back to article BT sues supplier for £72m over exchange gear that allegedly caused wave of ADSL outages

BT is suing a supplier for £72m after it delivered nearly 100,000 defective landline connection blocks that caused ADSL broadband outages, London's High Court has heard. Legal filings reveal that Tii Technologies is said to have supplied 95,000 faulty jack test (JT) blocks to BT over a period spanning 2006-2016. The one-time …

  1. Phil O'Sophical Silver badge

    denied the steel contacts in the JT blocks were at fault, telling the court: "A break in a contact as described would cause a continuous fault, being a physical or electrical break in connection. Neither would (without external factors for which the Defendant is not responsible) cause intermittent (i.e. irregular or non-continuous) faults."

    Bare steel will rust, and I've have thought that copper wires pushed straight into IDC slots on rusting steel would certainly lead to intermittent contacts, and even "rusty-bolt" diode effects that would play havoc with ADSL.

    1. iron Silver badge

      I've had experience of a street cabinet that was letting in water and had rusty terminal blocks during the ADSL era. It definitely did not cause complete conection loss. What I got was intermittent slow downs, especially when raining, to the extent that at times I was getting 0.5 meg up instead of my usual 8 meg but still getting the standard 1 meg down.

      BTs line tests and my ISP insisted there was nothing wrong and I had to do the "yes I'll pay for the engineer visit if I'm wrong" bit. Fortunately I got a really good BT engineer who fixed it, put me on a different set of terminal blocks that were not rusty and even set the exchange to retrain the line. I never had another issue with that line.

      1. John Brown (no body) Silver badge

        "Fortunately I got a really good BT engineer who fixed it, put me on a different set of terminal blocks that were not rusty and even set the exchange to retrain the line."

        Or he was aware of the internal discussion re a "known fault" and knew how to fix it, one way or the other.

        I've been doing break/fix for years and "known faults" are never communicated to customers until the shit hits the fan. And that can take years while the blame is apportioned and bounced around, re-apportioned and bounced around again and again.

    2. the spectacularly refined chap

      IDC connections generally result in a gas-tight connection due to deformation of materials and the sheer pressure created at the contact surfaces. I wouldn't expect any issues there regardless of materials simply because there's no scope for anything to get in to cause corrosion. Plain steel is far from a novel material is this particular application.

      The article is light on details, to be fair we probably need more details to come out in court. Reading between the lines it sounds as if the issue is not with the IDC connections but the contacts on the opposite side, to disconnect the line and allow a test clip to be attached. BT have one hell of a lot of published specs for all sorts of hardware like this to the point their specs are often used as a shorthand for the electronics industry. For example I'm quite used to referring to CW1308 cable or BT52 relays.

      I can't imagine a spec not being drafted for this component, but an assertion that it doesn't conform to that spec is not a headline claim, indeed there is a quote from the BT chap responsible for the spec clearing the connector.

      Far to little detail to start apportioning blame, but I would at least consider the premise some BT boss has decided "we slipped up in our procurement, let's try to pin this on the supplier so it doesn't come back on us."

      1. elaar

        If that were the case, then why did the supplier immediately offer the shims??

        Plain steel is an awful material to use in this circumstance, which is obvious from the number of BT callouts.

        I'm not sure how much more evidence you actually require here?

        1. SImon Hobson Bronze badge

          Perhaps the supplier had been able to identify the problem and came up with a solution that was quicker, easier, and cheaper to install than replacing all the blocks. it may not have been a fault with the block, it could have been faulty installation - I don't know, there's not enough in the article and I wasn't there.

          But the supplier offering a fix doesn't mean that the supplier is at fault - only that they've identified a way around the problem, whoever caused it.

        2. the spectacularly refined chap

          The spec and the contract perhaps? If BT asked for steel contacts are the suppliers at fault for providing them? Did they? I don't know, I doubt you do either. It doesn't matter to you because you've made your mind up. I am awaiting details.

          What is clear is they have an established relationship. It wouldn't be beyond the realms of possibility the shims were offered simply to keep BT happy, or even to avoid a sueball for what is probably 100x the face value of the contract.

          It also dates back to 2005, or possibly even earlier, when BT asked the supplier to modify an existing design. ADSL was in its infancy back then, essentially experimental roll outs. Was ADSL even mentioned?

          I don't know. Nor, do I suppose, do you. Unlike you I choose to reserve judgement rather than make knee-jerk reactions about things I don't know about.

