Kitz Forum

Broadband Related => ADSL Issues => Topic started by: MikeS on January 04, 2008, 12:57:48 PM

Title: Very high noise margin drop in afternoon
Post by: MikeS on January 04, 2008, 12:57:48 PM
Hi

I've been experiencing random connection drops and the associated IP profile hammering for a long period of time.  Despite changing computers/modem/router and 4 visits from BT the issue still exists.  I was recently told about routerstats and I've been using that over the last two weeks.  A pattern has emerged which is as follows - switch the computer on in the morning syncs at 2300 ish and 15 dB noise margin, this holds fairly steady within about 2 dB until 3.00pm ish when the noise margin starts to fluctuate quite significantly while all the time trending down, until by about 10.00 pm I'm around 0 to -2 dB.  Have attached a trace of a typical day (in fact a good day as I didn't lose sync).  I have been told that a typical 'evening drop' is 3-4 dB, whereas I'm seeing 10-15dB routinely.  If it's a bad day and I drop synch at below -2dB it resyncs to a 15 dB noise margin and my sync speed and IP profile go down, and on a really bad day it can go down severely from 2000 to 250, which I am then stuck with for a couple of days. 

I am currently using a faceplate splitter with the router plugged directly into it.  My line attenuation is 52 dB. Each of the BT visits resulted in them finding a fault and fixing it but the underlying issue has not changed.  I live in a residential area, no street lights.  All the electrical stuff in the house is on in the morning as well as the afternoon. 

Would aprreciate any thoughts either in respect of how to approach this with BT or the underlying cause.

Thanks
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 05, 2008, 05:45:16 PM
Hi MikeS (my first post here, but I've been lurking for ages!),

I had similar problems to you. My attenuation is 50db.
You haven't said which routers your tried. I went from a Netgear > 2Wire > Thomson Speedtouch.
The Speedtouch sorted all my problems!

I've documented my story here: http://www.hmmm.ip3.co.uk/adsl-snr/index.shtml
You'll see I'm also a fan of RouterStats which I used to monitor the routers.

Let us know which routers you have tried.
Hope this helps.
Hmmm...
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 05, 2008, 05:55:14 PM


Currently using an SAR600-EH which is the most stable in terms of holding on to sync (down to about -4dB) I have used.  Borrowed a Netgear and a Belkin, can't remember the models, about 6 months back but they dropped sync a little easier and showed the same deterioration of noise margin as the evening progressed. 
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 05, 2008, 07:59:33 PM
Hi

That certainly shows very clearly that something is causing interference with your adsl signal.  Although finding what that is, is often the hard part :/
Is your property attached?  Is there anything in a neighbours house that could be causing this?

That graph could be very helpful to an adsl engineer as it shows that there is a problem, and BT do have diagnostic kit which may be able to help pick up where any additional noise is coming from.  Obviously you would need to request via your ISP that an engineers visit late in the day would be most beneficial since that is when your SNR starts to drop.

One thing I do notice is rather than a steepish drop within a short time frame you would normally expect to see if its something being switched on.. yours appears to "build up" over a much longer time frame.
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 05, 2008, 09:14:19 PM
Hi Kitz

We are in a detached house about 60 m or so from our neighbours.  I'm not aware of anything at our neighbours which could be responsible, they just have the usual domestic electric items, which are on in the morning as well as the afternoon. The slowish decline in noise margin is typical, as are the +/- 5-7 dB peaks and troughs during the decline.  As I write I'm on -2dB (but still in sync) - small mercies.  About 200 yds up the road there is a Vodaphone mast but why should that impact post 3 pm only.  I'm with Plusnet and they have been helpful in trying to get to the root of the problem.  They have rejected BT's last problem fixed report, so I'm hoping for another engineer visit.  I have asked them to explain the issue of noise margin so hopefully I will get an engineer who is up to speed.
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 06, 2008, 09:57:29 AM
Looking at your SNRM graph it looks similar to mine (and lots of others) - i.e. as darkness arrives the margin starts to drop until things become unstable.

I wasn't familiar with the "sar600e" but if my search was correct this is a Solwise router using the Texas Instruments AR7 chipset - as most older Netgears also do. It seems some line conditions/DSLAMs can have noise issues when your router uses this chipset.  Moving away from the AR7 chipset resolved my problems!

The 2Wire 2700 performed better but the Speedtouch 585v6 sorted things!

My suggestion would be to try to borrow a Speedtouch or buy a new one from eBay as I did (around £30)...

Good luck.
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 06, 2008, 10:25:11 AM
Hi b4dger

You are correct about the router, as far as I am aware it is a 600E with a built in homeplug.  The homeplug network which I use appeared to have no effect on the noise margin issue, although in practice because I can plug my router directly into the master socket rather than going through extention wiring, it has given me a more stable connection.  I will see I can borrow a Speedtouch to check it out.  I am still concerned that the noise increase which sometimes hits 18dB is excessive - it's a 50 plus times reduction in signal
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 06, 2008, 10:15:35 PM
Don't know if you are still around Ba4ger - can you help with this one

The AR7 issue confuses me greatly - came across this quote from a Thinkbroadband article

The AR7 problem highlighted appears to be more to do with frequent re-syncs in a short period of time with the modem refusing to connect at a slower, more sensible, speed. With the BT Wholesale Max product, this can result in an increase in the target noise margin, i.e. sacrifice speed for stability.

