IDNetters Forums

Technical News & Discussion => IDNet Help => Topic started by: kinmel on Nov 15, 2010, 15:32:03

Title: Change in target margin?
Post by: kinmel on Nov 15, 2010, 15:32:03
Whilst until this week I would agree with all that, apparently it is no longer necessarily true.

A month ago my broadband connection, together with 5 neighbour's lines went beserk with the SNR varying between 4 and 23 together with constant disconnects.  My sync rate over 3 weeks varied between 624 and 4000.

Eventually everyone's phonelines have settled down and my 5 neighbours are back to normal.

My line suddenly started to sync at 9 and nothing else and then 12 and finally 15.

Every re-sync at any time of day, with any router is to 15, even if moments earlier the SNR was higher.  What are the chances of line conditions matching 15 at precisely that moment every single time.

Support are adamant that my SNR is not targeted at 15, but since line noise is random and constantly changing, I cannot believe that the resync only ever occurs at 15 dB.  It is beyond the realms of probability.


But if Support are correct, then our understanding  of SNR/Sync is fundamentally wrong



Title: Change in target margin?
Post by: Rik on Nov 15, 2010, 15:57:47
Very odd, Alan. Could you run Routerstats for a while and see what changes there are to the NM?
Title: Change in target margin?
Post by: kinmel on Nov 15, 2010, 16:39:26
Quote from: Rik on Nov 15, 2010, 15:57:47
Very odd, Alan. Could you run Routerstats for a while and see what changes there are to the NM?

Routerstats has been running 24/7 for months with the SNR and Sync graphs saved and passed to support.

The SNR moves up 1 or 2 above 15 at times.  Re-syncs are very rare.

Today, steady at 16, force a re-sync and it goes to 15, not the 16 it had 2 seconds earlier !

(http://a_woodward.www.idnet.com/NoiseMargin-2010Nov15-0810.jpg)

and the sync rate goes up at the same moment

(http://a_woodward.www.idnet.com/sync%20today.jpg)

it was 4000 a few weeks ago  even though support insist that a 57 attenuation can't reach that

(http://a_woodward.www.idnet.com/ConnectionSpeed-2010Oct08-0249.jpg)
Title: Change in target margin?
Post by: Rik on Nov 15, 2010, 16:40:55
That does look like a target NM to me.  :shake:
Title: Change in target margin?
Post by: kinmel on Nov 15, 2010, 16:57:30
Quote from: Rik on Nov 15, 2010, 16:40:55
That does look like a target NM to me.  :shake:

Well if it is not a Target Margin, then either the Laws of Probability, or the science has changed.

The BT Engineer who came here claimed he could not diagnose the problem whilst the margin was fixed at 15.

When I originally asked for the target to be changed I was actually told by Support that my router is "remembering" the previous value - except I have tested using 5 BNIB spare 2700 routers/power supplies/filters/cables - all lock at 15.

The final story is that the line is not targeted in any way and line conditions are such that the router(s) always syncs at exactly 15; no-one tries to explain the move from 6, to 9, to 12 and then to the current 15.

It appears that Idnet cannot get BT to do anything at all to improve the line
Title: Change in target margin?
Post by: Rik on Nov 15, 2010, 17:09:48
It's my understanding that support have done all they can to get BT to improve the line, Alan, but that BT aren't prepared to do more. Even though they have reset your margin a number of times, it keeps resetting to 15, but there may have been a misunderstanding in the way this was communicated to you. If you have an LLU option, you might be able to improve things, at least by getting rid of profiles, but the 'last mile' is still Openreach, so you won't be entirely free of the problem.
Title: Change in target margin?
Post by: kinmel on Nov 15, 2010, 17:28:25

Everyone else in this area, whether with BT or LLU, get at least 1.5 meg higher than my current 2496, as I did too until a few weeks ago.

BT are happy to leave the line in it's present state and I am currently looking at options.

I intend to have a new phone line installed whilst the current line is still in use, that will stop them using the existing useless pair on the new line.  The old line will then be ditched.

It is all about finding the best way to do it, if I stay with Idnet I will pay £110 for the line install, but do I also have to pay an initial broadband connection fee when Idnet transfer the service from one line to the other ?

