back to article Cunningly camouflaged cable routed around WAN-sized hole in project budget

Welcome once again, dear reader, to On Call, The Register’s weekly reader-contributed tales of tortuous tech support traumas and triumphs. This week, meet a reader we’ll Regomize as "Leif" who, back in the day, was given quite a challenge: a vendor's European office expanded into an adjacent office building, but the move would …

  1. Phil O'Sophical Silver badge

    So they just implemented a Spanning Tree protocol?

    1. I Am Spartacus
      Thumb Up

      Spanning Tree

      Oh, well played sir, very well played.

    2. Jeroen Braamhaar

      Sir: this icon is for you, bloody brilliant!

    3. David Robinson 1

      But how did they ensure no-one gained root access?

      1. FIA Silver badge

        Sometimes you just have to bough down and leaf that to the security experts.

    4. 42656e4d203239 Silver badge

      You, sir, should not be getting your coat. There are too many pints left un-drunk on ytour table; here is another one for the road.

    5. Roger Kynaston Silver badge

      spanning tree!

      Shirly there were wome banyan vines involved as well.

      Apologies for the blatant bandwagon jumping.

    6. jake Silver badge

      Radia's spinning.

      Have a beer.

      1. Anonymous Coward
        Anonymous Coward

        Re: Radia's spinning.

        > Radia's spinning.

        Not dead yet, surely?

        1. jake Silver badge

          Re: Radia's spinning.

          Nah. She's young yet. About my age.

    7. wolfetone Silver badge

      Comment of the year as far as I'm concerned.

      Have a pint of whiskey.

    8. Jellied Eel Silver badge

      Caternary cabling does not avoid ground loops. Or cats, pigeons, squirrels..

    9. mobailey

      In other words - just a network joining one branch to another?

    10. Fred Flintstone Gold badge

      Comment Of The Week.

      Might even be Of The Month :)

    11. adam 40 Silver badge

      That is

      acorny joke.

    12. Anonymous Coward
      Anonymous Coward


      They were lucky the two building electrical grounds were basically at the same potential. The reason you are supposed to link networks between buildings with fiber, WiFi, RF or laser links is it does not take much in the way of grid glitches or bad weather to cause a damaging surge along that intra-building ethernet cable.

      1. the spectacularly refined chap Silver badge

        Re: Lucky

        Generally the first thing an Ethernet signal will hit internally is an isolation transformer. Ground loops are an irrelevance since you have typically at least 1000V isolation.

        Electrical storms on the other hand are more problematic. It doesn't even need to be a direct lightning strike, and even burying the cable is no guarantee.

    13. zuckzuckgo Silver badge

      Root access?

      But how do you secure root access? A fence?

  2. I Am Spartacus
    Thumb Up

    Spanning Tree

    Well played Sir, very well played.

  3. El Al

    I did once experience the reverse scenario - a wireless ethernet bridge between two buildings, which had degraded into unusability. Only after travelling to the site to investigate did it become clear that where there had once been a small tree, a larger one had just come into leaf :-)

    1. DailyLlama

      We had a similar one: Wireless Ethernet between buildings that got interrupted every Tuesday morning. When the car dealership across the road took delivery of new vehicles, and the transporter parked in the middle of the road to unload.

      1. GlenP Silver badge

        Think I've mentioned before the friend's microwave internet link that went down twice a day for periods, but not at exactly the same time and nor every day.

        She was on the South Coast and the link crossed a bay, every time it was a particularly high tide it would fail for a short while. realigning the link slightly cured the problem.

        1. Jamie Jones Silver badge

          Not the same, but it reminds me of something that happened at home a while back.

          I'd generally leave the computers on over night, and would also tend to have one or two ssh connections to other boxes open.

          One day I came in, the ssh connections had disconnected. No worries, jusr relogin and re-run "screen".

          This happened again the next day... and the day after, so I tool a closer look. Weirdly, each time it happened around 6.55am . My internet link was stable, it was just the link from my 'desktop" (at the time, a customised android-tv box, with windowing, ssh xterms etc. connected behind the tv, used with a wireless keyboard from my sofa!) to my wifi that was getting interrupted.

          The box remained up, it was just the wifi.

          About a week later, I happened to be logged in at that time of day, and it happened again. I'd not even realised the time, but when my link stopped working and I looked at the clock, I realised it was happening again.

          I went into settings.... The wifi had disconnected, and reconnected to "national express coach" - a web visit took me to the front page toutihg "free wifi access for all passengers".

          A National Express coach used to stop over the road, and leave at 7.00 am every day. They had acquired said free wifi access, and for some reason, buried in a submenu, my box had a setting set that read along the lines of "opportunistically connect to non-passworded wifi.

          So, it was connecting to the coach. Once the coach left, it would reconnect to my house wifi.

          A strange and very insecure setting to have - I guess it was originally designed for phones to jump on any free wifi instead of using up cell-data, but why the hell it interfered with a stronger and already established secure wifi connection is anyones guess!

          1. Anonymous Coward
            Anonymous Coward

            ""opportunistically connect to non-passworded wifi."

            So, it was running Android, right ? This thing is always connecting to anything opportunistically, no matter what priority you'd like !

            1. Jamie Jones Silver badge

              Yep.... There is (or at least, there was in this case) an option to disable it, but it was buried deep in some sub menu, and it was enabled by default with no clue on the wifi config page that it was actually a thing!

        2. The Oncoming Scorn Silver badge

          Almost The Same 1970's Style

          Old lady in a remote cottage on the UK coast, complaining her new colour TV lost colour twice a day, various visits by the engineers to fix it without success.

          One day while the TV Engineer was up to his arms in the TV guts, she made the comment about wondering if the tide washed the signal out, engineer has laugh.... then a Eureka moment & checks the aerial.

          Installer had aligned the aerial while the tide was out & the signal bounced off the wet sand, as the tide came in only enough of the signal was present to provide a monochrome picture, realigning the aerial to a inshore transmitter resoloved the issue.

          Icon - Getting me Sou'Wester.

