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ADTRAN and BT Reasearch G.mgfast – 10Gbps Broadband Down Copper Lines

Saturday, August 26th, 2017 (12:01 am) - Score 3,534

Researchers from ADTRAN and BT are working towards conducting the first lab trials of G.mgfast technology in 2019, which could become the successor to today’s hybrid-fibre G.fast technology and one that might conceivably push broadband speeds up to 5-10Gbps over traditional copper lines.

At present Openreach’s deployment of G.fast (ITU G.9700/9701) in the United Kingdom is being marketed with a top speed of 330Mbps (50Mbps upload) and is largely being deployed from existing PCP street cabinets, which makes it very quick to install and cheap to roll-out. The current aim is to reach 10 million premises by 2020 and there’s long been talk of top product speeds hitting 500Mbps by around 2025.

The G.fast standard can harness up to 212MHz of radio spectrum (Openreach’s live network current uses 106MHz) and peak speeds of 2Gbps (aggregate) are theoretically possible via the latest amendments, albeit only over extremely short distances. One recent FTTdp + G.fast trial in the UK delivered 1.66Gbps over 40 metres of copper line, although Openreach would be happy with 300Mbps at 350 metres from a street cabinet (if they can hit it).

Now take a moment and try to forget the fact that Openreach (BT) has yet to officially begin the commercial launch of their 330Mbps G.fast broadband service (even if it already seems to be happening) because the successor to G.fast technology – called G.mgfast (“Multi-Gigabit Fast Access to Subscriber Terminals“) – is already on the way.

At present we still know very little about the new technology, although it works in a similar way to G.fast, is designed for both twisted pair and coax copper lines, can harness a spectrum frequency of up to 848MHz and aims to be a full-duplex solution.

This will mean that most of its benefits vs G.fast can only be fully realised over much shorter copper line distances and that would make it best for use alongside a more expensive and complex Fibre-to-the-distribution-point (FTTdp) network.

gmgfast itu targets

According to ADTRAN, G.mgfast could theoretically offer aggregate data speeds of 10Gbps (Gigabits per second) per cable at 848MHz or 5Gbps at 424MHz. Some of the other companies that are contributing to its development include ASSIA, Broadcom, Huawei, Nokia, Intel and others via ITU-T Study Group 15.

Ronan Kelly, CTO APAC and EMEA at ADTRAN, told ISPreview.co.uk:

“As we have seen over the past 5 years, to quote my colleague Chris Kendall, “Copper may be buried, but it is far from dead”. We have seen vectoring technology breathe new life into VDSL2 deployments, making 100Mbps for the masses a reality.

We have also witnessed vectoring when used in conjunction with newer line protocols like G.fast, deliver initially 800Mbps aggregate bandwidths, and now with amendment 3, thanks to the doubling of the available spectrum, G.fast implementations are delivering aggregate rates in excess of 1.4Gbps per line on loops in the range of 100 metres, making it a perfectly viable solution for Gigabit access in FTT-DP and FTT-B applications over both twisted pair copper networks and coaxial cable assets.

Having realised the superior potential that G.fast technology brings on its own, particularly when decoupled from advancements in vectoring technology, the industry leaders like ADTRAN and many of the prime operator proponents of G.fast, within the ITU have sought to push the envelope even further.

What is proposed within the ITU is a new standard that would see a further doubling and quadrupling of the spectrum used by G.fast, with an ultimate goal of achieving 5 and 10Gbps aggregate rates on coax and Cat6 twisted pair single cables. Currently the focus is to apply this new approach in low crosstalk environments where Vectoring technology is not required. The target operating loop lengths to achieve these rates is currently proposed at up to 100 metres.

The anticipated use case for this new approach is predominantly focused towards backhaul applications for small cells, Wi-Fi infrastructure, and other 106 or 212MHz G.fast DPUs. Due to the current absence of Vectoring capabilities at these very high frequencies, it will be some time before this new standard which has attracted the name of G.fast 3rd Generation within study group 15 of the ITU, or G.mgfast, is available as a mainstream access technology for high cross talk twisted pair environments.”

Should any of this sound familiar then that’s because the approach being taken with G.mgfast appears to have some of its roots in XG.FAST technology, which we’ve already seen being tested (here). Last year Australia’s nbn team achieved a peak aggregate speed of 8Gbps over 30 metres of twisted-pair copper and 5Gbps over 70 metres via up to 500MHz of spectrum. Openreach also conducted a similar test in 2015 (here).

