Help with stats and speed.... Please

I've just been connected to Sky and my speed seems pretty low to that which I was quoted, I know a lot can change within the first 10 days, so I am not worried at this stage.

After looking at my stats, the Noise Margin seems high at 15.3 when Sky usually goes down to 6db, so a lot to play with. At my previous address, using the 7800n router I managed to get a stable connection with the Noise Margin down to 3 db.

I've listed my current line stats below, could someone give me a good estimate of the speeds I should be achieving with those stats. The stats seem good to me but I may be wrong;

Broadband Link Downstream Upstream
Connection Speed 4091 kbps 606 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 15.3 dB 19.19 dB

Many thanks in advance...

Currently using the Sky hub, I'll be switching to the Billion 7800n with the SNR tweaks once I obtain my Username and Password from the hub.

Is there a different program to that which was used with the Sagem to get your User details or can you use the same?

Thanks again

Those stats remind me of what one might see with a Sky ADSL MAX "Connect" account except for the upstream sync of course.

Give it time and it might improve: a downstream SNRM of 6dB on an ADSL2+ attenuation of 23dB should give you a downstream sync of 19168Kbps.

Was the router connected to the test socket with all phone extensions disconnected when you recorded those stats?

The router was connected directly to the master socket, not test socket. I have no extensions in the property, just the one line coming in and the main socket.

The service was only activated today, so I'm not surprised that the speeds are low but I thought those stats were pretty good and should give me a lot better sync than that what it is at the moment.

Am I missing something? You say those stats remind you of an ADSL MAX 'Commect' account...

So, would you say the stats are pretty poor?

Thanks for your help....

Can you try connecting the router to the test socket behind the master NTE5 faceplate via a dangle micro filter without a cordless phone connected or powered on, if that is your setup?

Also try a corded phone, if you have one, in the test socket with and without the router connected and check for any audible noise?

Sky ADSL MAX "Connect" doesn't have a good reputation for BB performance - but I'm fairly certain that you don't have that since your upstream sync is well above 448Kbps

It's defiantly Sky Unlimited LLU or that's what's ordered and shows on my statement. Usually the target SNR is 8 with Sky, possibly 6. Seems odd that its up around 15 :/

I'll try and get to the test socket but some fool has two central heating pipes in fromt of it which makes it difficult to get access...

DONT PANIC

Sky start of their DLM at 4 Meg and increase the speed over a period of days to what they think is the fastest speed the line can handle

Ah brilliant. So in theory, with those stats I should or could achieve 16Mb?

Thanks

In reply to a post by shaneosborne:

I'll try and get to the test socket but some fool has two central heating pipes in fromt of it which makes it difficult to get access...

Please ignore what I said about connecting to the test socket etc. I didn't realize, as Mr Saffron pointed out, that your speed will start at a meagre 4 Meg

Thanks 4M2, I wasn't aware Aky started at 4Mb. I'm sure other providers start from the top end of the scale and lower accordingly dependant on errors etc.

In reply to a post by shaneosborne:

Thanks 4M2, I wasn't aware Aky started at 4Mb. I'm sure other providers start from the top end of the scale and lower accordingly dependant on errors etc.

That's the great thing about this web site - we learn so much useful info

Just like you, I would certainly have been very concerned if I only got 4 Meg for starters...

If my Sky line can sync at 7.8 Meg at 42 db then in time yes

MrSaffron, as nearly () always, is correct. Sky connect initially at 4Mbps then up it over a few days.

In reply to a post by shaneosborne:

Ah brilliant. So in theory, with those stats I should or could achieve 16Mb?

Thanks

I think Sky still do a 7dB sync-time margin. Say 18dB sync, 84% of that real maximum throughput.

