ADSL line speeds how can you tell your max? UPDATE [Archive]

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Marek

11-07-2005, 15:50

Just recently joined a new broadband supplier offering upto 2mb(they will give you fastest available on your line), i have been connected at 1mb and they claim this is the fastest my line will run although i am sure bt have offered me 2mb on my line and my neighbour runs on 2mb also. Is there any url's or any services that can do a check to see what is the max speed i can get out of my line? :shrug:

Just curious about this..

Thanks

kungfuman

11-07-2005, 15:54

http://www.adslguide.org.uk/tools/speedtest.asp

Chris Locke

11-07-2005, 16:13

samKnows.com (http://www.samknows.com/broadband/checker2.php) was quite a useful site - it works out how far you are from your exchange so tells if you can actually get a 2MB connection. Eg, for me, I'm 2.97km from the exchange, so out of range. :(

Dave h-j

11-07-2005, 16:20

Not really - their are speeds tests (like the one above) that will tell you the current speed of your line, but you know that anyway..

The criteria for ADSL speed is a combination of Attenution (amount of signal loss) and SNR (the signal-to-noise ratio which is a measure of signal strength compared to noise on the line), these are both factors of line length and environment..

For 1Mbit the attenuation "limit" is 60dB and for 2mbit is it 43-45dB (depending on whether adsl is already active or not).

For SNR, the accepted minimum is 6dB at the required speed, but be aware that moving up speed level will result in a drop in SNR or approx 6dB..

This means that if you current stats are, for example, attn 44dB and SNR 15dB, then you should be able to get 2mbit, if you have 55dB and 10dB then you won't..

These are not hard and fast rules, and you may find that someone quoting 58dB and 18dB are on 2mbit..

If your stats are generous, then you could ask your ISP for a manual regrade, to see if BT would be willing to up the speed, although if you are outside the guideline limits, then don't expect them to bend over backwards to get 2mbit to work..

If you stats are poor, then try connecting your ADSL modem to the master sockets test socket, to eliminate and internal wiring problems. This can provide a more stable ADSL connection.

Marek

11-07-2005, 20:31

Dave h-j

11-07-2005, 20:58

thanks for the handy info dave i have a 43db line attentuation and a 9db noise margin which is pretty static, connection speed of 1152kbsec which with my last isp was 2048 but only had 1mb due to only buying that bandwidth

cheers

Ah yeah - whilst 43dB is good enough for 2mbit, an SNR of 9dB would all but disappear after an upgrade to 2mbit. Are you plugged into the master socket? This could increase your SNR...

raymondlin

11-07-2005, 21:07

Ah yeah - whilst 43dB is good enough for 2mbit, an SNR of 9dB would all but disappear after an upgrade to 2mbit. Are you plugged into the master socket? This could increase your SNR...

Operation Data Upstream Downstream
Noise Margin_____23 dB_____14 dB
Attenuation_____63 dB______54 dB

I am on 1mb at the moment, you think i can get 2mb with those numbers?

Dave h-j

11-07-2005, 21:30

Operation Data Upstream Downstream
Noise Margin_____23 dB_____14 dB
Attenuation_____63 dB______54 dB

I am on 1mb at the moment, you think i can get 2mb with those numbers?

Well at 54 and 14, you would be pretty lucky. 54dB is beyond the limit, but people have reported being connected at 54dB. The SNR of 14dB, would drop to around 8dB, which is starting to reach the limit. If your SNR was solid, then you possibly would, but if it varied during the day (as sometimes happen, as not all noise is constant) then you may find you get disconnections..

BT(wholesale) probably wouldn't - but stranger things have happened. You may have more luck with an LLU, especially one that uses rate-adaptation to match the line conditions, but it isn't a given..

In the end though, you may be trading stability for speed..

raymondlin

11-07-2005, 21:34

Well at 54 and 14, you would be pretty lucky. 54dB is beyond the limit, but people have reported being connected at 54dB. The SNR of 14dB, would drop to around 8dB, which is starting to reach the limit. If your SNR was solid, then you possibly would, but if it varied during the day (as sometimes happen, as not all noise is constant) then you may find you get disconnections..

BT(wholesale) probably wouldn't - but stranger things have happened. You may have more luck with an LLU, especially one that uses rate-adaptation to match the line conditions, but it isn't a given..

In the end though, you may be trading stability for speed..