          1. Martin-73 Silver badge

            Re: Almost The Same 1970's Style

            On the Rowridge transmitter was she? Still get multipath due to tides even with DVB-T, if the aerial isn't aligned right. Fortunately at least at Rowridge DVB is transmitted with mixed polarization so aligning the aerial vertically can help

        3. M.V. Lipvig Silver badge

          This was something I was concerned about with my own microwave internet, which crosses a lake to reach the other side, but my main concern was temperature inversions. The dew point that creates fog also acts as a mirror to microwave and will deflect signal for a short time, until the temp wave moves beyond the range of the antenna. The solution is dual antennas with one mounted about 7 field manuals over the other, so as the temp inversion moves it only reflects one antenna at a time. Had a helluva time convincing a customer who had a T1 over microwave to an island on why his circuit was dropping twice a about 10 minutes at a time in the spring and fall, but he finally accepted it, or had a dual antenna set installed.

      2. Flightmode

        We had a backup radio link between two nearby sites, with dish antennas on the roof of both buildings. After a couple of years, the link started acting flaky, but only during early morning through early afternoon, evenings, nights and most weekends were fine. Since it was the backup link we all basically thought that "I guess someone will have to look at that at some point". Eventually the link went hard down and didn't come back up, so after a couple of days someone started troubleshooting and eventually ventured up on the roof to see if something was up with the antenna - damage, birds nesting, cables chewed through by god-knows-what or something - only to came back down after a few minutes.

        "Hey guys, you know that construction site across the street? They've put a hotel in our line-of-sight."

        1. Anonymous Coward
          Anonymous Coward

          The call closure narrative for a place I used to work “Asked the farmer to move his Combine Harvester”. He had parked it in a different place and it was interfering with a line-of-sight link.

        2. Giles C Silver badge

          I put a radio link in between two sites of a company I was contracting for. In the documentation for the project was a note in about 2-3 years (just about now) you need to get xxx to trim the tree in their field or the radio signal will drop out.

          Middle of the fens and the one point we can put the radio there is the only tall tree for 100m in the path.

        3. MrBanana Silver badge

          Line of site can be a curse. I used to live in a house that was, literally, actually, no joking, 10m from a TV transmission tower. But it was a local repeater for only 18 broadcast stations, swamping everything else. Took a while to get the correct aerial alignment, TV configuration, and shouting from the roof "can you see it Grandad" to get everything worked out for a solid connection to Crystal Palace.

          1. Radio Wales

            The optional length of wet string.

            My mother lived close enough to Alexander Palace to throw stones at the transmitter.

            She was unable to receive any signal without receiving the lot! In a colourful blaze of jagged lines and a cacophony of merged soundtracks.

            I found that whoever had installed it had used a hi gain antenna, So just wondering about hyper gain, I pulled the antenna plug out of the TV, and it resolved into a poor but watchable signal.

            Feeling a bit foolish, I put a four-inch length of damp string into the socket, and to my amazement, got a perfect signal.

            I experimented a bit and found that dry string of six inches worked too, without the worry of leaving my mother loose to water her TV daily. Off I went, and later learned she sold her aerial to a friend ten miles further away and kept the loot.

      3. Cian_

        Had much the same issue, except much more frequently - chimney to chimney for two linked doctors surgeries a short walk from each other had good line of sight, except the four times an hour a train went over the bridge over that road.

        They actually lived with it (brief drops on RDP sessions) until better uplink became available on the cable company in that area and a proper site to site VPN went in.

    2. Lazlo Woodbine

      One of our clinets had this problem once

      They were based just by a motorway junction, and needed to know when the junction was clear to release vehicles.

      We mounted a camera across the motorway that had battery backed solar power, with a little wind-turbine for good measure, and a wireless bridge to link it to the office.

      All good when we set it up in Winter.

      All not so good when a tree in front of the office came into leaf in Spring.

  4. lglethal Silver badge

    So can we say this was a migrating cable, that took nest in the trees for the spring, before leaving at the end of summer?

    What is the carrying capacity of a migrating European Swallow Ethernet cable?

    1. Antron Argaiv Silver badge

      10 megabit/s, same as in town

    2. C R Mudgeon Bronze badge

      "What is the carrying capacity of a migrating European Swallow Ethernet cable?"

      Two pigeons. Three is right out.

  5. El blissett

    Now that's what I call Windows networking!

    -- funnily enough I'm pretty sure "Leif"'s vendor used his approach in the rest of their business after the early 90s.

  6. Zinzanescholes

    Did something similar....

    But with an armoured fibre and jackhammer between our office and the basement of a grade 1 listed next door. The noise off Marylebone Road provided cover..... [shame]

  7. Hans Neeson-Bumpsadese Silver badge

    Back in 80's I was working in an office block in the city centre. A fairly senior member of staff moved office from something like 5th floor north-east corner to 2nd floor south-west corner. For some reason the building management couldn't reconfigure the internal phone system/switchboard to shift his telephone extension to the new office, and it was going to take ages / cost a fortune to get an engineer to come and look at it.

    The building manager dispatched me to the nearby British Telecom shop (something of a novelty, as this had just opened as part of the post-privatisation activities) with a wad of cash to buy a load of the longest telephone extension cables I could find.

    I returned with the goods and an insanely long extension was plugged together, using copious amounts of sparky's tape around each connection, and strung around the outside of the building.

    Must have been close to the limit of maximum practical length, but it did the trick.

    1. adam 40 Silver badge

      That sounds just about legal, but back in the day the Post Office had a monopoly on such things, and it was actually illegal to run a wire between two premises.

      1. Doctor Syntax Silver badge

        Back before my time, so it must have been the '60s, a filling station on the outskirts of small toen out in Co Tyrone kept getting done over. It was just nicely positioned for lads who'd been out on the booze to help themselves to a few ciggies & some cash on their way home.

        Solution: alarm sensor in the filling station, bell in the local police house and a few quid to the local GPO linesman to run a length of twin core between them.

        The way i heard it, at one point there were 3 lads doing time in Crumlin Rd., all nabbed separately.

        1. david 12 Silver badge

          few ciggies & some cash

          Classic drug-related crime. In nicotine withdrawal and no money for cigarettes === service station done over for "carton of Marlboro and all the cash in the drawer"

      2. david 12 Silver badge

        llegal to run a wire between two premises.

