When a phone cable is cut or stolen why is it that the reconnection does not not give everyone their correct number straight away?
I ask this because after this happened in our area on 8th Jan many many people appear to have phones back with the wrong number and many numbers are not correct even now
Both of my numbers were wrongly connected
A pensioner was on local radio saying that she had been reconnected to the local pharmacy number and had lots of calls yesterday
I don't know why it happens, but after my parents were cut off for a week or so due to a major cable being damaged which cut off hundreds of people, lots of people including my parents were connected back to the wrong lines. BT did correct individual cases as a matter of some urgency when reported to them, but seemed not to bother checking all the lines themselves. Fortunately, whosever line my parents got also had a BT wholesale ADSL connection so their ADSL worked even when on the wrong line.
I could imagine it might lead to quite a billing nightmare to correct, or perhaps they don't bother unless someone complains.
Sub contractor with the wrong information thats prolly well out of date as various techs have changed "line pairs" around over time and haven't updated what they've done or the wrong info has come from India...
What is supposed to happen is that what wire goes where is documented HOWEVER it can go badly wrong if a bit of cable has been used and pairs swapped to get rid of faults, and the documentation not kept up.
If the bit that is stolen is a single unbroken length then it should just be a pair 1 to pair 1, 2 to 2, etc rejoin at each end.
But if there is a, or multiple, joint box(es) removed as well then all bets are off as regards the above working. The pair used for a given number will be moved about within the cables to cure faults. No record is kept of which pair is which number for every cable joint along a particular route.
The older the cable, the more faults there have been and the more joints removed, the less chance of the simple pair to pair reconnection working correctly there is.
Dialling 17070 may help in these circs (you may need to release number if it is permanently withheld): it will identity which number it thinks you are ringing from.
Depends where the repair is made. If its simply a matter of inserting a section into a chopped out cable the wires do follow a colour code but with say a 120 wire cable (or more) the colours are repeated and paired with other colours or have tracer stripes which leads to confusion. In the good old days of PO Telephones (all together now - Ahhh!) linesmen and cable jointers were extremely highly trained and given time to make a decent job whereas you can bet nowadays there is heavy financial pressure to finish quickly and probably the work is done by contractors who really dont care.
I imagine it has to do with how well the records have been kept up to date. As I have mentioned, a local industrial estate has been cut off by cable thefts four times so far. Nobody has reported any problems with the reconnections on any occasion.
When I had a new line run to an office recently, the records showed that there was a spare pair available, but, on testing it, the engineer found it was in use and a new undergound cable had to be run to the building to give me a line.
The industrial estate was quite generously supplied with lines to each unit when it was built, so I suspect there have not been many changes. The office building has a high turnover of tenants and the engineer told me there are frequent changes to the telephones.
Almost always because the new cable has been jointed "correctly", whereas the previous one had a number of swapped pairs over the years to correct faults (a pair went faulty so a new pair is swapped over at two ends, one end of which has now been replaced). The details of these pair changes were lost over the years (I've heard there was A Great Losing a few years back, during some IT changeover).
If you've ever seen the rats nest that is an MDF (main distribution frame) in the exchange basement, you'll be amazed that anything is ever corrected right ever again.
It shouldn't do with the modern colour code scheme up to 600 pairs in a cable. The base code goes up to 26 pairs maximum. In large cables bundles of 25 pairs are bound together with a coded binder of which there are 24 codes. Hence the maximum pair count of 600.
Provided you seperate the the cable carefully maintaining the 25 pair bundles and working through each one there is no reason for crossed pairs.
Some time in the 70s we moved from one village to a neighbouring one and took our phone number with us. I asked the engineer who was fitting an extension in the new house how they did it. "Very untidily" was his answer - and having subsequently seen how it's done - he was right.
When the Stock Exchange moved from the old market floor in 1970, the traditional system of waiters and illuminated number boards used to contact members was replaced by a new paging system from Modern Telephones.