Now here’s the latest simulation of what G.mgfast could do (ADTRAN data) using the two new spectrum profiles vs G.fast’s profiles. Quite a big difference but it’s clearly a short range / sub-100 metre technology and the simulation assumes zero crosstalk (interference), which doesn’t accurately reflect the busy real-world environment of consumer connectivity.

gmgfast adtran performance estimates

However it’s still early days for G.mgfast and as many countries switch to FTTP/H deployments then the hybrid-fibre approach could end up coming under pressure (this may become more an issue once ‘average speeds’ are adopted into ISP advertising), although it’s still too soon to judge. Not to mention the very hypothetical threat from future 5G based wireless broadband networks, although that too has yet to prove itself.

The current prediction is that early research on G.mgfast could be developed towards the first lab trials by 2019 and field trials might then follow during 2020. However ADTRAN clearly states that this is currently more about supplying capacity to existing infrastructure, rather than end-user connections.. at least for now.

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By Mark Jackson
Mark is a professional technology writer, IT consultant and computer engineer from Dorset (England), he also founded ISPreview in 1999 and enjoys analysing the latest telecoms and broadband developments. Find me on Twitter, , Facebook and Linkedin.
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52 Responses
  1. CarlT says:

    ‘What is proposed within the ITU is a new standard that would see a further doubling and quadrupling of the spectrum used by G.fast, with an ultimate goal of achieving 5 and 10Gbps aggregate rates on coax and Cat6 twisted pair single cables.’

    I’m pretty sure what’s in the ground from BT isn’t Cat6 and is rarely a single cable on its own. Crosstalk is an issue.

    This looks a lot like an FTTB technology for right now and seems to be the same G.fast technology with more RF bandwidth.

    Great for coax, reusing existing CATV internal runs. Might have potential for MDUs over twisted pair, could be useful as a very short range fibre substitute but needs fibre and power so close to individual premises and there won’t be the processing capacity to vector it for a while.

    This isn’t a fibre substitute for our network architecture without a lot of work for sure.

    1. Alex Atkin UK says:

      Indeed. If it needed CAT6 then it would be pointless when you can already get 10 Gbit over CAT6 up to 100m using good old ethernet.

    2. Steve Jones says:

      The item mentions low quality twisted pair as well, but I think it’s reasonable to assume that its not for the highest speeds except, maybe, over very short distances like that of a drop wire. That seems to be emphasised by mentioning low cross-talk environments and for some specialist uses. Quite possibly it’s aimed as a copper alternative to using fibre for relatively short links. Maybe also as a building distribution system for FTTB where (especially on new-builds) cat6 makes a lot of sense.

      Copper distribution has a lot of advantages over fibre in that case. It doesn’t require specialist tools (or installation), it’s cheaper and it’s possible to deliver power over copper. Certainly when I was involved in computer centre design copper was much preferred over fibre as the standards moved on first with Gbps and then 10Gbps with fibre increasingly confined to backbones.

      Of course, some will ask what’s new as it’s already possible to deliver 10gbps over cat6 (and up to 100 metres with cat6a), but that’s using relatively unsophisticated modulation. I’m sure if the more sophisticated adaptive modulation and error correcting systems in g.fast can be implemented then multiple Gbps speeds can be taken a lot further over cat6 than is possible with current 10GbaseT implementations.

      Maybe, just maybe, if OR were to install these high speed nodes on the top of poles, then gigabit+ type speeds might be possible using existing drop wires, but the economics of that are finely balanced compared to FTTP and it surely depends on reverse power.

      So, my feeling, is this is initially more about fibre substitution for short links and not about mainstream BB.

    3. MikeW says:

      The ITU slide suggests targets for both “low quality twisted pair” and “quad high quality twisted pair”. The latter sounds like cat6, and the former like telephone cabling.

      The rate-reach graph indicates CAD55, which is a type of drop wire for BT, using 4 pairs of 0.5mm copper; Standard CW1417. As it specifies “no xtalk”, you’d expect this to mean delivery over 1 of the 4 pairs.

      If a G.mgfast node is placed at the DP, then each cable to a house is a low-crosstalk environment (unless bonded), so this isn’t a huge restriction. In the basement of an MDU, it might be more of a problem.

      The same thinking would apply to co-existence with VDSL2.

    4. Steve Jones says:

      It says low cross-talk environment, and that might include cat6. Cat6 can also be shielded (which it typically is for patching cables). After all, 10GbaseT is used in environments like this (and often very densely wired ones in computer centres), and they survive. Of course 10GbaseT has a large amount of headroom – it hardly optimised the achievable throughput, but with an adaptive g.fast type modulation and error recovery system and a larger enough target SNR margin it might cope without all that sophisticated vectoring.