        Not allowed to cross a road, but were allowed to connect two adjoining lots. Which is why you used a wireless or optical connection, or, in our case, bought from the local council, the lanes entirely surrounded by our university buildings, so that we could run a wire from the computer centre to the other buildings

      3. Jellied Eel Silver badge

        That sounds just about legal, but back in the day the Post Office had a monopoly on such things, and it was actually illegal to run a wire between two premises.

        It can still be. In the UK, it's covered by the Communications Act(s) that specify who can do what. For individual premises, they're covered by a 'self-provision licence' clause that means you can install stuff like switches, cabling, PBXs etc. If that goes off-premise, then it can require a licence, especially if it crosses public property or services are provided to the public. It's mostly to prevent interference to the public networks and Ofcom can jump on anyone who does that.

      4. Martin-73 Silver badge

        Was in the early days post privatization too, to prevent the newly deregulated PABX market from allowing neighbours to share a line...

  8. jake Silver badge

    Over the years ...

    ... I can't count the number of lasers I've used to make connections between buildings. Across cities, occasionally ... and across San Francisco Bay a handful of times.

    That's modulating the beams, not cutting holes ...

    1. Jellied Eel Silver badge

      Re: Over the years ...

      Across cities, occasionally ... and across San Francisco Bay a handful of times.

      Yep, been there, done that. Will it work? Maybe, sometimes. Keep an eye on the weather and fog. For a while I was getting a lot of requests to do jobs like this for the High Freaks (High Frequency Traders) who figured they could shave fractions of a millisecond off fibre routes by using LoS laser or radio links. Including going x-channel from UK to France. Never mind the techinical or wayleave challenges, it's "techincally feasible", so quote me happy!

      Those usually ended up going in the No-Bid bin.

      1. MrBanana Silver badge

        Re: Over the years ...

        I've been on a high pressure trading floor, I've seen the multiple screens, the state of the art CPUs these guys demand, the very latest software, must have microsecond network latency. I've also seen them sat in a chair for 10 minutes getting their shoes polished.

        1. M.V. Lipvig Silver badge

          Re: Over the years ...

          The last company I worked for maintained such a system between Chicago and New York City. It's some customized bodge with no error checking and no telemetry between the spans, each regen node just boosts the signal to the next one. It's been a while since I worked there but I think latency was around 10ms on that span while any other span had latency of about 30ms between Chicago and New York. That span was also laid out almost as though they ran a string from Chicago to New York City, pulled it tight and dropped a regen along it every 30 miles. It was a real pain to work, and there's only one old geezer at an unrelated company that performs any sort of vendor support. He probably gets about 50 grand per phone call off it. Nice work if you can get it. I'm glad I no longer deal with it

    2. Boris the Cockroach Silver badge

      Re: Over the years ...

      How many times were you warned not to cross the beams ?

    3. John Brown (no body) Silver badge

      Re: Over the years ...

      "and across San Francisco Bay a handful of times."

      A place famous for frequent and dense foggy conditions? Well, done if it worked :-)

  9. Spanners Silver badge


    A previous employer had a customer whose network would come to a shuddering stop whenever the weather froze - especially the first one of winter!

    I also remember being told how I should string ethernet cables outdoors in case they got hit by lightning. That never happened but I do remember one that ended up running through a beehive! The cable was there first but nobody thought to tell the bees that they couldn't live there...

    1. GrumpenKraut

      Re: Weather?

      > would come to a shuddering stop whenever the weather froze...

      Because the cold makes the cable shrink and the bends around corner get to sharp, bad with coax. Seen that a one place: -12 degrees or lower simply meant "no network today".

      About lightning hitting outdoors cable, seen it once and it was spectacular. All computers in one building toast, network cards had scattered those little electronicy parts, motherboards and RAM were fried as well. Some computers in the other building somehow survived, no idea how. All in all pretty expensive.

      1. Jellied Eel Silver badge

        Re: Weather?

        Because the cold makes the cable shrink and the bends around corner get to sharp, bad with coax. Seen that a one place: -12 degrees or lower simply meant "no network today".

        Oh yes! Somewhere on the Interwebz there is a great paper on this, but can't find it at the moment. It describes temperature induced flexing. Issue is pretty much all cables are made from materials that have different expansion/contraction rates. So cores, cladding, stress/structural components etc. So as the cable assemblies and joints warm and cool, the different characteristics can end up bending components. That can damage joints and connectors, compress dielectric insulation on co-ax, change the bend radius on fibre causing internal reflection.. And over time, just knacker the cable due to repeated flexing, pulling insulation or protection away etc etc.

        Outdoor cables are usually designed to cope with this, but part of the coping mechanism is to run the cable properly and allow for expansion/contraction.. Clipping it neat and tight with no expansion loops will probably fail, or start to fail after a few seasons. Also read some incident reports from solar installations where this hasn't been done properly. This is bad if it allows pretty high DC current to start arcing and setting stuff on fire.

        1. GrumpenKraut

          Re: Weather?

          > Clipping it neat and tight with no expansion loops...

          That's *exactly* what they did. I looked at the cable going round the corner and was surprised it didn't just snap. Bending radius was below specs even when it was warm.

        2. An_Old_Dog Silver badge

          Bad Installation Practices ...

          See "STAPLES?! Fark, no!" at

        3. Martin-73 Silver badge

          Re: Weather?

          Yes, the fact you can buy steel wire armoured cat 6 worries me... how many data techs will inadvertently provide a metallic path between buildings ... especially bad if they actually bother to gland the cable into something metal

    2. Diogenes8080

      Re: Weather?

      Hot sun is a problem if you need to put a laser link on a steel-frame building. The steel expands as it warms up, which can gently twist the the laser off target. Some sensors don't even work if they are facing a low sun, so the problem only occurs in the early morning or late evening.

      1. RichardBarrell

        Re: Weather?

        I wonder could you put the laser on some kind of very slow precise motorised mount so it could re-aim itself?

        1. Jellied Eel Silver badge

          Re: Weather?

          I wonder could you put the laser on some kind of very slow precise motorised mount so it could re-aim itself?

