Max DSL and line length

Discussion in 'Broadband' started by Terry_P, Feb 26, 2006.

  1. Terry_P

    Terry_P Guest

    Will the introduction of Max DSL have any effect on the current limitations
    of line length? I can only receive 1MB at present because of the distance
    from the exchange. Is there any hope that I will be able to have increased
    speed when my exchange is enabled for Max DSL?

    Terry_P, Feb 26, 2006
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  2. Terry_P

    DLMatthews Guest

    Yes, you will most probably see some sort of increase as MaxDSL is
    supposed to sync at the highest possible speed that your line is
    capable of. Currently, BT limit connection speeds based on attenuation,
    but these can be rather conservative.

    If you post your line stats from your ADSL modem, its possible to
    guestimate the approximate speed your line is capable of. Its the SNR
    (Noise Margin) & Attenuation thats needed.
    DLMatthews, Feb 26, 2006
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  3. Terry_P

    Mugwump Guest

    Or do it yourselfe here:-
    Mugwump, Feb 26, 2006
  4. Terry_P

    Ian Stirling Guest

    However, it asks for SNR, whereas some modems report SNR margin.
    Is there a simple conversion? Add 2dB for example?
    Ian Stirling, Feb 26, 2006
  5. Terry_P

    Terry_P Guest

    Thanks. How do I check my line stats? I'm using a Netgear DG834G and when I
    log in I don't see anything relevant. Do I need some other software?
    Terry_P, Feb 26, 2006
  6. Terry_P

    Beck Guest

    Likewise my router does not have a figure for SNR, but has DS and US
    margins. Would that be the same?
    Beck, Feb 26, 2006
  7. Log on to the Netgear Router
    Goto Router Status Page.
    At bottom of page click on Show Statistics. New window opens with the info.
    Paul Woodsford, Feb 26, 2006
  8. Terry_P

    DLMatthews Guest

    Its the DS (Downstream) statistics you're after.
    DLMatthews, Feb 26, 2006
  9. Terry_P

    ukdiyuser Guest

    Max DSL isn't an improved technology, it's simply BT relaxing their own
    guidelines as to what speeds they will support for a given line
    attenuation. These guidelines have previously been set on the low side,
    reportedly to give what BT regarded as an acceptable level of
    reliability, but also perhaps with a view to being able to relax them in
    order to sell a new 'Max DSL' product to maintain competitiveness
    against growing customer interest in LLU products.

    So yes there is certainly a chance that you will be able to get higher
    speeds, but possibly at the expense of reliability, and nothing you
    couldn't already get from an LLU ISP if you were lucky enough to have
    LLU support at your exchange.
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    ukdiyuser, Feb 26, 2006
  10. Terry_P

    Terry_P Guest

    Thanks for your reply, Paul.
    When I do what you suggest all I see is a table headed System Uptime with
    columns headed Port, Status, TxPkts, RxPkts, Collisions, TxB/s, RxB/s and
    Up Time. I'm using firmware Yes, I know there are later
    versions but this one works very reliably for me.
    Terry_P, Feb 26, 2006
  11. Terry_P

    Terry_P Guest

    Later: I've upgraded the firmware to v 1.05 and can now see the line stats.
    Terry_P, Feb 26, 2006
  12. Terry_P

    Terry_P Guest

    Here are my line stats at 1152 kbps:
    Line attenuation 48db
    Noise margin 22db

    What do you think?
    Terry_P, Feb 26, 2006
  13. Terry_P

    Daniel Guest

    You should be able to have a reliable 2Mb connection, possibly as much as

    Daniel, Feb 26, 2006
  14. Terry_P

    DLMatthews Guest

    Based on those stats, using ADSL1 technology (which is what MaxDSL is)
    the max your line could support is approx 4-4.5Mbps. It depends on
    what BT are setting the "target SNR" as on this new MaxDSL service, as
    that will be what determins your sync speed. I reckon at worst, you'll
    be looking at 3Mbps.

    When ADSL2+ comes along (well, its already here if you have an ISP with
    their own equipment installed at the exchange using LLU), you'd see a
    slight increase in sync speed on top of that above..
    DLMatthews, Feb 26, 2006
  15. Terry_P

    Terry_P Guest

    Thanks for your replies DLMatthews and Daniel. Very helpful.
    Terry_P, Feb 27, 2006
  16. Terry_P

    pzboyz Guest

    My exchange has just been MaxDSL enabled, and my SNR has dropped from
    about 15db to 6db, attenuation is 55db and line speed has stay fixed at
    1152kb/s. Nothing has changed at my end of the connection.

    Any reason why BT carrying out 'the work' would have reduced my SNR?

    pzboyz, Mar 20, 2006
  17. Terry_P

    kráftéé Guest

    More probably part of your cable has been changed due to uplift works,
    or your neighbour has bought a big shiney new plasma TV, or your PC
    power supply is starting to throw a wobbly, same for your router power
    supply. There are a lot of things which can affect your SNR, the
    majority of them happen to be outside BT's control...
    kráftéé, Mar 20, 2006

  18. It reminds me of that old not the nine o'clock news spoof sketch where
    the BBC were being blamed for no milk in the fridge and tripping over
    the pavement. 'It is not the fault of the BBC'. That said the latter
    could well be the fault of BT.......
    Daniel Richards, Mar 20, 2006
  19. Terry_P

    Euan Guest

    How long have you worked for BT?

    Euan, Mar 20, 2006
  20. Terry_P

    kráftéé Guest

    Not long enough for a decent pension but to long to keep my sanity
    kráftéé, Mar 20, 2006
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