      So I would not rule this out in an MDU.

    5. MikeW says:

      OK. My thinking that there could be problems in MDUs was really with pre-existing telephone cabling. Even then, it would depend on the style of distribution within the building.

  2. MikeW says:

    Interesting to see this touted as backhaul technology for a plain old G.Fast node

    1. Steve Jones says:

      I wonder how far that would get you. 10Gbps ethernet only goes to 100m, and that requires cat6a cabling. However, ethernet modulation and error handling is nothing like as sophisticated as g.fast. Arguably a more sophisticated adaptive modulation system will carry that sort of speed over several times than distance using cat6 cabling. In addition, the specification seems to allow for multiple pairs to be used. You can even deliver a modest amount of power than way. Much the same could be said for coax too. Unlike 10GBaseT it won’t simply stop working at a set distance – it will adapt to what’s possible over any given link.

      Perhaps it would be possible using a new sort of distribution cable in the field with multiple pairs to deliver high speed aggregated output and some power over a usable radius when combined with g.fast FTTdp.

      My suspicion at this stage is it’s all highly exploratory but I’ve no doubt that if something like this can be done cost-effectively some use will be made for it, even if it’s just fibre-substitution for very short links. Fibre requires specialist tools and installation and can’t deliver power. In contrast, cat6 is easy and cheap to install with basic tools and training.

    2. MikeW says:

      Agreed – all highly exploratory. Adtran have simulations running, but even this article suggests lab trials in 2019. A long way to go yet.

      The concept of “copper backhaul” for G.Fast nodes has been around for a while, though. It wouldn’t surprise me if BT were contemplating it for deeper G.Fast nodes in the 2019-2020 timescale.

    3. MrIcaras says:

      @MikeW It’s interesting isn’t it? As if a special cable is needed then it becomes cheaper to use fibre I would have though. But if you can use spare pairs in an existing cable then yes, it’s worth it.

      However I could see that being a huge problem. If any of those copper pairs that are being used for backhaul are cut by an engineer working in the network then that G.Fast node goes down.

  3. Chris P says:

    Huge effort in getting unique pairs back to the aggregation point before the connection gets ip routed.

    When will we see OR using all those pairs going to a pole from a cab for power and data with all the pairs from a consumers home being actively connected and traffic routed via the consumers isp of choice?

    Effectively Fttpd with no reverse power, consumer connections using all available pairs for max aggregate bandwidth, the in hone master socket essentially being a powered l3 switch that can split voice and data? Prob no need to do all homes on a pole in one go either if the active pole kit acted like a mini street cab.

    1. MikeW says:

      I don’t forsee that until the PSTN gets turned off, and the current voice USO gets nullified.

      That seems to be a thing that BT might be thinking about for 2025. If that happens, I suspect it might be something that drifts in area-by-area.

      SOGEA looks like the starting point of that transition.

  4. Kits says:

    Sadly I think BT need to think about this since they refuse to upgrade the copperwires. When I paid BTretail for new line in the engineer refused to change both master socket and drop cable on my home. I have lived her over 30 years it is still the same drop cable so the move over to these new speeds for me would be a failure. If BT wish to continue down the copper route they really need to replace all copper at the start.

    1. CarlT says:

      Why would they replace the copper if it were still working?

      If they replace all the copper it makes the whole exercise pointless. It’s to re-use the existing plant saving the time and expense of FTTP.

    2. 125us says:

      Why would they change it? Copper cables don’t degrade over time.

    3. Joe says:


      The joints degrade/weather, BT could probably check those and replace more than they do. Copper isn’t so much an issue but they really ought to replace the aluminium cables where they find them

    4. MrIcaras says:

      If the dropwire is the modern type and in good working order there’s no benefit in changing it.

    5. PaulM says:

      “…Copper cables don’t degrade over time.”

      Er yes they do and so does all copper. The first signs of copper aging is it will turn green. Hipster types often refer to that as patina in reality its tarnish and oxidation build up. Ironically this helps protects the copper under the green gunk, but over time the build up becomes thicker. The issue that then starts is pitting, in copper pipework that often turns to pinhole leaks, as anyone that has ever had a hard to track down leak will tell you. The recommended lifespan of copper pipes is 50 years though obviously some will last many years longer than that and others will die well before that. But 50 years is a pretty good guide.