          Yep, but they tend to get very expensive. Depends how far you're trying to shoot the beam and the dispersion. The endpoints are generally fixed and stable, so generally don't need that much correction. Then again, I was chatting with a manufacturer at a trade show about this. So they gave an example of shooting a link between two tower blocks in NY. Challenge there was the amount both buildings swayed in the wind, and at different rates that meant they had to develop a mount with better tracking. They showed me a video of a test shot they'd done using a visible laser and the spot was moving about 50'..

        2. M.V. Lipvig Silver badge

          Re: Weather?

          You can do quite a bit of aiming. In the 1990s a company called Astarte had an optical cross connect machine that would allow you to make optical connections by aiming the fibers at a pair of mirrors. It was really quite clever. The box had fibers coming into both sides, and were aimed at a pair of mirrors. The fibers were servo controlled and the mirrors had servos that woul allow the mirror to be distorted. Light would come into the box on a fiber, bounce off the mirrors and out another fiber, and the servos all worked together to aim the light inside the box. I actually found a story about it from back then.


      2. dubious

        Re: Weather?

        We had a laser link that worked fine for months, then started dropping out for an hour each day as the setting sun had moved round to where it was swamping the receiver.

        Tried extending the hood and making comedy goggle type things out of pvc tube, but in the end we replaced it with a microwave link.

      3. Anonymous Coward
        Anonymous Coward

        Re: Weather?

        Only had one laser link - around 200m.

        As it had SNMP, and I had some monitoring stuff already going on (Nagios/Cacti/RRD) I collected stats from the two ends. Yes, there was a definite daily variation in received signal strength which was stronger in sunny weather.

    3. Anonymous Coward
      Anonymous Coward

      Re: Weather?

      >but I do remember one that ended up running through a beehive!

      Ah, so that's how you set up a honeypot network...

  10. Kevin Gurney

    About 15 years ago I worked in support at a large theme park situated just outside a very very posh small village.

    One day nothing could connect outside the park - especially an issue when using a third party ticketing provider and credit card processing.

    Finally came online mid afternoon and the reason the telecoms engineers gave was that somebody in his multimillion pound house had decided to dig himself a swimming pool and his hired mini digger had hit something repeatedly......that'd be an armoured cable running under his garden then.

  11. Antron Argaiv Silver badge

    At least he used Ethernet, instead of extending the Token Ring network :-)

    ISTR issues, relating to differing Earth conductor potentials between older buildings and the negative effect that had on comms equipment connected between those buildings. Common mode rejection only goes so far, and many RS-232 drivers were replaced when the terminals were in one building and the computer was in the other. Were I in that situation I might have used a fiber bridge rather than hardwiring. I recall at least one instance where someone got a nasty surprise of the voltage variety when grabbing an Ethernet cable (they were supposed to be earthed (grounded) at one end only) due to ground voltage differential

    1. GlenP Silver badge

      Opto-isolators were common enough back when I started. In my first role, in the mid-eighties on a large government site, we had a switch room full of them. They had, at least, by then got all the buildings wired up although comms speeds at the outer edges of the place could be iffy, a short while before I arrived the distant offices were still connecting via 300/300 modems (and some users still had hand card punches on their desks!)

    2. Jellied Eel Silver badge

      I recall at least one instance where someone got a nasty surprise of the voltage variety when grabbing an Ethernet cable (they were supposed to be earthed (grounded) at one end only) due to ground voltage differential

      Yup. Good'ol thickwire Ethernet was supposed to be grounded. Then if running between buildings, grounded both ends. Just ignore the potential problems of creating ground loops, or induction created by having a long antenna. If you're lucky, it just blows the interfaces. If you're not, it fries the engineers. Seen a few fun situations where I've had to diagnose intermittent faults for clients near London's underground lines. Large building, close to tube lines, long cables running parallel to the tracks. Could stick a meter on the cable and watch the traction current ramp up and down as trains went by.

      So yep, when doing that sort of thing, always use fibre! There can also be risks just going between phases on kit, which is when you tend to find out just how good the electrical installation and earthing was. Interfaces generally have some protection built in, ie opto-isolators, but not always enough to prevent the kit taking an unwanted smoke break.

      1. Anonymous Coward
        Anonymous Coward

        Ah, ground loops. Nothing to teach you better about the importance of a single ground point than building a pirate radio studio pretty much under the transmission mast.

        Let's just say that 400W over 8 dipole antennas* is quite able to give you a hint that you screwed up.

        The joy of a thoroughly misspent youth :).

        *With proper high pass filters. Your life as a pirate radio is measured in hours if you don't ensure you keep harmonics out of air traffic frequences, and deservedly so.

        1. Manolo


          Spurious emissions...

          I used to have them, but now I'm too old for that.

          1. Anonymous Coward
            Anonymous Coward

            Re: Harmonics

            As far as I can tell, they merely migrate to other places :)

    3. Anonymous Coward
      Anonymous Coward

      Yup, already came across that problem when I was using ARCnet (I was young and clueless in those days, but it worked). When the company bought the building next door as well, it quickly became apparent that 'just connecting' was a tad more involved due to the potential difference risks. At the time, optical isolator prices were eye watering.

      Nowadays you just add a device with a fiber capability on either side, run a fiber of the right capability and hook it up. It's not even rare, and even 10Gb/s links no longer cost the earth.

      1. Dvon of Edzore

        Datapoint (maker of ARCnet) had an accessory optical link to get around needing to pay telco to run a wire across a street or paperwork for government-licensed radio links. It was plain optical with big lenses to avoid cost of compliance with laser safety regs at the time. Ended up looking like cartoonish huge binoculars but it worked well enough outside monsoon season.

    4. Peter Gathercole Silver badge

      Forget between buildings. The meal hall of my uni. college had different phases on the sockets of each side of the room, and probably an earth fault as well.

      One of my friends was getting shocks while setting up a PA and lighting system for an event (it may actually have been the same event that had a partial stage collapse during the setup - not good when the performers were John Otway and Wild Willy Barrett when they were younger and Really Free), so stuck a meter between the earth's of each side, and was astounded to see +100V AC measured. Between the earths!

      I think he also measured the potential between the live on each side, and saw a difference there as well, but I can't remember what it was.

      1. Jou (Mxyzptlk) Silver badge

        Try that in Germany with our three phase default for buildings. I measured up to 400 Volts AC recently.