In reply to a post by shaneosborne:

Broadband Link Downstream Upstream
Connection Speed 4091 kbps 606 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 15.3 dB 19.19 dB

Today's Stats (Sun 14th April 2013);



Broadband Link Downstream Upstream
Connection Speed 7002 kbps 796 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 14.4 dB 15.15 dB

So, whilst the sync speed is now higher the NM has dropped (as expected) but not by a huge amount. I'm hoping that I will get as close to the max speed or anything above or around 16Mb, I don't really want to switch to Fibre as yet, the given speeds via the checker ain't that great to justify an extra £15 pm..... Some may say a max of 38Mb is worth the extra spend. I would have thought I would have been quoted better than a max of 38Mb on both Infinity 1 and 2 not unless the checker is well off what your line can achieve.....

Those stats are really interesting

It's the upstream SNRM that has changed the most and yet with little change to downstream SNRM you have gained nearly 3000Kbps...

Things are certainly moving in the right direction!

Edited by 4M2 (Sun 14-Apr-13 18:57:50)

With Sky the speed increases in steps, and their power management means that you cannot use the usual estimate and SNR margin rules.

In reply to a post by MrSaffron:

With Sky the speed increases in steps, and their power management means that you cannot use the usual estimate and SNR margin rules.

Could the OP expect 19000Kbps (or 16Mbps which seems to be his benchmark) within the first 30 days? I guess the increase of 3000Kbps seen over the first 3 days would achieve that...

Edited by 4M2 (Sun 14-Apr-13 20:05:33)

Well, I was activated at 6pm Friday so I'm on Day 3 as of now.

What do you mean when you say 'their power management means that you cannot use the usual estimate and SNR margin rules'. What differs and do any estimates differ widely compared to the usual estimates?

Sky have estimated my line to achieve anywhere between 12Mb and 19Mb.

Edited by shaneosborne (Sun 14-Apr-13 20:10:19)

Have you got that broadband and line rental deal free for the first 6 months, excluding line rental, then £10 per month for the remaining 6 months = £5 per month for broadband and line rental at £14.50 a month, also the "30 day Broadband and Talk Satisfaction Guarantee"?

I have just the Free Broadband for 6months then it reverts to £7.50. I ordered via Quidco so also received £150 Cashback plus £100 M&S Voucher.

Doesn't the Satisfaction Gaurantee cover all new customers?

In reply to a post by shaneosborne:

I have just the Free Broadband for 6months then it reverts to £7.50. I ordered via Quidco so also received £150 Cashback plus £100 M&S Voucher.

Doesn't the Satisfaction Gaurantee cover all new customers?

That's a really good deal

I was just looking at the Sky web site and it did mention the satisfaction guarantee and I just wondered if you ordered the package from there and were aware of it...

I wasn't aware of the Gaurantee until you mentioned it, I'll have a read of it shortly. Thanks

Should be OK

But it's good to keep your options open for the first 30 days just in case the BB performance doesn't meet your expectations.

Edit: I had a satisfaction guarantee several years ago with o2 ADSL MAX and I'm really glad that I did because the service was rubbish - in all likelihood your Sky ADSL2+ performance will more than meet your expectations though

Edited by 4M2 (Sun 14-Apr-13 21:11:23)

Probably rise to around 16 Meg, and with some pestering they might be able to get the profile tweaked when phoning them up.

The Sky range is still achievable.

I was trying to say that with Sky you cannot use the usual charts people have in their heads for speeds when they look at the noise margin. Sky has a tendency to be 5-10% slower than the other providers due to a preference for stability over absolute raw speed.

Like a dependable car that goes up and down the motorways no problem, compared to a highly tuned one, that stutters some weeks

Once its stabilised ill use my Billion 7800n and use the SNR Tweaks and then get Sky to up the profile as Zi did at my previous address

What I don't understand is that I am likely to get near max speed on ADSL where the exchange is a lot further away, yet Fibre only gives me 38Mb and the cab is a lot closer (I think). Shouldn't I get better than 38Mb on Fibre? Confused

Where are you getting a fibre estimate of 38Mbps from?

Edited by RobertoS (Sun 14-Apr-13 23:12:45)

Maybe OP got them from here http://www.thinkbroadband.com/guide/fibre-broadband.... - a cabinet to premises distance of 500m = ~38Mbps or the BT 40GB usage deal where 38Mbps downstream speed is quoted possibly in average terms on the same page?