          1. SImon Hobson Bronze badge

            Having worked with the sort of IDC termination systems commonly used in phone networks, including plenty of 237A disconnect blocks (which is what I imagine this story is about, or something very similar) I would expect them to be steel in order to get the right springiness. Something like copper would not have the right mechanical properties. I would expect the steel to be plated in order to minimise corrosion.

            I could speculate that the problem is the contacts that are closed when a test connector is not inserted. The contact pressure is probably a lot less than that between the wires and the IDC terminations, so it's quite conceivable that corrosion could occur there and create a bad joint - which would disappear when testing the line as inserting a test connector would wipe the surfaces clean. I've come across a number of such test points that have been damaged (I speculate by shoving incorrectly sized objects like screwdrivers into them asa bridging tool), and hence the block needed to be jumpered across to bypass these damaged contacts.

            For the un-initiated (if they are still reading), the 237A disconnect block has 10 circuits, 2 wires (one pair) each - and it's called "disconnect" because inserting a test probe disconnects the circuit. Connections from (e.g.) the exchange equipment would be connected to one side, and the connections to the subscribers' lines would be connected to the other. Normally, internal contacts pass the circuit from one side to the other, but a test probe can be inserted which a) opens the contacts and thus splits the circuit, and b) gives access to the connections of one side. So at the exchange, you could insert the test probe, disconnecting all the wiring from the exchange, and thus test the exchange port. Insert the test probe the other way round, and you disconnect the line from the exchange and can test the wiring downstream.

            There will be multiple points where this is possible. In the exchange itself, the exchange ports are terminated onto banks of them, and there's a 'kin big frame across which jumper wires can be routed to similar banks of connections that feed the multi-pair cables out to the green boxes. Then in the green boxes, the same thing happens on a smaller scale to route from the big multi-pair cables to smaller ones that feed up to the top of poles or to underground joints. And so, if the connector blocks are "defective", there's multiple points where this can cause a problem with services.

    3. jake Silver badge

      Notes from the field.

      Corrosive air can elude the thought processes of the unwary ... In the mid-80s, I was working for a company that built gear to dynamically allocate bandwidth between voice and data.

      Incredibly Big Monster of a company started getting weird bit errors on their global T1 (E1, T3 etc ... ) network. I was assigned to track down the problem after lower level techs couldn't figure it out.

      Going thru' the data, I discovered that once the problem started occurring at any one site, it gradually became worse ... It was never bad enough to actually take down a connection, but network errors ramped up over time.

      Further review showed that the same team of installers had installed the gear at all the sites with the problem.

      I flew out to Boca (the first site reporting the errors) and discovered that they had installed punch-down blocks in a janitor's closet ... directly over a mop bucket full of ammonia water. Seems it was the only wall space that was unused almost universally in such spaces.

      Blocks relocated and corroded kit replaced, no more bit-errors.

  2. Peter2 Silver badge

    BT claims Tii's designers used bare steel contacts which rusted.

    I'm going to go out on a limb and assume that the designers originally specified something which is corrosion resistant but expensive, only for it to be replaced with bare steel on cost grounds by a Pointy Haired Boss to "save money".

    1. Cynic_999

      I cannot conceive that anyone who would even be capable of designing a viable IDC contact block, no matter how incompetant, would have specified untreated steel for anything they knew would be exposed to the open air. Thus I am pretty sure that this was a mistake that occured between the design phase and the manufacturing phase.

      1. Peter2 Silver badge


        The only way I can conceive of this happening is a Pointy Haired Boss changing the spec between the design reaching him and manufacture. (I can just see the thought pattern; If I change the spec on this one part it's half the price, and the one I tested in my office worked just fine...)

        I can't see how else something this absurd could possibly happen.

      2. John Brown (no body) Silver badge

        "Thus I am pretty sure that this was a mistake that occured between the design phase and the manufacturing phase."

        Built to cost in a Chinese factory with no one bothering to check any of the productions runs after the first test samples were produced?

  3. Anonymous Coward
    Anonymous Coward

    Prior to FTTC, I resorted to a large bleed resistor to keep my line reliable. The hint was that speeds would pick up when the handset was off-hook. Classic poor connection issue, never managed to get it fixed.

    1. elaar

      Do you mean a "bleeder resistor"? Theoretically that would have no effect whatsoever on your line?

