Where on Kitz did you get the figures quote and wording looks very like my site?

Kitz for 26dB says a 17600 sync speed? No playing around with noise margin. At least where I can easily spot

I'm not sure what you are asking.

I got Kitz's estimate for my attn. from: http://www.kitz.co.uk/adsl/max_speed_calc.php and fed them into your calculator which produced the figures I quoted. I am querying those figures.

Kitz assumes as standard:

The calculator is based on a default Target SNR of 6dB.

Kitz does not exactly commit to how much speed increment is due to a 3dB delta in NM other than:

Each 3dB of SNR is worth anywhere between 400 to 1200kbps of speed

but no-one else has ever suggested a fantastic 5 Meg change per 3dB delta in NM.

You calculator and Kitz's fulfil 2 diff functions.

Kitz simply estimates the speed at a given attn. for a standard 6 dB NM.

Yours takes in all 3 stats and 1) rates the current speed on a traffic light basis, 2) simply restates the current speed if the NM falls on a 3dB step and 3) estimates the speed at other 3dB NM steps.

It is the results of the function 3) that I am querying as I find them most suspect.

You said "I put in the Kitz figures, which I understand is meant also to cater for mid-range expectations, for my 26 dB attn. line: 17600 K, 26dB attn., 6dB NM and get the results" and then pasted a set of data that looked like it was from my site, so was worried someone had lifted my code.

So much code I have written in the last few weeks I cannot recall the exact logic and algorithm of everything a the snap of my fingers.

So what is the right speed for a line of 26dB attenuation at 3dB?

The only accurate way to do the calculation would be data from every frequency bin, and even then with noise variability you would be wrong at different times. The calculator is not a total replacement for someone casting an eye over the stats and asking questions - it is also not stated to be 100% accurate.

I get a mixture of too slow emails and too fast emails, which normally suggests about right.

Sorry, perhaps I wasn't as clear as I could have been.

In the context of discussing your calculator, I just meant I put in Kitz-derived figures into it.

OK!

No one expects an absolutely accurate estimate; it is an estimate after all, but nor do they expect widely variables ones.

I do wonder what proportion of your emails relate to the current speed at the presently imposed Target NM and how many to the potential speed at other possible Targets. I wager it is more natural to be biased towards the former.

However, it is the latter I am doubtful about and if they are not reasonable estimates then it brings into question as to their worth.

Edited by XRaySpeX (Thu 21-Feb-13 00:26:15)

My stats of the ADSL has seem to have changed again. Here's the latest stats again below. And you said my sync speed should be around 17meg, how will I go about fixing that?


ADSL

Type Interleave Path
Status Show Time

Downstream Upstream
Data Rate (kbps) 13253 448
Noise Margin (dB) 3.5 33.1
Attenuation (dB) 27.3 13.9
Output power(dbm) 20.4 12.5

In reply to a post by MrSaffron:

I guess its AOL LLU due to the slow upstream.

How does that follow (from a 448K quasi-ADSL Max Up Sync)?

Just had a look at the AOL Forum, LLU exhibits this sort of normal ADSL2+ Up Sync:

In reference to forums.thinkbroadband.com/aol/t/4196222-re-me-or-them.html:

Data Rate (kbps) 12403 1020

Not the the use of the word GUESS, implying not a fact but a hunch.

Given AOL uses TalkTalk LLU and thus available on 94% of lines, would not expect them to use WBC which has a smaller footprint