Exchange activation and speed limitation

[pazzaTgreat]

Here is an interesting link I found on ADSLguide

http://bbs.adslguide.org.uk/showthreaded.php?Cat=&Board=idnet&Number=2457264


Now this is very interesting because I have been asking loads of people why my perfect line stats are never getting better than 6-6.5Mbps.  I eventually phoned BT wholesale after Miriam had raised a slow speed issue but as usual BT rejected it and they claimed my line would only support up to 6.5Mbps. 

They lie as their own checker actually indicates my line should support IN EXCESS of 6.5. 

The very best throughput I have ever got is 6.5 ish.  This exchange information checker shows up that my line has only had 6.5 activated.  I sync rock solid at 8128 all the time with a downstream margin in excess of 10 all the time. According to the responding email from Miriam my max stable rate is 8128 and top throughput should be around 90% of this which is around 7.15Mbps.

 Therefore I don't understand, unless this is actually an exchange limitation for throughput.

Can anyone else try this checker and report their line settings?

ADSL Line check

Telephone number :    XXXXXXXXXX
BT exchange :    XXXXXXX
Real time check :    Yes

Line speed capabilities

      Rate adaptive (250k and 500k) :    Green
      Fixed Rate (1000k and 2000k) :    Green
      MAX speed (upto 8000k) :    Green (6500 kbps)

      250k, 500k, 1000k, 2000k and 6500k are all available on this line.


Line status

      This line has ADSL fully installed on it. There are no open orders currently on this line.


Exchange status

      This exchange is fully enabled for rate adaptive (500k) ADSL, fully enabled for fixed rate (1000k and 2000k) ADSL, and fully enabled for Max ADSL (upto 8000k).

      There are 1 DSLAMS in the XXXXXXXX exchange

      DSLAM name   ADSL enabled   SDSL enabled   Daily port usage   Spare ADSL ports   Spare SDSL ports   Short term available ports   Long term available ports   Available bandwidth (Mbps)   In service date
      TGT_DSL_101   Yes   No   0   101-125   0   0   1001-1025   110-120   Now

[Adam]

A few questions first off;

What times exactly are you testing here?
Did you use the BT speedtest login?
What are your actual download speeds?

The BT exchange checker isn't anything definitive, it's an estimate based on a number of factors.

Adam

[Coopes]

mine this morning at 8:25

ADSL Line check

Telephone number :  xxxxxxxxxxx
BT exchange :  xxxxxxxxxxx
Real time check :  Yes

Line speed capabilities

Rate adaptive (250k and 500k) :  Green
Fixed Rate (1000k and 2000k) :  Amber
MAX speed (upto 8000k) :  Green (3500 kbps)

250k, 500k and 1000k ADSL is available on this line. 2000k ADSL is not likely to be available on this line.250k, 500k, 1000k, 2000k and 3500k are all available on this line.

Line status

This line has ADSL fully installed on it. There are no open orders currently on this line.

Exchange status

This exchange is fully enabled for rate adaptive (500k) ADSL, fully enabled for fixed rate (1000k and 2000k) ADSL, and fully enabled for Max ADSL (upto 8000k).

There are 8 DSLAMS in the xxxxxxxxxxx exchange

[pazzaTgreat]

A few questions first off;

What times exactly are you testing here?
Did you use the BT speedtest login?
What are your actual download speeds?

The BT exchange checker isn't anything definitive, it's an estimate based on a number of factors.

Adam

This was done at about 1am when I get my best speeds.

I have done all the other checks Adam, see other posts about speeds etc.  I have had varying BT checks from 600kilobit to 5 megabit but mostly my measured throughput is between 4 and 6 megabits. 

*This checker isn't for speed, it's for line and exchange stats.*

My point was this is the first exchange check ever to show that my line is set at 6500, no-one else in the chain has ever said this, but it would bear out my speed observations.  I cannot understand given my line stats of

permanent non-dropped sync of 8128 down
SNR margin permanently 10+ down
max attainable rate of 10megabits plus reported by the modem

BT claim my max stable rate is set at 8128

If, my max stable rate is 8128, throughput should *at some points of the day* match this, (given the max of 7.15Mbps)  if only in bursts.  It has never ever ever ever gotten better than 6ish megabits and a line speed of 6500 would explain this.  What I don't understand is what relation the line speed is to the sync rate, because on the basis of the sync and noise rate, and being only 300m from the exchange I should see top rates at least sometimes.

I am asking if anybody knows if the exchange equipment still somehow posts a throughput (data) rate on your line because I know some people with lesser line stats are getting better throughput in different locations.

whew - that was a big post!!!

[pazzaTgreat]

mine this morning at 8:25


Rate adaptive (250k and 500k) :  Green
Fixed Rate (1000k and 2000k) :  Amber
MAX speed (upto 8000k) :  Green (3500 kbps)

250k, 500k and 1000k ADSL is available on this line. 2000k ADSL is not likely to be available on this line.250k, 500k, 1000k, 2000k and 3500k are all available on this line.