Firms had 'paging pads' (keypads) in their offices, connected to the paging system on BT private circuits. The pads were pretty crude devices which, I think, were simple row/column matrices with no encoding, so the number of pairs required depended on the number of buttons! To keep down time to a minimum, every pad had a spare pair so that, in the event of a faulty pair, the fault could be quickly fixed without waiting for BT to clear the fault.
Unfortunately, telephone pairs in the City of London were in very short supply and demand for them kept continually increasing so, every time a BT engineer found a pair with nothing on it, signal wise, it was his lucky day!
Consequently, when faults started appearing on the paging circuits, Modern Telephones discovered someone having a 'phone converstation on their 'spare' pair when they tried to use it!
Cable is often stolen by the simple method of running over a roadside box to get at the wires, undoing one end with an angle grinder and then tying the loose end to the back of a vehicle and driving off. This leads to massive damage as far end connection boxes are dragged our and rips out or damages cables not being stolen as well as those being removed.
The resulting job of joining several hundred (or thousand) bits of cable from a number of wrecked junctions is far from simple and not really the sort of damage the cable documentation was meant to overcome.
Compared to the 100+ core cable I once had to terminate, that had about two or three coloured cores and 100+ white with no other markings whatsoever then the BT colour codes and the bundling makes it a doddle (as long as you aren't colour blind or pissed)
Sounds like the old telephone cable colours. But again provided you are careful when opening up the cable they are still in bundles and the pairs twisted together. One trick when fiddling with any of these multipair cables is to tightly twist the end of each pair when seperating a bundle, not so important with the new colour code but with solid colour plus plain white essential.
Just a slight correction Dave, along with a bit of general info for anyone who's interested :-)
The largest size of cable is 4,800 pair and is usually terminated on the MDF (Main Distribution Frame) in the exchange. This cable usually only goes as far as the exchange jointing chamber where it's jointed to smaller cables (and when I say smaller, they could be up to 2,400 pair) to start their journey through the streets. These are the E-Side (Exchange side) cables that feed the cabinets and there are compressors in the exchanges pumping air into them to a pressure of 9psi.
This is done for two reasons: (a) fault/damage location. In theory at least, once a cable is pressurised there should be no air flow. If there is a flow of air, it means that something is wrong somewhere and pressure transducers along the cable route give an indication of where the damage or problem has ocurred, and (b) air coming out will (hopefully) stop water getting in. Because E-side cables and their joints are big, pressurised and dry, you don't disturb them unless there is a major fault and that's why engineers always change pairs between the MDF and the cab rather than find the actual fault. Some of the E-side cables here in Preston have been in situ since
1953 IIRC and are still as good as the day they were installed.
Cabinets usually take 1,000 E-side pairs (I've never seen any bigger ones and I don't think there are any but I could be wrong) but it's very unusual, and I'd say unlikely, that they would be fed by a single 1,000 pair cable - more likely to be two 500's or two 400's and a 200, or whatever.
It's also very, very unlikely that E-side pair 1 would go to D-side (Distribution side) pair 1. Cabinets are cross-connection points where pairs are cross-connected with street layout in mind and you may well find, say, E258 jumpered to D75 or whatever. D-side cables and their joints aren't pressurised but they are filled with petroleum jelly (that's the cables, not the joints :-)) to keep water and moisture out.
I can't remember the largest D-side cable size but it's very common to have
200 pair cables leaving a cabinet and I'm sure I recall working on a few 600 pair cables in my time. As they leave the cab, they branch off through the streets and eventually you may get a 20 pair cable going to a block at the top of a pole, and finally a dropwire provides your house with the single pair of wires that is your telephone line.
To the OP - there are many, many joints between the MDF and your house and a myriad of reasons why the engineers may have got it wrong but most likely is a combination of bad records and contractors who don't give a toss :-)
Generally speaking, if you have a valid login for an ISP, then that will work on any adsl line that is routed to them - even if its not your one. So if you get connected to the wrong line, its pot luck as to if it has broadband at all, and if so, who its connected to.
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