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A Shiny New Broadband Sticky

Discussion in 'Networks & Internet Connectivity' started by tolien, Jan 26, 2006.

  1. tolien


    Joined: May 16, 2003

    Posts: 25,368

    Location: ::1

    Last edited: Feb 17, 2006
  2. tolien


    Joined: May 16, 2003

    Posts: 25,368

    Location: ::1


    thinkbroadband (previously ADSLguide)- infinite supply of ISP information.


    BT - Postcode and Phone number checker, straight from the horse's mouth.
    Samknows - LLU data, straight line distance to your exchange. Not all up to date.
    ADSL maximum line speed estimator - courtesy of MrSaffron (of ADSLguide fame).

    Before you post a query about your ADSL connection, you would be very well advised to try and get stats out of your router.
    You can find instructions for doing that at http://www.kitz.co.uk/adsl/frogstats.htm for one.
    The important parts of these stats are your attenuation, SNR margin and sync rate.

    In this context, attenuation is the loss of signal as it passes along a cable. It's a function of both the length of the cable and the material it is made of (as well as the material and number of joints in the cable). Lower is better.
    Previously, BT Wholesale used attenuation to define the maximum speed which is available to you.
    The limits are:
    No limit (“try it and see”) for 512 kbps
    63 dB for 1 Mbps
    43 dB for 2 Mbps

    The rules still apply for fixed-rate connections, but those are few and far between these days.
    Attenuation isn't measured when you order but guessed at based on planning records at BT - obviously this is a poor arrangement.

    The distance between you and the exchange is a pretty worthless measure. It relates loosely to your attenuation, but not completely (different “features” of your line can kill the relationship stone dead). Samknows gives a straight line distance between you and the exchange, but it’s pretty worthless too.
    It is a value best forgotten about because it can mislead you into expecting results which are not sensible.

    SNR margin
    SNR, or signal to noise ratio, is defined (again, by Wikipedia) as the power ratio of signal and background noise received.
    There is no “limit” on your SNR, but at a low enough level, your modem will disconnect. Higher is better.

    Sync rate
    Your sync rate is the speed your modem connects at and in most cases won't be the same as the values you'll get from speedtests. On a rate adaptive product, it'll vary inversely with your SNR margin (i.e. SNR margin goes up, sync rate does down).
    Last edited: Dec 19, 2006
  3. tolien


    Joined: May 16, 2003

    Posts: 25,368

    Location: ::1

    MaxDSL is BT Wholesale’s greater-than-2Mbps scheme, official title IPStream/DataStream Home/Office Max.

    Right now (January 2006) it’s in beta testing, on 25 exchanges, expanding to 53. Note these details may change.
    Based on this, it will feature a download rate which ranges from 288 kbps to 8152 kbps, in (currently) unknown increments – quite probably 128 kbps. Office products feature an increased maximum upload rate over Home – 832 kbps versus 448kbps.
    A device known as a RAMBO will manage speeds, based on your connection in (approximately) the first week. This system will replace the Guesstimator, and thus you’ll get something closer to the maximum speed your line can support.

    Speed issues
    If you’re having speed issues, the first thing to try is to try at different times of day (early morning, late night, etc), using a service which you know has a lot of bandwidth, is within the same country as you, and has a reasonably big file to download (more than 10 MB is good).
    One example would be this, or perhaps the UK Mirror Service.

    If that’s slow as well, the next thing to try is the BT Speedtester if you’re using an IPStream-based service.
    You can find instructions for using it at Plusnet's website and there's also a guide on Zen's support pages.
    The most useful part of this test is that it'll give your IP profile, which limits the maximum speed you'l be able to download at.

    If you aren't using BT Wholesale IPStream (ie you're on LLU, DataStream etc), your options are a bit limited. All you can really do is make sure it isn't local to you, run speedtests at different times of day and contact your ISP.

    LLU, Local Loop Unbundling, is a process whereby another provider installs their own equipment in your exchange, and thus the provider is able to offer services which BT currently don’t (or won’t), including ADSL2+.
    Current providers are Easynet/UKOnline, Bulldog and Be. Pipex have, in the past, mentioned an LLU operation, as have AOL, but no sign of anything. Zen Internet have one running on the Rochdale exchange, where they’re based.
    Samknows has some availability data, but you’d be best checking with the respective providers’ sites.

    DataStream and IPStream are two different products provided by BT Wholesale. DataStream gives more control to the provider, which might (or might not) be a good thing. ADSLguide gives a good summary of the situation.

    The common way to determine if your connection is via IPStream or DataStream is if you change your username to bt_test@startup_domain (no/any password required). If you are on IPStream, the login will work and you will be assigned a BT IP address. If you are on DataStream, the login will fail. However, there are the odd case where this isn’t the case.

    To migrate between IPStream ISPs, you simply get a MAC (Migration Authorisation Code) key (which will begin with four letters, followed by a series of numbers and letters in two groups, separated by a forward slash) from your current ISP.

    Give this to the ISP you wish to move to, and in (approximately) 7 days (or around the day you nominate to be migrated), you should be able to change username to that for your new ISP and everything works. Downtime should be minimal.
    It’s also now possible to migrate between LLU and IPStream, without having to go through either the cost or downtime of cancelling and reconnecting your ADSL service. There will be some downtime moving between the two because there's some manual work involved.
    Last edited: Sep 13, 2006
  4. tolien


    Joined: May 16, 2003

    Posts: 25,368

    Location: ::1


    Samknows has some availability data but its accuracy is not guaranteed so you're better checking directly with the provider in question. Virgin Media is virtually the only cable provider in the UK.

    http://homepage.ntlworld.com/robin.d.h.walker/cmtips/ has a load of useful information.

    MAC address registration
    There is no longer a requirement to register MAC addresses. It’s (apparently) the case that you can use up to 4 MAC addresses per period of 4 hours.
    To change MAC address (new PC, new router, whatever), switch your cable modem/set top box off, connect your new device (leaving it off), switch your modem on, wait for the lights to stop flashing, and switch your device on. Everything should then work.

    Cable Modem Web Interface
    Some cable modems have a web interface, with all sorts of (mostly useless) data. Information here.
    Last edited: Jan 27, 2006
  5. tolien


    Joined: May 16, 2003

    Posts: 25,368

    Location: ::1


    When you’re buying a router, beware of the distinction between hardware claiming to be for “ADSL”, and hardware claiming to be for “DSL/cable” or “broadband”.
    ADSL routers won’t work on cable as a router at all but "cable routers" won’t work on ADSL without an additional ethernet ADSL modem to take the place of the cable modem.

    Routers intended for cable, i.e. without a modem, require the cable modem you got from the cable company to work - they do not replace the cable modem.
  6. tuomoy


    Joined: Jan 9, 2010

    Posts: 137

    Virgin used to require MAC registration but then stopped few years ago.
  7. Engram


    Joined: Jul 6, 2004

    Posts: 978

    Location: England

    Damn, this "shiny new" sticky is so out of date. :eek:
  8. kaka4200


    Joined: Jul 8, 2014

    Posts: 165

    Really helpfull sticky, thnx !
  9. Gambisk

    Wise Guy

    Joined: May 22, 2013

    Posts: 1,229

    Location: N. Ireland

    would someone be able to update this with more up to date information, I'm looking to switch services pretty soon and haven't much idea of what to look for.
  10. MissChief


    Joined: Jul 17, 2010

    Posts: 17,407

    Clearly not. It should be removed completely IMO.