Mark - does the indicated 3500kbps match what you see as throughput??

[Bill]

If, my max stable rate is 8128, throughput should *at some points of the day* match this, (given the max of 7.15Mbps)  if only in bursts.  It has never ever ever ever gotten better than 6ish megabits and a line speed of 6500 would explain this.  What I don't understand is what relation the line speed is to the sync rate, because on the basis of the sync and noise rate, andbeing only 300m from the exchange I should see top rates at least sometimes.

Not necessarily. My stats are 8128/448, noise margin generally around 12dB. Highest data rate I've ever seen is about 6,600Kbps (here) which is about right.

Theoretical max is about 7200, but that pretty much assumes that nobody else is using any of the servers between you and your target. Any other traffic or exchange contention is going to slow you down a little, at some times of the day my speed can drop below 2000Kbps for brief intervals. Average is probably around 4000Kbps.

6500Kbps is a good speed, don't knock it 

[pazzaTgreat]

Not necessarily. My stats are 8128/448, noise margin generally around 12dB. Highest data rate I've ever seen is about 6,600Kbps (here) which is about right.


6500Kbps is a good speed, don't knock it 

Ah - but the point I'm making isn't about the actual speed Bill, it's about the line rate set at the exchange - I have the same stats ish as you but you are getting better throughput but this checker has shown my line to only support 6500.  This has never been intimated before, and if I sync at 8128 why is my line rate 6500?  I am on a quest for knowledge, not complaining!!!!

If you do this check, with the same stats - what does it show your line rate as?

[Adam]

Ah - but the point I'm making isn't about the actual speed Bill, it's about the line rate set at the exchange - I have the same stats ish as you but you are getting better throughput but this checker has shown my line to only support 6500.  This has never been intimated before, and if I sync at 8128 why is my line rate 6500?  I am on a quest for knowledge, not complaining!!!!

I think you are mistaking what exactly that checker is outputting. It is, in the "Line speed capabilities", giving nothing more than the BT checker, an estimate of what you line might achieve. This is not saying your line rate is SET at anything, and shouldn't be taken that way.

Adam

[bobleslie]

I'm in exactly the same position as you, with the same exchange checker results.

Always maximum up/down sync rates but with the line apparently 'maxed' at 6500.

I don't normally exceed 5500 - 6000 even in the early hours of the morning.

I assumed that this would eventually rise as BT got its act together and/or the exchange installed more capacity.

=Bob=.

[pazzaTgreat]

I think you are mistaking what exactly that checker is outputting. It is, in the "Line speed capabilities", giving nothing more than the BT checker, an estimate of what you line might achieve. This is not saying your line rate is SET at anything, and shouldn't be taken that way.

Adam

Are you certain this is only a guesstimator Adam?

This seems coincidental that this factor really is my max rate, despite the *apparently* better looking stats.  This rate is also the improvement over the 2Mbit cap that we saw in the early adopters after 3 days and never got any better. 

It looks like a very detailed report which does apparently explain my situation.  However, many people have come up with theories to fit the facts and have still been wrong.  I may well be one of them, rare though that occurrnce is    

[Adam]

Are you certain this is only a guesstimator Adam?

While I can never be 100% without knowledge of what it exactly does I'm 99.99% certain it is, here is my reasoning why;

-I have checked a few lines, and all returns the same "estimate" as the BT checker, only difference being that checker neatly displays it as going up, whereas the BT checker just uses "up to".

-That checker gives me a rate of 4000Kbps, I sync at around 5000kbps, and receive speeds a fair amount above 4000Kbps at around 3am.

-They would not, to my knowledge, have access to such information about your connection.

Adam

[pazzaTgreat]

Are you certain this is only a guesstimator Adam?

While I can never be 100% without knowledge of what it exactly does I'm 99.99% certain it is, here is my reasoning why;

-I have checked a few lines, and all returns the same "estimate" as the BT checker, only difference being that checker neatly displays it as going up, whereas the BT checker just uses "up to".

-That checker gives me a rate of 4000Kbps, I sync at around 5000kbps, and receive speeds a fair amount above 4000Kbps at around 3am.

-They would not, to my knowledge, have access to such information about your connection.

Adam

BT's own checker tells me I sould get 6.5 up to 8 but this has not been the case.
Average throughput is in the range 4-6Mbits. 

If the checker can have full access to DSLAM stats, why not be able to report line speeds too? 
If legacy BRAS profiles are set on a line, would an ISP not be able to access them from a BT resource?
addition
Plus - if as Bill suggested earlier the best we will really see is around 6.5ish, Max is being incorrectly sold as no-one appears to be getting "up to 8Meg", except in the real sense that all our speeds are below that 

I wold like an investigation by Ofcom into the realities of "up to 8Meg" from this product, although I applaud it for improveing many longer reach customers.  I would still have bought into a 6 meg product if that is what it really was but I perpetually get the feeling that BT misled everyone about the capabilities of the product. 

