Fast broadband in Rural Yorkshire (FAIL)

Discussion in 'Broadband' started by Martin Brown, Mar 24, 2015.

  1. FTTC requires a fibre node to be installed next to the street DP, I think
    it has to be within 200 metres as the cable goes from the street DP to
    the premises.

    However, up to I think 500m from the exchange, possibly 800m in less
    densely populated areas, you may not be serviced by a street DP, but
    rather copper straight to the distribution frame in the exchange.

    If the exchange is more than 200m as the cable runs from your premises,
    then you're too far from the exchange for VDSL from the exchange, and
    there's no street DP to park a fibre / VDSL node cabinet next to to
    supply you from the cabinet.

    If you live close enough to the exchange you can get VDSL, the people
    that can't get it are those who live too far from the exchange for the
    VDSL but not far enough to be served by a street DP which a fibre/VDSL
    cab can be hooked up to.
    Denis McMahon, Mar 25, 2015
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  2. It's not the hardware cost. It's the electricity supply costs based on PSU
    size for the unmetered supply.

    A size X PSU is deemed to draw x KWh per year from the mains, and the
    telephone company is billed for electricity on that basis.

    What they need is a size X/10 PSU to install in cabinets that only supply
    20 (instead of 200) VDSL lines, although it would probably be nearer to
    X/8 as the fibre side power requirement probably doesn't scale, even if
    the VDSLAM side does.
    Denis McMahon, Mar 25, 2015
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  3. Martin Brown

    Martin Brown Guest

    Is it really completely beyond the wit of man to design a smaller PSU?

    Whatever happened to whole systems engineering?
    Martin Brown, Mar 26, 2015
  4. Martin Brown

    Martin Brown Guest

    OK. Thanks for that clarification.

    Would metering FTTRN PSU feeds not be one way out of this bind?
    Martin Brown, Mar 26, 2015
  5. Martin Brown

    Martin Brown Guest

    I am on an exchange only line at 3 miles from the exchange in rural
    North Yorkshire. There is no cabinet at all between me and the exchange.
    There was a roadside non-cabinet until a hedge flailer destroyed it some
    years back and there is now a hole in the ground with the interconnects
    in it and usually out of standing water.

    The closest FTTC enabled cabinet is further from me than the exchange.
    VDSL in rural settings you *have* to be joking!

    ADSL or ADSL Max is the most you can hope for out in the sticks.
    Martin Brown, Mar 26, 2015
  6. VDSL is how FTTC travels the last 200m.
    Denis McMahon, Mar 26, 2015
  7. The PSU's will have been designed to a BT spec that takes into account
    unsupervised operation in street cabinets with varying environmental
    conditions and powering a specified amount of equipment. Whoever supplies
    the cabinets will have designed (or procured) a PSU to the BT spec, and
    they'll ship that with the cabinet.

    Designing a smaller PSU will probably involve various testing processes
    before BT will approve the new PSU, it's going to be a low volume item
    and the design and approvals process is not going to be cheap. It may be
    the case that the cost of procuring smaller PSUs (to reduce the
    electricity bill) is so high due to the high design and approval process
    costs and small anticipated production run (possibly not worth
    programming a line for, so it's all going to be manual production, and
    that means more inspection costs too!) that BT have decided they're
    unwilling to pay that cost.
    Denis McMahon, Mar 26, 2015
  8. Martin Brown

    Phil W Lee Guest

    Rather more than that, except for the very lucky and/or entirely
    I think you may be thinking of the distance over which VDSL2 76/18mbps
    can be supplied at full speed, because I'm 600+ metres from my cabinet
    (as the wet string meanders), and I get 60 down / 14.65 up, with 0.62
    ES/Hr average. ISTR an article giving 1.5km as the distance beyond
    which VDSL gave no speed increase over ADSL, but that might not be
    correct, either due to my memory or subsequent improvements in
    technology. For example that may have been prior to things like INP
    being implemented, or vectoring being trialed, both of which will
    extend the reach even further (but only on VDSL). I do have INP,
    which has improved my speeds by a bit and my error counts by a lot.
    SNRM is up too, so there may be a bit more speed to come as DLM
    settles down.
    Phil W Lee, Mar 26, 2015
  9. Martin Brown

    Mark Guest

    How can I find out if my connection has INP?
    Mark, Mar 27, 2015
  10. Martin Brown

    Phil W Lee Guest

    If you use a router/modem which you can monitor (I use and recommend
    the Billion BiPAC 8800NL, which I monitor with DSLstats) it will tell
    you. Even without a program to monitor it, you should be able to tell
    either from the web interface or with the right incantation over
    telnet. It'll also tell you the system and dsl uptime, SNRM (in
    total, per-band, and per-tone), attenuation, error rates, depth of
    interleaving (if any), traffic flow, let you watch your data
    consumption, etc. - pretty much everything you could want to know.