  4. tip pc Silver badge

    Wet VM outside connector caused havoc

    I Had issues with VM that went on for ~ 6 months. Started in Spring carried on all summer and finally got fixed in Autumn. I had an engineer attend what felt like every other week.

    it was one of those typical years with a wet summer. It'd rain, but be ok ish, service would fail a day or 2 after the rain even if it was dry outside, then get better even if it was currently raining.

    VM continually swapped me to other customers connections in the street cab and couldn't work out the issue.

    the last guy replaced the sodden connector in the box attached to the property and all was sorted. It was a sunny day and he showed me the connector and tapped water out of it.

    getting through the call centre to get an engineer was always a miserable experience, especially when they claimed not to support Mac's, i then lied and said i was on windows, a few times they wanted to remote onto my machine which always required a stern no thanks.

  5. batfink

    so let me get this straight

    So the manufacturers wanted to solve the problem of the rusted contacts by providing "195,000 metal shims"? Made from the same material as the suspect contacts presumably?

    No wonder BT were unimpressed.

  6. vogon00

    "diagnose apparent line faults on BT's network which the latter says were caused by the defective JT blocks."

    Don't see them winning this point. If you send your engineers out to look for line faults, they can 'see' upstream and downstream with their test equipment, which should reveal the 'fault', even if it a JT block or MDF joint at fault.

    Several times in the past when I have persuaded OpenReach to send an engineer, despite the dire warnings of charges if it's MY wiring at fault (Hint - it isn't, I check each time, and 'test' at the demark/NTE with 'my' side disconnected), their TDR gear always shows up an impedance mismatch somewhere outside the property. On one occasion, the distance shown on the TDR to the 'fault' put the fault in the local exchange. Sure enough, turned out to be a badly punched connection on a Krone patch at the switch site...

    The other thing that doesn't help is the records. Last I heard, the E-Side/D-Side records database maintenance had been outsourced overseas (and usually is wrong). Also a family member recently had to guide the OR engineer to a BT 'Manhole' in the hedge that didn't even appear on their copper network diagrams. Apparently, it was on the 'map' a few versions ago, then suddenly disappeared about 10 years ago.

    The OR Engineers were chuffed as they had been looking for a whole load of faults in the village and were able to cure about 90% of them in one go!

    1. Tessier-Ashpool

      I had one hell of an impedance mismatch problem when a storm blew down a massive tree opposite my house, which left broken phone lines trailing across the road. On my mobile to BT support, it was a little amusing to hear her say that they would run a line check.

    2. Intractable Potsherd

      "... didn't even appear on their copper network diagrams."

      During my recently-ended regular visits from OR engineers (I'm on first name terms with some of them now) to sort out recurring line problems, one of them mentioned that about 100m of line from the cabinet to the house went missing from the map a few years ago and has never been put back. Of course, it isn't an obvious missing bit - it stops at another cabinet put in decades after the one were connected to...

  7. Anonymous Coward
    Anonymous Coward

    Pretty sure this is still ongoing. One of the most common notes I see back from openreach (when the engineers can be bothered to provide notes at all) is "caused by damp/corrosion". Unfortunately where it all goes wrong is where some dodgy subcontractor gets the task and just gives the terminal block a quick clean rather than replacing it. The end result being that the faulty returns in six months.

    1. jake Silver badge

      I still connect over dial-up from my property in rural Mendocino county about 20% of the time ... sometimes at speeds as low as 1200 bps (sea fog and aging, cracked, dusty cable plant makes for bad signal/noise ratio) ... And that's barely 200 miles by road from Silly Con Valley!

      Mine's the one with the Telebit Trailblazer in one pocket & floppy with Kermit code in the other ...

  8. Duffaboy

    2006 to 2016

    Did i miss something as i only skimmed the article, did it take BT 10 years to figure out what was causing the fault ?

    1. jake Silver badge

      Re: 2006 to 2016


      Fail is right ... furrfu!

      1. Duffaboy

        Re: 2006 to 2016


    2. Anonymous Coward
      Anonymous Coward

      Re: 2006 to 2016

      No, Not at all. They took the well-worn path of all large organisations and investigated the problem.

      It took three months to figure our what the problem was, then for nine years and nine months the blame ricocheted around the company until they found enough momentum to point a finger at ... someone with money.

  9. Anonymous Coward
    Anonymous Coward

    Trickle down

    I assume if Open Reach win, they will pay some to $ky, who will compensate their customers?

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