How could they fail to anticipate that a large number of people moving up to the 8 meg product wouldn't have routers for example?  That early phase was a farce and I wonder if I am still suffering from the fallout. 

Who governs what BT provide as an acceptable service?  a minimum rate of 400kbps an an up to 8 meg line doesn't meet my standards.  Does it meet anybody elses?  When do you find this out? Only after you sign up.

[Bill]

Ah - but the point I'm making isn't about the actual speed Bill, it's about the line rate set at the exchange - I have the same stats ish as you but you are getting better throughput but this checker has shown my line to only support 6500.  This has never been intimated before, and if I sync at 8128 why is my line rate 6500?  I am on a quest for knowledge, not complaining!!!!

If you do this check, with the same stats - what does it show your line rate as?

Like Adam said, it's an estimate. I posted a query about it in the AG General BB Chatter forum here, and got the same answer- it's an estimate.

For my exchange I get:

Line speed capabilities

Rate adaptive (250k and 500k) :    Green   
Fixed Rate (1000k and 2000k) :    Green   
MAX speed (upto 8000k) :    Green (6000 kbps)   

250k, 500k, 1000k, 2000k and 6000k are all available on this line.

Considering I'm just over 1Km from my exchange, the figures match with yours.

[pazzaTgreat]

Aaargh Damn !!!

I was REALLY hoping this was an explanation and for the less than max performance but hey ...

Thank you all for your input and at least I've learned something. 

On that note then, is anyone seeing better than 6.5ish on this product?

Addendum - here is an updated link form the place I gleaned most of my early knowledge from.  I should have checked it again before tirading about BT (hang head in shame) but in my defence bog standard ADSL does allow for 8Mbit up to 2km or so from the exchange. 
This now has a very good looking explanation of Max DSL.  It also, however, does suggest as I still believe, that a data rate is set and this could be less than the rate the line is really capable of.

http://www.kitz.co.uk/adsl/maxdsl2.htm

[Adam]

I should have checked it again before tirading about BT (hang head in shame) but in my defence bog standard ADSL does allow for 8Mbit up to 2km or so from the exchange.

That's assuming all is perfect, needless to say, the BT network is far from perfect.

All fairness to BT though, it's sold as an "up to" product, any misleading would be the fault of the ISP.

Would *I* be happy with 400Kbps speeds on an "up to" 8mb line? No, but they still sell fixed rate products that I can go back to, and have somewhat guaranteed speed.

Adam

[pazzaTgreat]

That's assuming all is perfect, needless to say, the BT network is far from perfect.

All fairness to BT though, it's sold as an "up to" product, any misleading would be the fault of the ISP.

Would *I* be happy with 400Kbps speeds on an "up to" 8mb line? No, but they still sell fixed rate products that I can go back to, and have somewhat guaranteed speed.

Adam

Never denied it was an "up to" service - the parameters need clearer definition in my opinion since the reality is "up to"  definitely only 7.15Mbit, therefore the statement "up to 8Meg" falls into the same category as "unlimited  - _{fair usage of 1GB per month applies}" as recently gotten away with by Vodafone.     

I am pleased with the overall performance improvement, but as I said earlier, I am really on a quest for knowledge as to what constitutes good line, top speed capabilities etc. and thus the *discovery* which *proved my point* seemed appealing but I have to doff my cap to your corrections  and accept that this is not the case.  So I am no nearer to finding concrete answers that can either satisfy myself or be of sufficent depth to pass on to others

My tirade is really directed at the lack of information provided by BT.  I phoned them as I said earlier and to say they were a little obtuse would be flattering.  IDNet have been more helpful and useful than any other ISP I've been with.

On another note - Bill's post about BT's lockdown might be something which comes into play here too.

Cheers for the extended discussion, and enjoy the Karma points

Paul 

[Coopes]

mine this morning at 8:25


Rate adaptive (250k and 500k) :  Green
Fixed Rate (1000k and 2000k) :  Amber
MAX speed (upto 8000k) :  Green (3500 kbps)

250k, 500k and 1000k ADSL is available on this line. 2000k ADSL is not likely to be available on this line.250k, 500k, 1000k, 2000k and 3500k are all available on this line.

Mark - does the indicated 3500kbps match what you see as throughput??

No mate nowhere near about 1mb+ lesss sometimes on throughput

[mrapoc]

i dont actually think its possible to get up to 8mbps unless u live in the actual exchange 

[pazzaTgreat]

i dont actually think its possible to get up to 8mbps unless u live in the actual exchange 

It isn't possible to get 8 meg on MAX at all 

I for one am dying to have LLU happen in my area because the faster we get off BT Ipstream, the quicker OFCOM will let BT deliver fibre based networks to become competitive again 

Then MAX will become a distant memory to tell my grandchildren -

"When I were a lad, we 'ad it tough.  Listen up little un's, because once upon a time we got poor, variable speed service on an overloaded infrastructure which meant we had to wait oooh anything up to 5 minutes to download a questionable video clip in dreadful pixellated messiness.  None of your massive resolution video delivered on a highly reliable standard speed network in seconds you know ...."