnecting a PC by removing the cable in parts - rather than just detaching it with the T-piece.

          That's 10BASE-2.

          10BASE-T is twisted pair.

          Vic.

      4. Norman Nescio Silver badge

        Re: Ethernet fan out

        For those who don't know what they are missing:

        'Building a 10BASE5 “Thick Ethernet” network': http://tech.mattmillman.com/projects/10base5/

        The 10BASE5 cable minimum bend radius is...108mm

        http://www.belden.com/techdatas/metric/9880.pdf

        1. Hans Neeson-Bumpsadese Silver badge

          Re: Coaxial network cable

          Ah yes...happy memories of "T-piece Trees" constructed by a colleague who wanted to connect as many machnes as possible at a single point on the network

          1. GrumpyOldMan

            Re: Coaxial network cable

            I had a T-piece Tree on my desk as an ornament for years. Hours of pointless fun re-configuring it.

    3. Anonymous Coward
      Anonymous Coward

      Re: Ethernet fan out

      "[...] and a cable was run from the transceiver to the computer."

      Often to find that the wrong end of the drop cable had been fed through the maze of cables under the false floor. ... and a gender changer didn't solve that problem.

    4. Richard 26

      Re: Ethernet fan out

      It's probably ever so slightly late in the day to make this observation but there aren't actually magic spots on the cable where you are allowed to make taps. They are merely there so you don't put them too close together.

      1. oldcoder

        Re: Ethernet fan out

        Actually they were.

        The purpose is to fit the wavelength. You put it elsewhere and your signal strength drops... and you can't connect to other systems on the same cable.

        The marks were two meters apart - and the end of the cable had a ballast resistor to kill reflections that would wipe out the signal.

        Putting things in the wrong place just isolated the computer.

    5. Yugguy

      Re: Ethernet fan out

      Why have you got 7 downvotes? Is this a taboo subject.

      1. Chris King Silver badge
        Pint

        Re: Ethernet fan out

        "Why have you got 7 downvotes? Is this a taboo subject".

        Rough crowd, or too many folks not downing enough of these to forget -->

      2. Martin-73 Silver badge

        Re: Ethernet fan out

        Re Downvotes: probably from people who are still bitter about the non-vampire transceivers, who have experienced trying to solder an N connector (I think it was?) onto both ends of a freshly cut 10base5 cable, CAREFULLY, coz LANs were new and very fussy, in a cramped position under a bench or desk, or behind a row of lockers, or gawd knows where, while users screamed about loss of productivity from all corners.

        No, I'm not one of the downvoters, I was young enuff to be in training back then, and only had to watch, to learn.... and to hand tools, solder, cold wipes (for the solder burns) etc.

    6. Paul IT

      Re: Ethernet fan out

      Not in use but still hanging from the wall in our building - not quite able to reach up to it to pull down.

  2. Anonymous Coward
    Anonymous Coward

    Cable degradation

    I recently had a Talk Talk "engineer" in the comms room looking at our dodgy Ethernet First Mile internet connection (just say no kids; it's crap) and, with a straight face, tell me that the cables needed replaced as the amount of data that had gone through them had worn them out. All them electrons you see sir.

    It was the last thing he said before I escorted him off the premises.

    1. allthecoolshortnamesweretaken Silver badge
      Coat

      Re: Cable degradation

      No, no, that can totally happen when coders use the wrong font and all the 1s have really sharp edges.

      (Mine's the one with the high-end hifi accessories catalogue in the pocket.)

      1. Tikimon Silver badge
        Coat

        Re: Cable degradation

        Don't forget pointed comments from pointy-haired bosses...

    2. GrumpyOldMan

      Re: Cable degradation

      Oohhh - the stories I could tell about Cable and Clueless! Or Cable and Useless and they became known....

    3. Anonymous Coward
      Anonymous Coward

      Re: Cable degradation

      'Too many electrons' are normally obvious from the smell of smoke and the melting cable...

      1. Terry 6 Silver badge

        Re: Cable degradation

        Duh! If there are too many electrons they all bunch up at one end. You'll see the bulge.

    4. Steve Aubrey

      Re: Cable degradation

      I used to tell people about the ones and zeroes on a disk - sometimes if it got bumped, a zero would turn up on its side and start rolling as the disk would spin. If it picked up some ones along the way, it could get too big and cause a head fly-away (opposite of a head crash, and just as terrible).

      Solid State Drives have ruined my little story.

    5. Alister Silver badge

      Re: Cable degradation

      And if there's a break in the cable somewhere, there's always a strong smell of TCP as the packets leak out...

  3. Chris King Silver badge

    Incompetent admins and migration saboteurs

    Last job had 'em both - mostly "senior" academics.

    My predecessor had been sacked 18 months before (I'd have to tell that tale as AC as the circumstances were fairly unique and quite spectacular), and during that time a procession of individuals had helped out running things...

    Including a senior academic who had managed to weasel his way in to privileged access on several systems. Can you say "personal fiefdom", children ?

    This individual came to give me the "Do you know who I am ?" routine when I changed all the superuser passwords and locked him out. He took this to be a declaration of war, and questioned EVERY decision I made from that point, until his boss told him to shut up and let me get on with what they paid me to do.

    He also tried the "migration saboteur" routine on a number of upgrades, at one point even trying to set up a "secure" intranet for senior management on his personal workstation. You guessed it, security by obscurity and no authentication whatsoever.