      Cables are no different in fact in many cases the situation with old cables will be worse as 50+ years ago copper used in pipes and cables was not 98-100% pure copper as it often is today but it also contained things like lead or iron. In case you did not attend your science lessons as a child iron rusts, when you come across iron that has rusted in a copper cable it typically becomes brittle and will literally crumble in your hand. Before that happens though the outer sheath on a cable will likely become brittle and crumble, making the wire need replacing regardless.

      So now that is out of the way the question on if they should had changed his drop wire boils down to 2 things, 1 condition (which is impossible to tell accurately as it has an outer plastics based sheath). and more importantly its actual age. If his drop wire was more than 20 years old than working fine or not according to BT it should be changed as they believe the lifespan of copper cables to be 20 years…
      section 4.16

      The notion copper does not degrade over time though is pure delusion.

    6. MikeW says:

      In that document, isn’t the time just the period for depreciating an asset, not its service life? So it really represents some kind of average for calculating an average maintenance budget.

      Elsewhere in that document, it describes duct, and indicates “While new assets are depreciated over 25 years, the oldest assets have lives of 60 years.”

      Also worth noting is that the document mentions the access network, but excludes the dropwire.

      You’re also making an assumption about the oxidation of copper. What happens when a proportion of the cables, and the joints, are made with petroleum jelly surrounding the pairs, rather than air?

    7. PaulM says:

      “In that document, isn’t the time just the period for depreciating an asset, not its service life?”

      Nope not unless BT also lie on their accounts… page 72
      3-25 years on there. So how much of it is older which they are also likely lying to the tax man about?

      “You’re also making an assumption about the oxidation of copper. What happens when a proportion of the cables, and the joints, are made with petroleum jelly surrounding the pairs, rather than air?”

      Except petroleum jelly and their crimps are not used at the pole on the drop wire (not mine at least, the pairs in the box on mine are screw terminals, and one of the first things any engineer up the pole down my road does is open it and scrub with his wire brush lol so any jelly in the cable is/was gone years ago) and they most certainly are not used on the 2 connection points to the faceplate.

      Furthermore any petroleum jelly which was actually inside the cables (like on some CAT5/6 outdoor cabling) at either end of those mentioned connections would had gone years ago, just the sun on a pole to house wire would had seen to that.

      Also and more important Petroleum jelly is an old school electrical insulator, NOT a conductor, so from the get go not the best thing for phone lines. It will repel water and that is why it was originally used. The problem is if you apply it to a cable or terminal that is wet or has already begun to oxidise then it basically does nothing as it will be trapping the moisture at the terminal. Ironically that can make things worse and speed up the oxidisation process. Petroleum jelly is not water soluble so while it may keep water getting in it will also trap any water or oxidisation that is already there.

      The better thing to use on cables and crimps nowadays for harsh conditions if we could drag BT out of the 1960s (no chance of that of course) would be something like a copper grease or better yet graphite grease (like what is found in some high end coax and power cables as a protector) which would keep water away but also act as an electrical conductor unlike a telephone line that may have several jelly crimps holding it together.

      If i took my car to a garage for a new battery and they covered the terminals in petroleum jelly rather than something modern and better for the conductivity through the cable and my car starting on cold winter mornings, i personally would not be impressed by the work. Petroleum jelly may well work but i believe in if you pay for work it should be done to the highest standards not just, it will do BT approach.

    8. tonyp says:

      I’m curious about the effect of corrosion of copper surface on the transmission of these very high frequencies. Since Skin Effect means that high frequencies are mainly carried at or near the surface of a wire, corrosion might possibly mean rapid attenuation over time at endpoints. Would that be a problem? How many callouts for Openreach staff in future? Just thinking out ‘loud’.

    9. Steve Jones says:

      Whilst copper exposed to the air, and especially the damp, will corrode, it’s almost completely absent where there the copper is protected by PVC insulation. Issues with damp at connections is well known, but stripping off some fresh wire and a remake will generally sort that out, especially with using water-resistant gels.

      If people doubt this, I suggest looking at the state of the copper under PVC insulation in old cable.

      What really does cause problems is if and when insulation breaks down. Once damp starts getting to the actual copper then corrosion can set in and the presence of the damp itself and failing insulation will caused electrical problems.

      Older PVC is more prone to breakdown over time than newer stuff, but an awful lot depends on local environmental factors. Exposure to light and high temperatures all appear to cause issues with insulation cracking. Modern multi-core telephone cables are constructed in order to resist the ingress of water. They will be full of hydrophobic gels and various other tricks. (Most telco ducting is assumed not to be watertight and it’s the cable, not the ducting that provides the protection).