BT Infinity Page, it gives me the same for both Infinity Option 1 and Option 2 :/

When going through the order process it checks your line and gives you the estimated max line speed, it says option 2 is upto 74mb (or whatever it is) both says my line can only achieve a max of 38Mb once it checks the line.

The upload was better on option 2 but download was the same as option 1....

Speed increase again today but it doesn't look like I'll be getting 16Mb, the NM has certainly closed a lot even with just a Mn increase in upstream sync;



Broadband Link Downstream Upstream
Connection Speed 10237 kbps. 1117 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 8.6 dB. 8.8 dB

Give it time, as Mr Saffron said, "with Sky the speed increases in steps, and their power management means that you cannot use the usual estimate and SNR margin rules."

It's possible you may get a downstream 16000Kbps sync with a 9dB SNRM for stability or a bit faster at 18000Kbps with 7dB SNRM as I believe RobertoS suggested in due course

Thought I would post today's line/connection stats, we are below the 7db target for Sky but read elsewhere that Sky can go as low as 3db since an update last year.

The only time I've got it around 2.5 - 3db was using the SNR Tweak on the Billion 7800n, in fact I managed to get it to 0.8db and was still stable but I was next door to the exchange at my previous address....



Broadband Link Downstream Upstream
Connection Speed 13307 kbps 1110 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 6.0 dB 8.8 dB

Edited by shaneosborne (Tue 16-Apr-13 16:14:17)

Looking good - more than 3000Kbps increase in downstream sync speed and SNRM down to 6dB, another 3000Kbps and you will reach your benchmark 16Mbps

Thanks for posting the stats: it's really interesting to see how your connection is being adjusted for optimal performance.

I thought it would be good to post the daily stats to show others how Sky operate the 10-day line testing phase.

I know it was something which I was looking for on these forums prior to posting.

The adjustment seems to take place once the line is quiet with no activity, once everyone has gone to bed and shutdown the puters, within an hour the new rate takes affect. In our case its between 0200 and 0300 once daily......

I'll post more stats on a daily basis, hopefully others will find it interesting to see how its working...

Yes, hopefully others will find it both interesting and informative.

I went onto partial LLU (uno TTB) more than a year ago - from "the word go" I was on a 6dB downstream SNRM, ~13500Kbps sync interleaved with a 37dB attenuation and it has stayed solidly like that ever since. It seems the Sky LLU kit has a much more gradual way of doing things

Normally, looking at my last set of stats I wouldn't expect anymore from Sky. In fact, I would expect a little less while they get the SNR back to 7db but as MrS says, Sky work differently to other providers...

I'm interested to see how much more I can achieve without tweaking the SNR...

All we can do is wait

With the speed capping used by Sky, doing things like tweaking SNR margin locally usually has no effect

The way I got it to work was to tweak it and then telephone them saying that it looks like I have a lot more SNR available and then they would adjust. It seems that when its tweaked my end it they see that there is still enough available and adjust accordingly.

Then once they adjust the profile the tweaks take affect

Edited by shaneosborne (Tue 16-Apr-13 18:20:13)

In reply to a post by shaneosborne:

Broadband Link Downstream Upstream
Connection Speed 13307 kbps 1110 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 6.0 dB 8.8 dB

Here are today's



Broadband Link Downstream Upstream
Connection Speed 16378 kbps 1117 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 6.5 dB 9.9 dB

In reply to a post by shaneosborne:

DAY 01 & 02
Broadband Link Downstream Upstream
Connection Speed 4091 kbps 606 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 15.3 dB 19.19 dB

DAY 03
Broadband Link Downstream Upstream
Connection Speed 7002 kbps 796 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 14.4 dB 15.15 dB

DAY 04
Broadband Link Downstream Upstream
Connection Speed 10237 kbps 1117 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 8.6 dB 8.8 dB

DAY 05
Broadband Link Downstream Upstream
Connection Speed 13307 kbps 1110 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 6.0 dB 8.8 dB

DAY 06
Broadband Link Downstream Upstream
Connection Speed 16378 kbps 1117 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 6.5 dB 9.9 dB

I'm a little confused and hope someone can ease my confusion.
As you can see by my daily line stats above, my speed as been increasing daily whilst Sky begin working out the best stable speed my line can support.