    HE folks will also be familiar with the concept of the "central compute server" - usually some crusty old VMS or proprietary Unix box that's been around since the early days of the IT service. Even if you can provide better alternatives for everything it offers, people get very fond and possessive of such old systems, and decommissioning can be a nightmare. Especially when the senior profs start pulling rank and send complaints up the management chain. Last one of those took me the best part of a year to kill (the server that is, not the profs), despite the fact that most of the profs who wanted to carry on using it had *laptops* with more compute power at their disposal.

    Admittedly, Pine 1.ancient was still a nicer UI than the Lotus Notes client, but let's be honest, that's not difficult.

    1. TRT Silver badge

      Re: Incompetent admins and migration saboteurs

      Unless IT sneakily announces rolling 24 hour outages on their diverse server real-estate. All the individual old servers, which come back up identical to previous and no-one knows the wiser, except that they are now imaged virtual machines running on a 3PAR. All mission critical servers now running off one single piece of hardware. Imagine what chaos could follow if, say, the one disk failure tolerant 3PAR RAID had two simultaneous failures.

      1. Anonymous Coward
        Anonymous Coward

        Re: Incompetent admins and migration saboteurs

        Today's fuck-up was brought to you by the letters "K", "C" and "L", and the number "2" (for the number of simultaneous failures)?

    2. Paul Crawford Silver badge

      Re: Incompetent admins and migration saboteurs

      Even if you can provide better alternatives for everything it offers, people get very fond and possessive of such old systems, and decommissioning can be a nightmare.

      More often than not, the problem is it is running some old OS/libraries that special code needs, and that is why you get serious resistance to change. If you can offer it on a VM then mostly its a non-problem, but alas few can run up VMs that emulate old VAX hardware/software, etc.

      Yes, I know you should not end up in that position, but academics like to solve something once and move on. At least its not IE6 based...

      1. Orv Silver badge

        Re: Incompetent admins and migration saboteurs

        In academia you also get the problem of having to reproduce, for comparison, results someone got in 1989 with C code written for a SunOS 4 machine that was under their desk. And you have to reproduce them on the same hardware your slick new algorithm runs on.

        That's actually not a hypothetical -- I was once tasked with getting a program that fit exactly that description to run on CentOS 5. Fortunately it didn't use many libraries, but a significant amount of header sleight-of-hand was required. Oh, and compiling in 32-bit because the sizes of all the types were hard-coded.

        Years of this has put me in an odd situation where I can successfully troubleshoot build problems in languages I couldn't write "hello world" in if you put a gun to my head. I know more about the LISP memory model than any sane sysadmin should.

        1. Chris King Silver badge
          Pint

          Re: Incompetent admins and migration saboteurs

          "I know more about the LISP memory model than any sane sysadmin should".

          There isn't enough mind bleach in the world to erase the mental scars that LISP, Prolog and Poplog can inflict. Thank goodness for alcohol !

        2. Vic

          Re: Incompetent admins and migration saboteurs

          In academia you also get the problem of having to reproduce, for comparison, results someone got in 1989 with C code written for a SunOS 4 machine that was under their desk.

          I rather like jobs like that. I have a fair-sized library of obsolete old hardware (including quite a bit of IPC/IPX) :-)

          Vic.

          1. Orv Silver badge

            Re: Incompetent admins and migration saboteurs

            It's a fun challenge! In some ways the really old code is easier, because it's less likely to rely on large libraries. Code that's ten years old or so and relies on an obsolete version of Boost can be a nightmare.

            1. Paul Crawford Silver badge

              Re: @Orv

              "In some ways the really old code is easier, because it's less likely to rely on large libraries"

              Another factor is they often had all the code on CD or tape, etc. Now if you try to create an old-ish machine often you simply can't get the code from that era because it was all on-line and downloaded then and not archived. Or was, and now has been replaced. Because no one needs to maintain old stuff do they, it has to be new, new, new? And more or less incompatible...

    3. ecofeco Silver badge

      Re: Incompetent admins and migration saboteurs

      Pine. God I haven't thought about Pine in ages.

      I kinda miss it.

  4. Andy Livingstone

    SPED???

    Really??

    1. alferdpacker

      Re: SPED???

      Now I really want to know what's wrong with "sped".

    2. Graham Dawson

      @Andy livingstone Re: SPED???

      It is the past tense of speed. Open a real dictionary and read the etymology of the word instead of relying on urban dictionary.

      While you're at it, look up the definition of context.

    3. phuzz Silver badge
      Headmaster

      Re: SPED???

      For example "As I put my foot on the accelerator, the car sped up".

      1. TRT Silver badge

        Re: SPED???

        Or the Toyota version, "I put my foot on the brake and the car sped up."

        1. rbcmp

          Re: SPED???

          Or the correct Toyota version, "I *thought* I put my foot on the brake and the car sped up. Of course it was actually the throttle. My bad."

          "Show me the evidence," you asked? http://blogs.wsj.com/law/2011/02/09/oh-what-a-feeling-study-pins-accleration-blame-on-drivers-not-toyota/

          1. Anonymous Coward
            Anonymous Coward

            Re: SPED???

            "Or the correct Toyota version, "I *thought* I put my foot on the brake and the car sped up. Of course it was actually the throttle. My bad.""

            Yes, you'd think when they add "The harder I pressed on the brake, the faster it went" that the nickel would drop.

            Same thing happened to Audi back in the 90s.

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