Speed Chechers Up the Spout

[#1]

How can BT's PN , ADSL24 , availibility checkers be so wrong , i understand they get this information from BT database , but wow if only they were correct for once, and i know this line has a 60db loop loss on ADSL2+ 

Quote

For Telephone Number 01908*** on Exchange MILTON KEYNES Your exchange is ADSL enabled, and our initial test on your line indicates that your line should be able to have an ADSL broadband service that provides a fixed line rate up to 2Mbps. Our test also indicates that your line currently supports a potential ADSL Max broadband line rate of 6.5Mbps or greater. Our test also indicates that your line currently supports a potential broadband line rate of 9Mbps or greater.

Someone somewhere , must have the know how to be able to setup a good , reliable line checker so they know exactly what speed they will get. If i had just gone to sign up on this info i would be a bit miffed when activation date came and i could only get half  :-\.

[#2]

If you use the Post Code checker version does it return with the sam figures? http://www.dslchecker.bt.com/adsl/ADSLChecker.postcode

[#3]

mine changed since i upgraded to adsl2 but before was 2.5mb adsl and 2.5mb adsl2.
now its adsl 3.5mb and adsl2 4.5mb
before on adsl  i had atten of 51db and max stable profile of 3000kbps on adsl2 thats now 50db 2500kbps profile due to the msan increasing my noise margin target to 15db from 12db on adsl
4.5mb yeah in my dreams.  
seems like BT  have reset all the est's to 6db margins. if this stays like this when PN roll out adsl2 new customers given there est of speed on sign up will be very disponited punters when there lines perform alot less then the est and PN will be who they shout at not BT. due to the est being from PN but PN get it from BT

[#4]

Postcode checker still returns higher than the original lol , not as high as the phone number check though , 512 , no 1mb service .

Quote

Your exchange is ADSL enabled, and our initial check on your postcode indicates that your line should be able to have an ADSL broadband service that provides a fixed line rate up to 1Mbps. However due to the length of your line the 1Mbps service may require an engineer visit who will, where possible, supply the broadband service. Our check also indicates that your line currently supports a potential ADSL Max broadband line rate of 3Mbps or greater. Our check also indicates that your line currently supports a potential broadband line rate of 3.5Mbps or greater.

EDIT
I thought the actual phone number chech was more reliable than the postcode check though. Not sure whats happened there , but its happening on my other number too (plusnet line)

[#5]

Post Codes are *always* in the same place.
Phone numbers can move around.  I'd expect the Post Code check to be more accurate, personally.

[#6]

I used http://www.kitz.co.uk/adsl/adslchecker.php earlier and its spookily accurate:
Exchange: Hayle. BT Code: WWHAYL
Location: Foundry Square, TR27 4HQ
Distance:- Direct:    707 metres
  (appx)* By Road: 1.45 km
  Status 
ADSL enabled : August 20, 2003
DSL Max enabled:  March 31, 2006
SDSL enabled : Not Enabled
21CN due : (PSTN) No Info
21CN WBC (Broadband) RFS date 31.03.11
  Broadband Access†

Fixed ADSL:  2048 kbps (2 Mb) 
DSL Max :  8000 kbps (8 Mb) 
  21CN WBC : 14000 kbps  (14 Mb) 

Important: The above figures are obtained from the BTw database, which is often conservative.
DSLmax speeds are best guess based on the surrounding area and cannot take into effect individual line conditions which may effect the result such as the type of equipment you use or other issues which may affect the Signal to Noise Ratio.
Wow, I've been with F9's ADSL since August 2003, 6 years, and before that dial up.  Wonder if Ladbrokes would gimme odds on if I'll be with them for another 6 years, I'd put my money on it

[#7]

Quote from: dgwebb

I used http://www.kitz.co.uk/adsl/adslchecker.php earlier and its spookily accurate:

Not so for me, it's woefully inaccurate:

Quote from: BT

Fixed ADSL:  1024 kbps  (1 Mb) DSL Max :  1000 kbps (1 Mb) 21CN WBC : 1000 kbps (1 Mb)

I'm only 2.25km away from the exchange by road and my downstream line attenuation is 37db. Even with a 15db target SNR I'm still synchronising above 4Mbps. My old house is an extra kilometre away from the exchange and that gives me the following:

Quote from: BT

Fixed ADSL:  2048 kbps  (2 Mb) DSL Max :  6000 kbps (6 Mb) 21CN WBC : 8000 kbps (8 Mb)

Go figure 

[#8]

Bob, why are you saying Kitz's calculator is inaccurate - it looks pretty well spot on for your 37db. You have a high noise margin so your speed is below the calculators prediction.
The guestmated line length is very close as well.
I think the wrong URL was given - try http://www.kitz.co.uk/adsl/max_speed_calc.php

[#9]

I use that 2nd url too, but that one is a little off for my speed.  I'm synching at 8128 whilst the 2nd url puts me at 7905 with a profile of 6500, my actual profile is at 7150.  My best guess is that because my line is new, they either used fibre (unlikely) or lots of nice new sparkly copper, distance is off by about a kilometer too.  That kitz site is a veritable minefield of useful information though!

[#10]

Working Great here!

/showing off

[#11]

Quote from: jelv

Bob, why are you saying Kitz's calculator is inaccurate - it looks pretty well spot on for your 37db. You have a high noise margin so your speed is below the calculators prediction. The guestmated line length is very close as well.

I was questioning the accuracy of the exchange check that queries BT's database records.

[#12]

I thought it was common knowledge that the BT database was crap.
I know Kitz does some excellent work, but expecting her to translate data obtained from the BT database in to accurate predictions is a bit much!

[#13]

I personally have found http://www.kitz.co.uk/adsl/max_speed_calc.php to be pretty well spot on.
As for the BT database, well you've already said it John.