      2. Anonymous Coward
        Anonymous Coward

        was astounded to see +100V AC measured. Between the earths!

        Even 2-3v can be enough to cause problems if you hook a co-ax which has maybe 0.01 ohm resistance along the outer screen. 200A melts an Ethernet cable pretty quickly!

      3. DS999 Silver badge

        Probably served by different electrical panels in turn served by different transformers/service entrances that had their own separate ground rod. You'd be surprised at the potential difference between two unconnected ground rods that aren't that far apart.

        That's why if you need to ground something entering a building somewhere other than where the main service entrance and grounding rod is, you are supposed to drive a new ground rod and connect it to the other ground rod with #6 copper. And why you may want an Ufer ground if you are building anything big enough to use steel beams.

        1. jake Silver badge

          "And why you may want an Ufer ground if you are building anything with a concrete foundation."


          1. DS999 Silver badge

            Almost all single family homes in the US are built with a concrete foundation, but hardly any would be built with an Ufer ground. It has to be steel framed for that to even be possible, which rules out almost all of them right off the bat since most are framed with 2x4, 2x6, or maybe SIPs for green building.

            But I agree, if you can build with an Ufer ground you should. The building the bar/restaurant I used to own had an Ufer ground, having a true ground that could be accessed (well "accessed" once I cut a hole in the drywall and soldered a ground terminal onto the exposed beam) in the audio closet was a big help in killing transient hum issues that reared their head at inopportune times.

            1. jake Silver badge

              "Almost all single family homes in the US are built with a concrete foundation,"

              Steel reinforced concrete. Note the steel, it's important in this conversation.

              "but hardly any would be built with an Ufer ground."

              All an Ufer Ground is is an electrode embedded in concrete. A common-or-garden concrete foundation with rebar in it can easily qualify, as long as the rebar is tied together tightly enough. Welding is suggested, but tighter than normal tie wire that is doubled up (an X at each joint) works nicely. Simply leave one end of rebar exposed after the concrete is placed, and there's your ground connection. There is nothing magical about it. It's the pH of the concrete, combined with increasing free ions in the soil (sometimes called "soil doping") that make such a ground effective. Larger rebar doesn't necessarily make for a better ground, but it does make for better transient protection.

              "It has to be steel framed for that to even be possible"

              Absolutely untrue. This place is stick-built and has an Ufer ground. The big concrete pad outside the main tractor barn is an Ufer ground, and it doesn't have any framing at all on top of it.

              1. Jellied Eel Silver badge

                All an Ufer Ground is is an electrode embedded in concrete. A common-or-garden concrete foundation with rebar in it can easily qualify, as long as the rebar is tied together tightly enough. Welding is suggested, but tighter than normal tie wire that is doubled up (an X at each joint) works nicely. Simply leave one end of rebar exposed after the concrete is placed, and there's your ground connection. There is nothing magical about it. It's the pH of the concrete, combined with increasing free ions in the soil (sometimes called "soil doping") that make such a ground effective. Larger rebar doesn't necessarily make for a better ground, but it does make for better transient protection.

                Ooh.. Filled my quota for learning something new today! I hadn't heard of this before, although I've seen it. I guess it's one of those things that has to be designed and managed in at the outset. Otherwise you may find plastic-coated rebar, fibreglass or the wrong kind of ties messing things up. I'm also thinking differences in corrosion, or maybe even concrete batches could lead to varying resistances and potential differences across the structure. I'm guessing those might result in potential interference rather than hazards. I've seen some interesting civil engineering vids where rebar's been used for apps like measuring movement by using it as a strain gauge.

        2. PRR Bronze badge

          > if you need to ground something entering a building somewhere other than where the main service entrance and grounding rod is, you are supposed to drive a new ground rod and......

          You need to buy another spool of cable so your run CAN come in at the same spot the power and phone/TV come in at. Bringing a cable around the side and then hoping it will nicely dump back to the main entrance is like wishing on unicorns.

          I've cleaned up two houses by scrupulously following the One Entrance religion. One house was burning up a modem or answering machine, or both, every summer. Overhead phone and underground power. Even lost the lightning/cross protector block. And they had run new buried phone when they ran the new power, but never hooked up. Got a tech who agreed the phones were better buried, moved the links, no more trouble. OTOH this house had hum in phone and humbars in cable TV. Everything came to the same pole but not bonded to each other. Measured 2V-3V between grounds depending on loads. Scrabbled in the dirt and got a wire clamp around all four ground conductors, TV was clean and phone was better.

      4. Richard 12 Silver badge

        The no-load voltage tells you more about your meter than the supply.

        Some induced voltage is expected, so a very high-impedance meter will often show apparently scary voltages.

        However, if there's no energy behind it then a tiny load drops it to basically zero as only microamps flow.

        On the other hand, PA systems are often deathtraps, as a lot of fools disconnect the protective Earth "to stop it humming".

        Which I suppose it does, when the singer touches the microphone with their lips and dies onstage.

        1. Great Southern Land

          And let's not forget the home-made power boards some of these bands used. Plenty of potential for disaster there.

      5. Robert Carnegie Silver badge

        Different phases in one room is a no-no, isn't it? A no no never.

    5. usbac

      I ran into some kind of weird ground loop (I think) problem at my house. I had gigabit ethernet ran out to a shed at the back of the property. The run was about 225 feet, all in buried conduit. About every two to three weeks, it would take out the port on the switch (sometimes both ends, but usually just one end). This started getting very annoying, since these were rack mountable managed switches.

      I started by installing a 10 foot ground rod next to the shed, and wiring it to ground the electrical in the shed. It helped. Now I could go a few months between losing ports. Still very annoying. In the end, since I had conduit in the ground, I used the copper ethernet cable to pull a new fiber cable. It's been solid as a rock since.

      Never quite understood what the real cause was. Ethernet is transformer coupled, so ground loops should not be a problem.

      1. jake Silver badge

        Was the ethernet shielding grounded at both ends?

        1. usbac

          It was plain old Cat-5e. Not shielded.

      2. Richard 12 Silver badge

        Was it STP?

        I see a lot of sites running shielded twisted pair out of the equipotential zone and having occasional nasty issues.