Ta, guess i'll stick with 1mb then. I do notice now and again my connection drop, may be that's why !

Marek

11-07-2005, 23:06

I am not using the master socket using the sparre bedrooms. The master socket is in a silly place next to the front door :( and running a line aint to easy, but may check it for stats

cheers

Marek

13-07-2005, 07:45

Got this reply from plus.net

Dear Mr Halpin, looking back on your ticket. you state that your line attenuation was 43 DB? you are required to have 42 DB or less to be able to revieve 2mb adsl. this would be the reason that you are not able to get 2mb. However if the limits for 2mb increase we can look at regrading you line to 2mb.

Regards,

Leon Burton

Is this true ?

Mr_Gimp

15-08-2005, 18:19

Resurrecting this thread for a bit of advice, has anyone tried asking for a manual regrade from UKOnline? I'm on one of their LLU exchanges (Cambridge) and their availability checker quoted 512k as the fastest connection I could get. Just got connected and my router reports (downstream) SNR of 31 db and attenuation of 37 db.

Prufrock

15-08-2005, 21:54

Downstream Upstream
SNR Margin (dB): 23.1 26.0
Attenuation (dB): 11.5 8.0

That's me. I'm really close to the exchange, though. Can still only get 2MB max, thou

Dave h-j

15-08-2005, 22:27

Prufrock

15-08-2005, 22:40

I don't see why, those lines (prufrock and Mr Gimp) are capable of a lot quicker..

BTWholesale has a 2mb limit atm, but other LLU operators should be able to offer faster speeds that you currently have..

I can only get BT Wholesale right now, that's why. :( My local exchange hasn't been unbundled yet.

Marek

16-08-2005, 11:49

Got int touch a few weeks back with a very good representitive for plus net and they upgraded my line to 2mb on 43db and its all good, no drop outs and constant 200-240kb/sec

Big up for plus.net

manicmic

16-08-2005, 20:57

Here's something to play with.

http://www.farina1.com/calc.htm

TELREA

17-08-2005, 00:04

Here's something to play with.

http://www.farina1.com/calc.htm

crap im on 512 forever

TEL.

mwd2000

17-08-2005, 15:34

adam.mt

17-08-2005, 16:00

Until a month ago was stuck on 1mb because apparently my line wouldn't support any more. Well Freedom2Surf recently changed their service offers so I've gave the 2mb option I go (it offered unlimited downloads anyway rather than the capped I was on). Well a few days later I got a 'success' e-mail, which surprised me!

Current stats are (according to my ADSL router):
Line speed: 2272 Kbps
Noise margin (SNR): 11 dB
Output power: 18.5 dBm
Attenuation: 54 dB

....the exchange is going LLU with f2s later this month, wonder if I'll get a speed boost? (f2s offer up to 8mb via LLU for same cost).

Dave h-j

17-08-2005, 17:23

Hmm, my attenuation is 65.5 and SNR is 12.

The farina.com link states that my line is possibly capable of 912kbps but Samknows / BT state that I'm limited to 512k.

My ISP is BT Broadband. What are the chances of BT upping me to a 1Mb connection?

None.

BT don't offer a 912kbps service, so you would be outside the capabilities of the line, even by farina's guesstimate...

In reality, farina is just an estimate based on SNR, and doesn't take any other factor into consideration. An upgrade to 1mb, would drop your SNR to ~6dB, which means it would probably drop out quite frequently..

Dave h-j

17-08-2005, 17:25

....the exchange is going LLU with f2s later this month, wonder if I'll get a speed boost? (f2s offer up to 8mb via LLU for same cost).

It'd be touch and go, but you may well get 3mb. Might be worth a try to see if it works, although I wouldn't get my hopes up.

adam.mt

17-08-2005, 18:47

Re-reading my post, I see I didn't make the point I wanted to make clear - in my experience the requirements for various speeds have changed in the last few months, hence why my line was previously said to only support 1mb (about 6 mths ago I made this change) , but for the last month has now been upgraded to 2mb.

Hoskas

17-08-2005, 19:04

silly question, but how do i find my attenuation and snr?

My netgear router doesnt seem to have that information available

Mr_Gimp

17-08-2005, 19:07

On mine, i go to the "router status" page, and at the bottom there's a button that says "show statistics". It pops up a window with Noise Margin (SNR) and Attenuation, amongst other things.