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BE Internet 24MBit in London

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BE Internet 24MBit in London

Any plans for this to be rolled out right across the board in the not to distant future by PlusNet?
18 REPLIES
Firejack
Grafter
Posts: 921
Registered: 26-06-2007

BE Internet 24MBit in London

24Mbit is being provided by several of BT's competitors such as Easynet. Now since Plus.net is solely supplied by BT I doubt we'll be getting ADSL2 (24Mbit) anytime soon.
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BE Internet 24MBit in London

i guess you have to first wait for 8mbit from BT which people are saying is coming out early 2006
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I'd move...

Well, if the service was open to me where I live I would move despite the fact that Plus.net have been good to me.
The potential 1.3Mb upload would make a world of difference for MMO gaming and that's just something I couldn't ignore.

So Plus.Net if you're listening I'd advise getting LLU sorted as soon as possible if you don't want to lose the online gaming market!
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BE Internet 24MBit in London

It's not just London. My exchange in Manchester should be enabled in October - can't wait for that to happen!

It will certainly make working for home even more attractive Cheesy
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BE Internet 24MBit in London

Do any of your guys know your line stats.

Speed figures I have seen suggest the fastest so far is a little over 17Mb/s sync speed, and that was pretty much living in the exchange.
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BE Internet 24MBit in London

Not sure how to get the Line Stats out of my Belkin Router (Suggesions welcome! They're not on the Web GUI anyway...)

I comfortably get 2mb ADSL and am roughly 2.5km from the exchange. From a site I saw with ADSL2 Stats, I think it should get me in the range of 15mb Cheesy
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BE Internet 24MBit in London

When I said living on top of the exchange, I mean your able to see it, without climbing to the very top of your room.

What technology says it can do on paper, is never what it can do in the real world.

ADSL is testiment to that.

2Mb ADSL on paper, should work comfortably above 43dB. However, we are now seeing BT starting to reject anything over it (ie, no more 45Db limits). This is all caused on by the increased reports of line instability, on what on paper should work.
Community Veteran
Posts: 2,322
Registered: 01-08-2007

BE Internet 24MBit in London

Its probably also partly because BT are pretty useless at support.

Looking at the speeds achieved by any number of people that are with LLU providers will show that 43db attenuation is wayyy to conservative.

Besides its not really the attenuation that counts - its the SNR. More modern equipment doesnt give a stuff about how quiet the signal is (attenuation) but more about how good the signal is (SNR).

However what BT do is say, 43db attenuation on a standard run of copper wire, with an old usb adsl modem should be OK. That way they are assured of a minimum number of support calls/conflicts.

Those moving to LLU for higher speed represent a much smaller number of users, and usually have better equipment than a bog standard Zoom ADSL modem from PC world.

The general rule of thumb is - for every doubling of your line speed, take off 6db from your SNR, and try not togo below 10, although some people report steady connections with anything as low as 4db SNR (which is very very lucky indeed). Once you get above 4mb, then you probably need to prepare to lose more than 6db for every line speed doubling, and beyond the 8mb, who knows - but you are going to need a very SNR on 2mb to even dream of stuff beyond 16mb.

take my line as an example: (and this is taking 6db per doubling as a standard rate, which above 4mb is probably more like 7 or 8db)

512k SNR=28 (what I used to be on)
1mb SNR=21 (this is what I have now)
2mb SNR=15
4mb SNR=9 (dodgy territory)
8mb SNR=3db (not a hope)
16mb SNR=-3 (wont even sync)

Now take a decent 2mb connection: and lets say that above 4mb you need 8db of SNR for each speed doubling:

2mb SNR =30db
4mb SNR=24db
8mb SNR=16db
16mb SNR=8db (dodgy territory)

As we have no experience of these speeds on the general UK network yet, we cant make any assumptions, but I reckon the above will be pretty close.

There is much more to speed than simply your attenuation (loop loss due to line length) - if you live in a newly developed area, then it is likely that you cables to the exchange are nice shiny new ones in nice newly sealed pipes. So while you may have a high attenuation (like myself) you may have a decent SNR in comparison (like myself).

Its this fugure that will come into lay more and more with the advent of faster speeds, along with more sensitive equipment in order to allow lower SNR's to provide a stable connection.
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BE Internet 24MBit in London

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The general rule of thumb is - for every doubling of your line speed, take off 6db from your SNR, and try not togo below 10

This is the same principle as I learnt in my audio engineering course isn't it? Because resolution in a digital signal is to do with the bit depth and each 6dB of dynamic range allows you to increase the bit depth of the signal by one bit (eg. CD music is 16-bit and so has 96dB dynamic range).

However, I do think that this is about to change with MaxDSL and ADSL2+. It will not be as simple as this when these kick off since these technologies start to use even higher frequency spectrums on your line so you no longer have a single SNR figure to deal with. I'm not completely sure of this though so if anyone wants to correct me, feel free.
Community Veteran
Posts: 2,322
Registered: 01-08-2007

BE Internet 24MBit in London

Im not basing it on anything specific, it jut seems to be the rule of thumb for ADSL speeds beyond 2mb - but to squeeze that last bit out of the line up to 8mb, then more SNR "availability" (for want of a better term) is needed.

Im guessing that as you go beyond 4mb/8mb, the drop in SNR for each speed bump may start to deviate from a straight line graph - the jump from 8mb to 16mb may need a much higher quality line.

I suppose we have to wait and see. Without much more advanced technology there is in my opinion, realistically little hope of seeing the full benefit of 24mb speeds for tha vast majority of ADSL customers - BT trialling fibre to the cabinett sounds interesting, that would certainly seem like the way forward to bring ludicrously high speeds to everyone - but the cost and scale of such a project at present would render it very much pie in the sky for now.

I suppose we have to wait and see what happens!
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BE Internet 24MBit in London

Be will be doing the Chichester exchange in April next year apparently, so if no-one else upgrades the exchange then, I know where I'm going Smiley
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BE Internet 24MBit in London

Be must be doing a lot of exchanges as they're doing my exchange (Coatbridge) in December. BT had us near the end of the list for introducing ADSL here so didn't expect it so quickly Cheesy
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BE Internet 24MBit in London

well before they upgraded, my SNR was around 43, but had 2mb comfortably, now, its at 31, does that mean anything to anyone, apart from it being better I mean
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BE Internet 24MBit in London

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Do any of your guys know your line stats.


Managed to get mine out of my Belkin router via Telnet. Not sure what they mean, so any help appreciated!

LocalSNRMargin 24.0 dB
LocalLineAttn 29.0 dB
RawAttn 29.0 dB
LocalTxPower 11.5 dB
RemoteLineAttn 16.5 dB
RemoteSNRMargin 31 dB

Are these good or bad? I currently get 2mb ADSL, but have signed up for BE (If they ever enable my exchange!)