        Driving a local Earth rod won't solve it. The problem is that Earth is different at each end, because the actual ground is a rather poor conductor.

        The trouble is that shielded cable becomes the path of least resistance between the two earth rods. Generally far worse when it's been dry for a while, of course.

        The best solution is fibre, of course, but failing that you need a competent electrician to expand the equipotential zone by running chunky copper around.

        1. Jellied Eel Silver badge

          Re: Was it STP?

          The best solution is fibre, of course, but failing that you need a competent electrician to expand the equipotential zone by running chunky copper around.

          This. I know enough to know it can cause problems with cabling and sensitive equipment. Plus having been told stories about people being electrocuted after touching ground and discovering the hard way that it was energised due to bad wiring, or a fault. Having come across problems in the past, I'm glad I was taught to always test the ground before working on any copper cabling, mains or data.

          1. Potty Professor

            Re: Was it STP?

            Soon after we were married, we moved into an 1840s built cottage. My wife noticed that she felt a tingling sensation when she put her hand into the water in the hand basin at the same time as touching the cold tap. I thought that there might be an earth fault in the plumbing, but no, the tap was solidly grounded. The voltage was coming up the lead waste pipe and making the plughole, and therefor the water, live. I cut out the lead wastepipe and replaced it with a plastic one, which cured the symptoms, but not the problem. This was traced to a PVC Flat Twin and Earth that fed the shed, where it ran up the wall and bent to run along the catenary wire, it had cracked and water had entered, so there was a current path through the damp brickwork and into the house via that lead pipe. Permanent solution was to replace FT&E with SWA and make the turn into a big pigtail loop.

            1. Andrew Findlay

              Re: Was it STP?

              This is why current UK wiring regulations require equipotential bonding of all metallic services at the point that they enter the building. In a domestic situation that usually means a continuous 10mm^2 copper cable from the main earth terminal to bonding clamps on each pipe etc. The main earth terminal is provided by the Distribution Network Operator, and in most UK houses is either connected to the steel armour of the supply cable or directly to the neutral conductor. As noted above, the actual ground is not a very good conductor so earth spikes tend to be regarded as inferior, though there is now a move to install them as well to provide backup.

              Services in this context include drain pipes, gas mains, water pipes, SWA ethernet, and the frames of steel buildings - basically anything that could bring in a potential difference from somewhere outside the building.

              1. Martin-73 Silver badge

                Re: Was it STP?

                Including the often neglected (and not listed on the BS7671 model forms) REDUNDANT supplies.... if they're still in the ground and still entering the property (the usual culprit is an abandoned steel gas pipe ) it NEEDS bonding

      3. Jou (Mxyzptlk) Silver badge

        > Ethernet is transformer coupled, so ground loops should not be a problem.

        The problem is that your equipment is still of different ground. If there is a change it will wack onto the coupling as well. And with a distance of about 70 meters you have enough signal loss and induction from electrical fields. It may have worked with shielded cable, but with the shield unconnected on both sides or connected with a 100k resistor instead of direct metal. But it would still have been a long cable buried in the ground - changing to fibre would have been the end anyway on the long run, those tricks would have only delayed it.

    6. Roland6 Silver badge

      >” I recall at least one instance where someone got a nasty surprise of the voltage variety when grabbing an Ethernet cable”

      Worst case with yellow peril is 3KV; however, to achieve this you need to max out the number of MAUs and get them all to start transmitting at the same time…

      This was our testers favourite test, they would get the courier who delivered the MAU to wait 5 minutes in reception, whilst they conducted the test and returned a still smoking and hot MAU to the courier to return to sender, there were several manufacturers who spent months failing this test…

  12. Michael Strorm Silver badge

    'A reader we’ll Regomize as "Leif"'

    I see what you did there. ;-)

    1. The commentard formerly known as Mister_C

      Re: 'A reader we’ll Regomize as "Leif"'

      Thanks for the tip, I hadn't twigged.

    2. Spamfast
      Thumb Down

      Re: 'A reader we’ll Regomize as "Leif"'

      Except that the Scandinavian name 'Leif' is pronounced like the English word 'life' not like 'leaf'.

      My step-son is called Leif and hated it when he and his mother moved to England and even his school teachers wouldn't bother getting it right even after repeated correction.

      Her name, by the way is 'Dagmar' which is okay because she's half German and that's how it's pronounced there with a hard G. However if she'd preferred the Danish pronunciation - which is closer to 'Dowmar' (my apologies to Danish-speakers for the over-simplification) - she'd have had a lot of repeating herself to do!

      1. Anonymous Coward
        Anonymous Coward

        Re: 'A reader we’ll Regomize as "Leif"'

        All the Leifs I've known have pronounced it to rhyme with the English name "Ralph". Assuming you pronounce Ralph to rhyme with Leif, that is.

      2. Michael Strorm Silver badge

        Re: 'A reader we’ll Regomize as "Leif"'

        Ironically, I looked it up to find the pronunciation before I posted that comment, realised it wasn't exactly "leaf" but assumed it was near enough that this was still the intended joke.

        I shall now make like a tree and... get out of here.

    3. Adrian Harvey

      Re: 'A reader we’ll Regomize as "Leif"'

      I presume he worked for Ericsson?

      Or at least used their equipment?

  13. Giles C Silver badge

    I had the opposite problem to Lief we had two buildings that needed to be connected and we put a line of sight radio link between them bolted to the walls on each building.

    On one building there was a lot of ivy growing up the wall (I did not do the installation myself but it contracted out), one day the connection just dropped. Walked over as the buildings were only about 200m apart to check the cabling, inside the building it was good so I poked my head out the nearest window to the antenna, and found the cable neatly cut in half.

    The building owners had sent someone round to trim the ivy with a hedge trimmer.

    We had the cable replaced with an armoured version.

    1. Anonymous Coward
      Anonymous Coward

      Something similar...

      My phone line was noisy but ADSL was fine. BT discovered that the line was fed from a box next door... the front of their house was covered in ivy... ivy had strangled the cable and crushed the insulation

      (ADSL worked because it can work over the proverbial piece of wet string if you are close enough to the exchange)

    2. JimC

      The IT risks of gardeners...

      Been there. Somehow failed to put "the Gardeners" on my list of potential service risks...