      From what I read, there is no single rate at which cabling degrades, or a single lifetime. Old cables will be less durable than new.

      In any event, if we all had to replace our home wiring every 25 years, then that would be a huge ongoing expense. I suspect the real lifespan of cables not exposed to the elements is much longer than 25 years, but equally I can imagine that drop-wires and those run over telegraph poles are more vulnerable than more protected cabling.

    10. MikeW says:

      Skin effect (for higher frequencies) means the current is pushed towards the surface of the conductor, but isn’t exclusively on the surface.

      Corrosion of the outer few atoms turns them into something non-conductive. The surface of the conductor is then no longer at the outer edge of the wire, but is a few atoms in.

      The current will still, therefore, push towards the surface. It is just, by definition, a slightly different surface – now the boundary between copper and the oxides. The current continues pretty much undeterred by light patinas.

      As @Steve says, corrosion hardly happens when the copper surface is covered by polyethylene, and even less so when the polyethylene is surrounded by gel rather than air. I do believe that polyethylene is slightly more porus to water than the old lead sheathing; to counter this, either gel is used or the pair bundles are wrapped in a thin layer of aluminium foil.

      The problems come when the sheathing is breached – either deliberately (for joints) or inadvertently (usually by active weathering – ice, wind, UV).

      In the case of joints, we need the current to actually reach the physical edge of the wire, so any corrosion to that edge has a much bigger impact here. It is one reason for the use of jelly-filled crimps.

      Physical deterioration is another matter, and for obvious reasons is worse in drop wires than in underground ducting.

      When faults development in cabling, the likeliest cause is a joint. Next is physical deterioration of a dropwire. But if neither develops a fault, there is no need to replace a cable based purely on age.

    11. MikeW says:

      Thanks. That document confirms the idea that “life” in this context is a calculation for financial depreciation reasons. Tax reasons.

      Obviously you’d expect more modern gel formulations to come into use. I doubt it is still simple petroleum jelly any longer. But it serves the same purpose – within a cable, it is to prevent the ingress of water leaching along a cable and surrounding the polyethylene sheath, seeking weaknesses. And in crimps, to surround the joint with something to keep a corrosive environment at bay.

      I’m pretty sure that using conductive gel in the cable construction would be a terrible idea. Maybe not so bad in crimps, but I can see pros and cons worthy of long-winded experiments there.

      Filling the cables with gel was a technique developed in the sixties (with long-winded experiments), and put into place since then. I’ve heard it said that a lot of D-side cables are of this construction. Perhaps your suggestion of going back to the sixties is unnecessary.

      E-side cables use air pressure to keep water at bay. First mandated in the early sixties. It isn’t as though BT or the GPO have avoided the idea of making cables have as long an in-service life as possible.

      You’re right that not every joint is created in a sealed environment. This seems to afflict the points of flexibility (DP, PCP) more than the sealed underground joints. I guess the saving grace is that, by definition, these places are easy to access to remake joints. And even here, it seems that gel-filled joints are becoming plausible – the new PCP has gel-filled connectors.

      Copper corrodes, most certainly. But things can be done, and are done, to extend the service life as much as possible.

    12. 125us says:


      Copper only degrades in the way you describe when exposed to open air. A copper cable with PVC sheathing will not degrade. The end connections which may be exposed will degrade, but they’re easily remade.

      So my original question – why replace a cable when there’s likely nothing wrong with it? How often do you replace all the electrical cabling and appliances in your home?

    13. PaulM says:

      “Whilst copper exposed to the air, and especially the damp, will corrode, it’s almost completely absent where there the copper is protected by PVC insulation.”

      “If people doubt this, I suggest looking at the state of the copper under PVC insulation in old cable.”

      You can count me as one of the people that doubt that claim.

      PVC (Poly vinyl chloride)degrades with UV light (that would be the sun) and makes it brittle. PVC is a plastic made of around 60% sodium chloride (from industrial grade salt) and around 40% carbon (derived from oil/gas). In case you do not see the issue there its the salt content when combined with UV light. Like a dry salt lake bed the sun makes the plastic dry up, go brittle and crumble over time. It does not take long either, luckily in this country it will tend to last a bit longer outside as we do not have much bright sun most of the year.