What's confused me is that I thought as your speed/sync increases it creates more noise which in turn lowers the noise margin, as you can see by the stats this isn't the case. I always thought the faster the line, the more noise it creates. I'm obviously wrong, can someone explain please?

As I believe I said, the way Sky manage the power levels mean that the noise margin does not follow the normal rules.

By reducing the amount of power (i.e. electricity) used they can reduce power consumption in exchange hardware, so run it cooler, save power and maybe reduce cross talk issues a little.

BTW increasing line speed does not create more noise as such, but because you are using more parts of the frequency allocation, there is less margin available between the level of noise present and the transmitted or received signal as.

Ah right! I was aware if what you said but didn't know how it worked differently to others.

So when working out the speed they also adjust the power at the same time when others don't thus when the line reaches a low NM they up the power along with the sync?

Thanks for explaining...

It does seem like a power, noise and margin balancing act: start off on largish sync time margin with reduced power; increase the power and monitor any significant reductions in margin; lower the sync time margin, again with reduced power, then increase the power, and so on...and I guess, each time this will increase sync speeds accordingly until a point of specified potential instability is detected on a particular line?

If that is a simplified view of the system it looks pretty good to me, however, perhaps one has to be patient for the first few days or so

That's how I understood it... Looks good so far, lets hope they can throw a little more power down my line without it causing problems

http://www.coolwebhome.co.uk/calc/calculator.php?par...

Estimates based on latest stats, the key one is the attenuation based estimate which says
"Normal speed range at 23dB attenuation is 17400 Kbps to 19000 Kbps"

So seems scope for a bit more, whether Sky deliver is another matter.

In reply to a post by shaneosborne:

That's how I understood it... Looks good so far, lets hope they can throw a little more power down my line without it causing problems

Hopefully yes, since with a downstream 6dB SNRM a 19Mbps sync speed should be possible on your line - a 3dB margin would probably give you even faster speed but it might be unstable...

Guess you will probably switch to the Billion router once the connection has stabilised at or above your benchmark 16Mbps sync?

I'll switch to the Billion after the 10days, tweak and then plug in my Samknows monitoring router and hopefully all will be fine for then on...

In reply to a post by MrSaffron:

As I believe I said, the way Sky manage the power levels mean that the noise margin does not follow the normal rules.

By reducing the amount of power (i.e. electricity) used they can reduce power consumption in exchange hardware, so run it cooler, save power and maybe reduce cross talk issues a little.

This in fact sounds like "DSM Level 2", the next step up from plain DLM.

The aim is to set the power level on many lines in a way that allows them to co-operate in causing the least amount of noise to each other.

It could be that, while the power level of *this* line is being adjusted upwards, the power level of other lines is being adjusted downwards slightly.

DSM Level 2 is meant to work on frequencies too, adjusting the way in which power is used over different frequencies. It could be that the bits/tone graphs have been altering too.

Well, a little more extra today. now at 18Mbps / 1.2Mbps

Connection Stats;



Broadband Link Downstream Upstream
Connection Speed 17961 kbps 1189 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 6.1 dB 9.9 dB

In reply to a post by shaneosborne:

Connection Stats;

Broadband Link Downstream Upstream
Connection Speed 17961 kbps 1189 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 6.1 dB 9.9 dB

Well, I think we've reached the end. Sync has stabilised and last night it seems the power was lowered by looking at the NM.



Broadband Link Downstream Upstream
Connection Speed 18008 kbps 1179 kbps
Line Attenuation 23.0 dB 13.6 dB
Noise Margin 3.9 dB 8.8 dB