      1. Martin-73 Silver badge

        Re: The IT risks of gardeners...

        Have seen it with armoured power cables, metal bladed brush cutters can do a number on 'em. picked one up to examine the damage when it exploded in my face. It hadn't occurred to me that the damage wouldn't have blown the supply fuse. Oops!

  14. phy445

    I Was Made for Dancin...

    At the risk of revealing how ancient I am, this story prompted me to find out whatever happened to Leif Garret? His picture on his wikipedia page indicates that the gods have not smiled upon him...

  15. Will Godfrey Silver badge

    In days gone past

    In the 405line analog TV days, a small farm in Wales lost all TV every summer, until the the next farm along changed hands, and the new owner was quite happy to have the copse 'pruned' - at the other guys expense.

    1. tiggity Silver badge

      Re: In days gone past

      405 line TV - another feel old reference!

  16. Chewi

    I was a student at Durham Uni in 2001, living in halls at one of the colleges. My friend lived upstairs in a block that cornered onto mine. We wanted to share files and play games, but this was in the days before wireless was common, and only the newer halls had been wired up to the network. What to do? Naturally, we decided to have him swing a long ethernet cable out of his window for me to catch. We wanted to be discreet about it to avoid getting into trouble, but that didn't quite go to plan. Aiming and catching the cable was a bit harder than we anticipated. Our rooms looked down over the big common room window, and within a couple of minutes, we had attracted a crowd of onlookers who were enthusiastically cheering us on. "Oooooooh.... awwwww!" After several attempts, we finally managed it and got a big "Hurrah!" Fortunately, no one batted an eyelid after that.

    Beer icon because we probably had a few after that!

    1. Anonymous Coward
      Anonymous Coward

      Students <> "few"


    2. Tom 38

      Van Mildert? I had the dorm room in the Tees block that had the central hub of that network, as well as the interconnect cable between Tees and Middleton (plus the crimp tool and 300m of CAT-5).

      1. Chewi

        Nope, Collingwood. Barnard block.

        1. adam 40 Silver badge

          Downvoted because I was at Bede

        2. Arbuthnot the Magnificent

          Collingwood alumnus here, virtual pint on me!

    3. Potty Professor

      Gutter connection

      When my eldest daughter was at Uni in Bradford, she lived in a "Student House". There were more students in the house next door but one, so in order that they share the cost of a network connection, they ran a coax cable up the wall of one house, along the shared gutter, and down the wall of the other house. This was done with the full knowledge and permission of the owners of the house in between, and the system worked for the whole four years my daughter was in that house, and still is for all we know.

      1. Version 1.0 Silver badge

        Re: Gutter connection

        Maybe in about 30 years your daughter will be posting the details on El Reg and get all the upvotes that everyone is doing today! Your post is a good example of how students can learn a lot of things that they are not "taught" everyday.

  17. LordZot

    Are we sure it wouldn't be best considered to be a trunk line?

  18. aerogems Silver badge

    Kinda surprised squirrels or other forms of local fauna didn't end up chewing through the cable or thinking it was a handy way to get from tree to tree without having to go all the way down to the ground like a sucker.

    Once did a spot of consultancy work for a small outfit that lived in an area where squirrels routinely were flash fried on power transformers, so they needed a UPS to keep their systems running long enough to shut them down gracefully while the power company removed the squirrel BBQ and restored functionality. Somewhat ironically, it was for a mental health firm, so many jokes were made about suicidal squirrels looking to end it all.

    1. I could be a dog really

      At a previous employer we had an animal park as a customer - run by someone who could reasonably be described as the customer from hell,refused to spend a penny more than he could get away with, tried to make it our fault when his DIY network failed, which was quite often.

      They has a washing line network (it wasn't even exterior grade Cat5e) from the office to the entrance shack. Then one day the call came in to say the network had gone down (literally) as the residents had decided the cable might be tasty. After that, the customer from hell relented and put a bit of wire-armoured cable in.

  19. dadbot5000

    This is why the vikings took over Europe.

  20. JavaJester

    I am the Lorax

    I am the Lorax. I speak for the trees, for the trees have no tongues. I am asking you sir at the top of my lungs. Oh, please do not run Ethernet cable through another one.

  21. DS999 Silver badge

    I knew of a company

    That had similar issues but the buildings weren't so close together, but they were able to get someone to install a wifi (or similar, not sure if it was true wifi) link between buildings with a couple satellite dish like things pointed at each other.

    That functioned well enough for the 6-9 month lead time they had to wait before their telco was able to get all the necessary permits with the city to dig up streets, access conduits and whatever for a permanent and supported WAN link.

    1. M.V. Lipvig Silver badge

      Re: I knew of a company

      That would have been microwave link.

    2. pirxhh

      Re: I knew of a company

      Yep, did that with WiFi cards and antennas built fom Pringles cans.

      At home, I made a deal with my neighbours' son: He got Internet (drilled a hole for a Cat5 through his and my wall) in exchange for mowing my (tiny) lawn.

  22. J. Cook Silver badge

    If it's stupid and it works, It's still stupid and you are just lucky...

    Heh. when I was working for [ISP] back in 2000, we were consolidating the various dialup POPs in the state I was in to a centralized location; my task was to remove the old dial up equipment from the sites. One of the sites consisted of two suites in a small office complex that was a square with a lawn 'courtyard' in the middle Of course, the two suites were on opposite sides of this. So what the installer did was to run an ethernet cable around the roof of the complex between the two suites, which apparently worked just fine. (there were.... probably about 50-60 analog phone lines between the two sites, with a T-1 uplink to the rest of [ISP]'s infrastructure. I think.)

    My boss was made that I didn't climb up on the roof and bring the ethernet cable back along with the rest of the equipment- apparently, he wanted to see how well it had faired over the 5-6 years that it had been up there...

  23. d2

    string -beats -cables

    A pal, aka, GOG (GrumpyOldGit ) opined that his lot had A1 results using

    Tin Can Walkie-talkies

  24. chivo243 Silver badge

    I see what you did!

    His name was Lief, and he strung the cables through the tree! Once again, nice work with the regomiser!

    Yes, late to the show, I've been traveling for going on a week...