      What the sheath on outdoor rated cable should be made of is PE (Polyethylene) or the same stuff which cheap carrier bags are made off which do not naturally decay for many, many years, some say up to 1000 years to come.

      If BT use PVC as you suggest on outdoor cabling im not shocked it has issues.

    14. PaulM says:


      “Obviously you’d expect more modern gel formulations to come into use. I doubt it is still simple petroleum jelly any longer.”

      I would hope at the least it was some type of thermal white grease similar to what you would see inside some electronics (its also quickly the closest stuff i can think of which resembles Petroleum Jelly at quick glance). Compared to the water repelling ability of modern greases, gels and resins Petroleum jelly really is old school.

      “It isn’t as though BT or the GPO have avoided the idea of making cables have as long an in-service life as possible.”

      Not to sound like a conspiracy nut, but that is entirely possible. One factor and the biggest is probably cost. a PE sheath will often cost more than PVC, carbon grease likewise would also cost more than Petroleum Jelly. How much those extra costs would amount to for BTs entire copper cable network i have no idea but pennies here and there soon mount up to pounds.

      I suspect its more a cost V performance choice which is made rather than just performance. In very simple terms (ignoring labour costs etc) If you can have a choice of a single cable that lasts 50 years but it costs £20 or a cable that lasts 25 years but costs £5, you go for the £5 cable as it ends up costing you half the money over 50 years. (again am deliberately keeping that simple to illustrate a point, obviously there would be other costs and factors, but i hope you get the idea).

      “Copper corrodes, most certainly. But things can be done, and are done, to extend the service life as much as possible.”

      I do not disagree with that at all, as mentioned in the initial posting petroleum jelly helps, its just not the best that could be used. Without it though i again agree the lifespan would be much shorter.

    15. PaulM says:

      “Copper only degrades in the way you describe when exposed to open air. A copper cable with PVC sheathing will not degrade.”

      Ill assume you will read follow up posts but in case you do not.

      1. A copper core is exposed to air, how do you think you connect the thing in the first place. Copper is a conductive material, weather one bit is exposed at one end of a cable, or its middle makes no difference, water is conductive, a phone cable carries a charge, conduction burns oxygen. If it were air tight (or rather what you think is air tight) the cable would actually be a vacuum.

      You can test this simple science theory for yourself by making only one end of a copper cable wet, covering it in petroleum jelly, wrapping an air tight cling film around it, grab the bare copper on the non wet end in your bare hands and then shove the wet end in a plug socket, then report back what happens and if you get a nice spark at the end you are holding. That spark will be the conduction of the cable which has ignited oxygen along the cable and made a pretty colour come out the other end.

      2. Ive already explained why PVC is not good outdoors, funny 2 people think PVC is the outdoor choice cable sheath material when even a quick google will show it is not.

      The lengths some will go to to argue they are right when science disagrees is amazing.

    16. Steve Jones says:

      Having looked at cable specs, the main external standard is CW1128 which used polyethylene insulation and polyethylene outer sheath (with an armoured option for direct burial). Internal spec cable is CW1308, and that uses PVC for the insulation and the outer sheath. However, there is also an outdoor spec version (CW1308B) which also uses PVC. However, I suspect that cable is used for wiring in and around premises, and not as part of the main OR network.

      It also confirms that the hydrophobic gel is petroleum jelly (I guess it’s cheap and effective).

      The position holds that as long as the insulation is in good condition, the copper insulators will not corrode. It’s the integrity of the insulation that is the important factor.

      Connections are another matter, but measures can be taken to protect those too. I had some experience of this when the direct-buried line to my house had to be dug up where there was a junction to the underground pair to my property. There had been water ingress into the junction after about 35 years and that had rotted the connection. The connection was remade using some rather elaborate joining, taping along with a very large plastic “sleeve” which was then reburied (they’d have preferred to put in a foot-box, but other services prevented that.

      Given the age of the estate, the underground copper must be at least 40 years old.

      A summary of the cabled specifications here :-


    17. PaulM says:

      “Having looked at cable specs, the main external standard is CW1128 which used polyethylene insulation and polyethylene outer sheath (with an armoured option for direct burial)”

      Thank everything holy for that, when you said it was PVC i thought BT had completely lost the plot.

      “It also confirms that the hydrophobic gel is petroleum jelly (I guess it’s cheap and effective).”

      Yep i think your reasoning in brackets is basically correct, its cheap and does actually help, they really could do better nowadays though. Again i guess its down to cost.