Sky LLu offer a new line for £39 and no initial broadband connection fee.
Title: Change in target margin?
Post by: Rik on Nov 15, 2010, 17:33:24
Yes, it's a new physical connection, so there would be the £47 connection charge, Alan, sorry. :(

Fwiw, from a group of five houses at this end of the Close, I have 3.5Mb, next door has 512k, over the road has 1Mb, and the two at the bottom of the Close get 1.5Mb. I've done all the usual things to help their speeds but to no avail. I was an early adopter, and that seems to have paid off with a friendly BT engineer, in the days before Openreach, finding the best pair for me. That doesn't tend to happen anymore.
Title: Change in target margin?
Post by: kinmel on Nov 15, 2010, 18:04:50

I emailed Support over the weekend for some information so  I will wait until they reply before deciding, but somehow £157 doesn't compare favourably with £39
Title: Change in target margin?
Post by: Rik on Nov 15, 2010, 18:05:14
Understood.
Title: Change in target margin?
Post by: Steve on Nov 15, 2010, 18:24:57
Certainly Sky would be a lot cheaper for me,their LLU is available on my exchange, my assumption is that my adslmax connection with IDNet will probably out perform SKY's LLU I maybe wrong though. My Fibre date has now gone back to 09/11
Title: Re: Change in target margin?
Post by: Rik on Nov 15, 2010, 18:57:56
NOTE: This thread split from original, hence Alan's reference to comments in that thread:

http://www.idnetters.co.uk/forums/index.php?topic=23220.msg554598#msg554598
Title: Re: Change in target margin?
Post by: Glenn on Nov 15, 2010, 19:00:49
Quote from: Steve on Nov 15, 2010, 18:24:57
My Fibre date has now gone back to 09/11

Mine now says 31/12/10, 3 months earlier than before, according to Samknows.
Title: Re: Change in target margin?
Post by: Colin Burns on Nov 15, 2010, 19:23:41
i had this issue quite some time ago and got support to reset the noise margin which resulted in a complete waste of time as BTs evil software just booted the noise margin back to 15...  in the end it took several weeks of leaving the router alone and it eventually crawled back to what is was
Title: Re: Change in target margin?
Post by: kinmel on Nov 16, 2010, 10:13:07
Quote from: kinmel on Nov 15, 2010, 18:04:50
I emailed Support over the weekend for some information so  I will wait until they reply before deciding, but somehow £157 doesn't compare favourably with £39

Someone is taking the p*ss

I emailed Support yesterday regarding a new phone line to replace my current poorly performing one.

After answering my queries the following punch line was unnecessarily added to their reply ......

"The connection on the current line appears to be working correctly and seems to be stable.".  For a line that supported 4meg until recently and can now barely reach 2500 !

That one sentence has annoyed me enough that no matter what, Idnet have no part in my future broadband plans.





Title: Re: Change in target margin?
Post by: Simon on Nov 16, 2010, 10:38:15
Sorry to hear that, Alan. 
Title: Re: Change in target margin?
Post by: Rik on Nov 16, 2010, 10:43:30
That's BT speaking, through IDNet, Alan. BT won't acknowledge a fault on your stats, so if the service is stable, there's nothing iDNet can do. One of my lines gets 3.5M, the other 2.5M, BT are adamant that both lines are fine.  :shake:
Title: Re: Change in target margin?
Post by: Steve on Nov 16, 2010, 10:48:23
I guess Sky LLU may allow some flexibility on the noise margin as your probably prepared to put up with the odd bit of instability if throughput is higher. 
Title: Re: Change in target margin?
Post by: kinmel on Nov 16, 2010, 10:54:53
Quote from: Rik on Nov 16, 2010, 10:43:30
That's BT speaking, through IDNet, Alan.

Idnet Support are fully aware that I am prepared to ditch the line and that comment added nothing to the debate, it was merely repeating BT's mantra yet again.

I have asked AAISP if their Broadband We'll fix your line (http://www.aaisp.net.uk/broadband-trial.html) scheme is suitable, if not it will be a new line on Sky LLU
Title: Re: Change in target margin?
Post by: Rik on Nov 16, 2010, 10:58:04
Keep us posted.
Title: Re: Change in target margin?
Post by: kinmel on Dec 10, 2010, 16:38:13
It is a week now since my 10 day training period ended after the migration to AAISP.

The same line, with everything at my end unaltered, has been sync'd at 4129/992 at about 6dB since 27th November.

I have now regained the old 3.5meg profile that I had for many years, a 75% improvement on the throughput I had during my final month with IDNet.

Title: Re: Change in target margin?
Post by: Rik on Dec 10, 2010, 16:45:58
Thanks for letting us know, Alan. You may have noticed that, with effect from Monday, ISPs will have even less control over line testing. :(