    1. Paul Hovnanian Silver badge

      Re: I see what you did!

      "His name was Lief"

      Was the company he worked for Ericsson, by any chance?

  25. PRR Bronze badge

    Not camouflaged, just nailed to walkways.......

    Two theaters and one box office in three buildings. Connected by covered walkways. Boss wanted a ticketing system at the three locations. Ethernet was still new. Our boss thought it used telephone cable, and had saved his old phone wires. I did my diligence and got good CheaperNet coax. Spent a week on a ladder drilling wiremounts in brick and in Aluminium cladding. Most of it was under metal roofing but one run ran exposed on the face of a building, on ano-black cladding. That one I did pick a black coax to lessen the visual sin. Coax Tees at each end for terminators. Ran 300 feet each way from the middle, so right at the nominal limits. But there were only four machines into one server, so collisions were not heavy.

    It all worked far better than I deserved. In a decade, aside from undertrained staff leaving terminators off, and one lighting hit, no hard failures.

    1. Robert Carnegie Silver badge

      Re: Not camouflaged, just nailed to walkways.......

      Tell us about the... did you mean lighting hit or lightning hit? There have been several of the latter in these comments.

  26. Hazmoid

    many years ago on a multi million dollar project

    The company I worked for managed the accommodation on a work barge that would be towed out to sea when there were cyclones threatening. The original internet was provided by a Satellite dish on the top of a hill, about 300 meters away from the barge tie up point. An ethernet link was run down the hill and connected across the gangplank , and was regularly damaged because of the 10m tides! So when I first started we suggested that we use a wireless link between the top of the hill and the barge. Attaching the receiver on the barge was easy, the receiver at the top of the hill was more of an issue as the site managers were very strict about H&S. If I did it the correct way it would have taken 3 weeks and copious paper work to get permission to climb the ladder on the outside of a container and attach the aerial with an ethernet cable and some cable ties. So one morning, one of the managers drove me to the top of the hill with the required equipment and looked the other way :) 15 minutes later our wifi link was up and it stayed that way until we decommissioned the barge 3 years later.

  27. Wzrd1

    Well, I've saw uglier

    Some years back, I was the information security officer for a forward deployed military installation. The installation originally being a pre-positioned stock storage facility, which was ginned into depot service for a certain pair of wars.

    While there, our enterprising folks with the Patriot missile battery decided to connect their missile battery command post to the installation network. Not a whisper of a by your leave, just jackass in and hope for the best.

    So, I'm walking from the chapel parking lot, where I stowed my vehicle upon arrival to work and came upon a cat 5 network cable ever so carefully stretched along the ground, with concertina wire protecting it. Yeah, razor wire security and worse, when I followed said offending, unauthorized cable, it was plugged into our classified network.

    I disconnected the cable, changed the combination on the door lock and cut several 1 meter segments from the cable, then kicked the rest of the cable into the wire, then filed a thoroughly irate report as to the major security breach. Their harebrained attempt ended immediately.

    Around two weeks later, they dutifully launched one of their Patriot missiles in the general direction of the airport, thankfully, not locked onto any target. The missile, lacking a target, promptly committed suicide and crashed into the ground - literally in the Minister of Defense's actual back yard.

    Said unit then became the patriotless missile battery for the duration of their stay in country.

    Alas, both stories are entirely true and involved one singular unit.

  28. irrelevant


    I remember one client, early 1990s, in the process of a massive expansion, taking a lease on office on the opposite side of the road from their existing location. And only then asking how to link then together. I gather that it was going to take way to long to do anything official, so they hired a cherry picker and a pile of cones and basically carried out an unauthorised road closure late at night to string some cables across at height. Definitely an arcnet cable, probably telephone too. This was in the very early days of Midland Cellular, before they became Phones4u.

    (a later expansion, into bigger still offices, was a bit too far to do the same, so after attempting a microwave link, they rented a kilostream connection instead..)

  29. john wayne
    Big Brother

    Similar, but indoors

    About 20 years ago, Scottish NHS, medium sized hospital, working in IT support. The medical records people needed a single computer in the sub-basement casenote filing room, 2 floors below the rest of civilisation. Proper "official" cabling install quote was choked on by Finance, so i decided to just run a very long patch lead from the closest node cabinet, after hours. It went from the node cabinet behind switchboard, into the suspended ceiling (yes, those horrible tiles, but my do they hide a multitude of sins) , across the switchboard office suspended ceiling, into the main services riser, down two floors, then out of the riser , into the corridor, and along some conveniently placed ceiling mounted cable tray, and into the back corner of the filing room. Then round the wall, and finally stopping at the desk with the newly installed computer. Crimped both ends with RJ45 connectors, and plugged it in, job's a good un. Total cable length was only about 60m from switch to PC, worked perfectly for another 12 years (and 2 replacement/upgraded PCs) until they closed the filing room when they microfiched the older records then destroyed them. Those were the days when we had the freedom to do custom cabling jobs, and run cables up into the roofspace, cover some ground, then drop back down in a room which previously had no networking. Nothing like that goes on nowadays (nothing im going to admit to), and the cabling contractors all make good money retro cabling all the offices which no-one ever thought would need computers or cabling in the 1990's. Icon because as the freedom to JFDI began to erode, the bosses always wanted things done "the right way", even if it cost money.

  30. Anonymous Coward
    Anonymous Coward

    A friend of mine lived across the street and a few houses down from an ISP owned by another friend.

    In a dark and not-so-stormy night, a drum of thinwire Ethernet cable was buried under the road (that was conveniently getting new blacktop) and through a few neighbour's basements.

    This semi-legit internet connection was used to set up what's now one of the bigger national dotcom brands.

  31. Dafyd Colquhoun

    Mega patch cord

    In one job I worked I needed to run VNC to control an industrial PC. It had been built with a "home" version of Windows and so there was no RDP (yes, "industrial" and "Windows" shouldn't in the same sentence). The telecoms people were able to patch up fibre from the control centre to the remote site, and some high power SFPs for the media converters at each end. All up it was a 100km patch cord.

    I know of a power company that lost microwave SCADA every now and again, and it turned out their 'line of sight' was blocked by modern huge cruise ships in the river. Ships were smaller when the link was established.

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