      “The connection was remade using some rather elaborate joining, taping along with a very large plastic “sleeve” which was then reburied (they’d have preferred to put in a foot-box, but other services prevented that.

      Given the age of the estate, the underground copper must be at least 40 years old.”

      I think your cable is pretty common. (story time, skip if you wish) I have lived at my current location for around 35 years and never seen any cable in my street (so similar age to your cable) or surrounding streets replaced until very recently last year when at the bottom of my road one section underground between poles was replaced. This i suspect was only done because literally neigh on every week last year a different household connected to the pair that run to that pole had BT out. At one point they were making 3-4 visits a week. So it was likely replaced more down to being faulty than age.

      When they were doing the work i joked with the contractor about that being a nice “fun” job for them, to which the guy responded, “yeah mate its not in a duct and its so old under a load of other cables, great fun” Apart from the initial breaking the surface on the pavement with machinery they had to use a spade to get to it, the next 5 days were then spent with a man sat there carefully untangling it all bit by bit (about 20 feet a day until the approx 100 feet eyeball measurements) was done. I only wish it was my section that got replaced : -(

      The comedy thing though is they have forgot to remove the last little bit that runs up the pole (i spose you could maybe blame the contractors for that not sure why BT have not just snipped it off). Its now quite funny to watch an engineer not familiar with the street turn up, look up at the pole and scratch his head trying to figure out which box on the pole all the drop wires are going to and when doing a new line install which side of the pole he should place his ladder (each box is on opposite sides of the pole) before climbing up only to then climb back down with a p155sed off expression and another 10 minutes wasted lowering the ladder back down and putting it back up the other side.

      Another weird thing is they have put what i guess is a terminal box on the pole which is only about halfway up for some reason rather than just running the cable all the way to the top, not sure what that is all about. Maybe when the last stages were done the engineer which came forgot his long ladder?

      “A summary of the cabled specifications here :-


      One other potential and new issue i can spot with that stuff is the Clupak paper tape separator. Wonder what happens to that if it gets wet never mind how it will last the amount of years SOME (im not saying all before im lept on) BT cables have been about.

  5. Kits says:

    @MrIcaras That is what I was told then when an engineer came to fix a fault he found out the master socket was the old one that was screws where the copper was corroded he just trimmed some off and put the newer master socket. So if it was like that inside my home what is it like outside?

  6. Bw says:

    I am researching 150 Gbps g.farse with my mate Paul who once met Einstein… This is a blatant attempt to sway policy makers so they can all cover each others backs when they are given the green light on the USO.

    1. CarlT says:

      Your post is pretty blatant. G.fast would do nothing for the USO as you’re quite aware.

    2. Joe says:

      @Carl Except perhaps, if universally rolled out, it might necessitate the end of ADSL/LLU etc which might help maximise the range of existing tech for USO.

    3. PaulM says:

      G.Fast will not even reach the distances ADSL will and is actually slower once you get towards the kilometres rather than metre lengths. So how you think that scrapping ADSL will help the USO nobody knows.

    4. 125us says:


      Turning off ADSL allows the extended range variant of VDSL to be used. Nothing to do with G.Fast.

    5. PaulM says:

      Er NO because VDSL even LR-VDSL does not really improve upon the distance ADSL can go, nor does it help with those a long distance from the cabinet reaching USO speed.

      ADSL2+ infact is capable of more speed than VDSL2 (or FTTC) for distances between around 600 metres and 3500 Metres. So turning that off to try to deliver a USO to everyone is frankly an idiot idea. The LR varient likewise is not better than ADSL2+ from about 700 Metres onward.

      The only advantage of turning off ADSL would be being able to use the frequency range, nothing more.

      Its not going to happen anyway, suddenly turning off and telling millions upon millions of people they will have to take a different product will not go down well. Having no alterantive solution as a backup like an ADSL line would also be maddness. Im not even sure why BT would want it, surely they are happier selling several products than just one.

    6. Lee says:

      VDSL2 provides 20meg at around 1800m.

      Everything before that far exceeds what ADSL2+ can get.

      I’m 570m from the cab and getting 75/18 on a full H128 cabinet.

    7. alan says:

      “VDSL2 provides 20meg at around 1800m.”

      LMAO Keep smoking whatever you are…
      1800 Metres ADSL2+ does higher speed.

      VDSL and VDSL2 at 1800 Metres does 12 Mbps
      ADSL2+ at 1800 Metres does about 19 Mbps

      That is over 50% more than VDSL/2 LMAO

      Do you need help counting again?