    Some ISPs may have the information available if they have a customer
    page for line stats or line data - Zen don't give that level of
    detail, although I could see the increased sync rate when it was
    enabled on my line.
    Of course, it needs to be enabled on the line and your router/modem
    needs to be capable of supporting it.

    I'm hoping for a bit more when vectoring comes along (or maybe keep
    the same speed but lose the interleaving, although the depth of that
    has dropped markedly since INP was enabled, so I'm not seeing much
    penalty from that anymore).
    Phil W Lee, Mar 28, 2015
  11. Martin Brown

    Mark Guest

    I do have the aforementioned router. And INP is enabled now.
    I am a relatively long way from my street cabinet AFAIK so don't get
    particularly fast performance:

    Down Up
    SNR Margin (dB) 12.5 6.0
    Attenuation (dB) 22.0 0.0
    Output Power (dBm) 13.3 -4.9
    Attainable Rate (Kbps) 55219 8383
    Rate (Kbps) 40173 8398
    D (interleaver depth) 8 4
    INP (DMT symbol) 47.00 44.00
    Mark, Mar 28, 2015
  12. Martin Brown

    Phil W Lee Guest

    Your snrm is rather high, and your download speed very low compared to
    the max attainable. Your attenuation is only 1 dB higher than mine.
    so you should be getting a bit more speed than you are.

    Which firmware version are you on?
    I'm getting this from my stats:

    DSLAM/MSAN type: BDCM:0xa485 / v0xa485
    Modem/router firmware: AnnexA version - A2pv6F039g1.d24m
    DSL mode: VDSL2 Profile 17a
    Status: Showtime
    Uptime: 13 hours 6 min 21 sec
    Resyncs: 0 (since 29 Mar 2015 14:10:51)

    A power failure of several hours yesterday makes uptime and resyncs
    irrelevant, as I had to shut almost everything down :-(

    Downstream Upstream
    Line attenuation (dB): 21.0 0.0
    Signal attenuation (dB): Not available on VDSL2
    Connection speed (kbps): 60000 14016
    SNR margin (dB): 6.6 5.9
    Power (dBm): 12.6 7.5
    Interleave depth: 16 4
    INP: 48.00 47.00
    G.INP: Enabled

    RSCorr/RS (%): 0.8862 19,4505
    RSUnCorr/RS (%): 0.0000 0.0000
    ES/hour: 0.23 0

    Current firmware is available (if you need it) here:

    I'm about 600 metres from the cabinet, if the wet string is routed
    sensibly (so probably further than that in reality), so hardly close.

    I have taken some steps to optimise my physical connection as far as

    All my cabling from where the line enters the house was laid by me to
    gigabit ethernet standards (solid core cat6) before it was offered to
    the BT engineer when the phone was installed, so he just used what I'd
    installed for him (and was very grateful for it too - it is a horrible
    cable run to where I wanted the master socket). The (disconnected)
    phone that was still here when I moved in was wired to one of those
    lozenge shaped connection boxes with screw terminals inside (no actual
    socket at all), which shows how old it was.
    The only socket now is the master, so there is no extension cabling at
    all - I use a DECT system for that.
    The external phone line appears to be original from whenever the
    original occupier (the only one before me) had the phone installed,
    sometime (probably not long) after the house was built in the early
    50s. Overhead cables supply the house, but underground feed to the
    poles from which the overheads are strung.
    I reckon I've got mine about as good as it can be, at least until
    vectoring is rolled out.
    Your ability to do anything similar may be limited, as once the line
    is installed, the cable between the master socket and home entry
    belongs to BT, and you aren't supposed to touch it. So my putting the
    good cable in first was my gift to BT, in return for a higher quality
    connection :)

    I hope some of that is of use to you.

    Phil W Lee, Mar 30, 2015
  13. Martin Brown

    Mark Guest

    Right now my SNRM is 7.4dB.

    I am on the "up to 40Mbps" product with my ISP because my sync speed
    was lower than this recently.
    Me too. My router is connected directly to the master socket, via a
    short cable. There are no extension cables.

    The cables to my house were replaced not long ago due to a fault.
    Mark, Mar 30, 2015
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