    8. MikeW says:

      Lee is wrong about getting 20Mbps at 1800m, but that speed graph is lame. It says it was sourced from Ofcom, but no-one can ever find that Ofcom source.

    9. MikeW says:

      With that speed/distance combination, you’re very likely to be benefiting from thicker copper than normal. It wouldn’t surprise me if you were on a 0.9mm copper pair.

      Some properties will benefit in this way – and it is more likely in rural areas, quite a way from the exchange, where thicker copper was needed to offset the length even for voice.

      So it is possible for premises that are on 1.8km lines to do better than the norm … but the norm is, unfortunately, a lot less than 20Mbps.

    10. alan says:

      “Lee is wrong about getting 20Mbps at 1800m, but that speed graph is lame. It says it was sourced from Ofcom, but no-one can ever find that Ofcom source.”

      Any VDSL Vs ADSL Vs Distance chart will say the same or very similar. There is one from internode floating around that shows basically as near as the same. Given his inaccurate speed Vs distance figures, i doubt his own personal measurement is correct either.

    11. PaulM says:

      Partly my fault here, i explained things clearly enough to the person concerned but failed to make the explanation simple with pretty pictures/charts for them.

      VDSL doing 20Mb at 1800 Metres is a new bit of comedy gold. If that were even close to being true it would mean BT right now would not have to do hardly anything to reach the 10Mb USO as near everyone with FTTC/VDSL is already within 1800 Metres and around 95% of the country have FTTC/VDSL available.

      Unfortunately that speed at that distance is only true in dreams and rather vivid and worrying fantasy though. Also beyond explanation why if it were capable of that he/they would try to argue ADSL needs switching off. Oh well another entertaining conversation.

  7. Darren says:

    I wonder when they have finished faffing about sweating the copper how much cheaper it would of been to fibre up sooner rather than later.

    This G.* technology is catastrophic for upload performance unless you are one of the lucky 2 properties right next to it.

    There’s always a new bout of marketing to distract us from the current iteration of inferior tosh. I don’t believe a word of it anymore.

    1. Bill says:

      I am increasingly agreeing with you. Although I much prefer BT to VM or others, they are receiving too much importance (and state aid) relative to their overall contribution.

      The government needs to start a genuine alternative to BT/OR and channel funds towards it instead.

  8. adslmax Real says:

    What the point of carry on with copper? For heaven’s sake it 21st century now. Move on and get a fibre optic instead.

    1. Steve Jones says:

      Cost and speed of installation, pure and simple.

    2. 125us says:

      £1,000 per house to deliver a service that people won’t pay any more for than the copper broadband they have today.

      Try convincing a bank to lend you money for a rollout on that basis.

    3. PaulM says:

      Would BT need a bank to loan them the money then?

    4. 125uS says:

      I think they probably would, yes, PaulM.

      Any profits made by a business belong to the shareholders. In most cases shareholders are happy to approve reinvestments that makes money, but then we’re back to the same problem; £1,000 a house to deliver a service that people won’t pay any more for than they do today.

      A shareholder, investor, or bank manager might look at that situation and decide that their money is better invested in a post office savings account or put under the mattress.

    5. PaulM says:

      Err you do know that BT in the last year or so have spent…
      12.5 Billion acquiring EE
      Approaching 10 Billion on the current rollout
      3.8 Billion on sport (since 2012, 1.2 billion total for rights alone in the last year)

      I think you will find if you multiply your £1000 per home by the 24(ish) Million homes in the country you will find that comes out to about the same (IE 24 Billion). Even though its been debunked already it would not have cost that amount.

      So using your argument they could had done FTTH to all and had the money or at least the finance to do so.

      Instead, they decided to waste money on VDSL to whore the copper a bit more and enter a weewee match with Sky over sports rights. How does that equate to needing a loan or pleasing a potential investor?

    6. 125uS says:

      The sport thing was a survival issue wasn’t it?

      If Sky had all the sport and BT had none, anyone who wants sport will buy it from Sky, including broadband. Give that those customers are prepared to spend quite a lot each month they seem like customers you wouldn’t give up without a fight.

      I have no idea of the real figures, but the case must have been made that investing in a mobile company would generate a better return than full nationwide FTTH. I pay £40 or so for broadband and about the same for mobile. If the company that sells me broadband bought my mobile provider, their income from me doubles. If they spend the same and upgrade my broadband to fibre and I pay no more for it, their income from me remains the same. Multiply that by however many customers EE has and I can see why the business case to buy a mobile company is stronger than a network rollout.

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