What is not obvious for those quickly reading up on this issue, is that different modems using the AR7 chipset can actually perform very differently on the same telephone line. We have a number of AR7 based devices and the Netgear DG834G does disconnect a number of times in the evening on a noisy line, while a Solwise SAR-600E and 600EW appear to be highly stable. The line in question is not of the best quality, and it has two master sockets and a star configuration which can mean transient noise can have a great effect on stability.

What I'm confused about is whether the AR7 issue on noisy lines is a failure to resync when noise margins drop, hence effectively increasing noise margin by trying to hold on to an unrealistic sync speed, and eventually collapsing into a heap when the noise margin deteriorates beyond the point of no return.  When you switched to the Speedtouch you saw a more stable noise margin but did you sync speed drop.   
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 09, 2008, 05:16:57 PM
Hi there,
No the sync has always been roughly the same, whether I'm using the Netgear, 2Wire or Speedtouch.

My 'target' SNR is 12db (thanks to a summer storm) this has stayed the same which ever router I've used.
My lines syncs just over 4000kbps on my line with 50db attenuation.

For me (on a MAX product) the biggest issue was losing sync messed up my IP Profile for another 3 days!!!
The Speedtouch has sorted that.

As I've mentioned (I think) it all depends on your line, DSLAM chipset, etc.
As far as I'm concerned buying a Speedtouch 585v6 for £30 (new from eBay) has been the best £30 I've spent for many a year!
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 09, 2008, 10:46:25 PM
That's interesting that sync did not drop.

I've got another engineer coming in a few days, who I'm going to bury in in Routerstats and try to convince him that an 18 dB decrease in noise margin is not acceptable on a regular basis.  I've got a couple of weeks worth of Routerstats plots now and aside from the usual 3pm decline I'm also seeing  very sharp drops in noise margin down to  -4dB, during what I regard as the stable period (prior to 3pm), but they are sudden - gone within a minute and resyncs are to the same speed- but I may get 2-5 within an hour.  This seems to happen every 4 days or so.

I wish I had found routerstats earlier, as all I used to able to say to the engineers was that my IP profile had been hammered due to disconnects, which my ISP was telling me I was getting, although  I wasn't aware they were occuring.  Now I can see what is going on and I'm hoping I will get a bit more attention from the engineer.  If I could pick up my IP profile via routerstats that would complete the story.

If I still get no resolution I will lob out £30 ish on a Speedtouch as you suggested.
Title: Re: Very high noise margin drop in afternoon
Post by: Azzaka on January 10, 2008, 09:06:31 AM
Don't know if you are still around Ba4ger - can you help with this one

The AR7 issue confuses me greatly - came across this quote from a Thinkbroadband article

The AR7 problem highlighted appears to be more to do with frequent re-syncs in a short period of time with the modem refusing to connect at a slower, more sensible, speed. With the BT Wholesale Max product, this can result in an increase in the target noise margin, i.e. sacrifice speed for stability.

What is not obvious for those quickly reading up on this issue, is that different modems using the AR7 chipset can actually perform very differently on the same telephone line. We have a number of AR7 based devices and the Netgear DG834G does disconnect a number of times in the evening on a noisy line, while a Solwise SAR-600E and 600EW appear to be highly stable. The line in question is not of the best quality, and it has two master sockets and a star configuration which can mean transient noise can have a great effect on stability.

What I'm confused about is whether the AR7 issue on noisy lines is a failure to resync when noise margins drop, hence effectively increasing noise margin by trying to hold on to an unrealistic sync speed, and eventually collapsing into a heap when the noise margin deteriorates beyond the point of no return.  When you switched to the Speedtouch you saw a more stable noise margin but did you sync speed drop.   

The article itself does mention a lot about the AR7 fault/issue. Currently there is no stable modem code for the AR7 chipsets. I would suggest trying a non-ar7 chipset router to start but getting the stats and proving to BT that the line is unstable is also Great.

The issue appears to manifest itself when the SNR margin jumps either up or down in succession, and also when interleaving is enabled on the line. What i feel normally causes the issue when the SNR margin drops or rises, is the LOM or Loss of Margin written into the modem code. This piece of code tells the modem to resync when the SNR changes. By doing this the modem is constantly resyncing and not becoming stable (hence the intermittent issues we see.) in regards to the Interleaving, we are still looking into this, but it appears that when Interleaving is enabled then the modem takes the bad packets and stores them. When this happens the modems tables fill up and then eventually drop, again causing a dropped connection and in some cases an intermittent connection, depending on the quality of the line.

The other issues we see are No Sync and Auth issues. There is no hard and fast rule for any of them at this point, however I have been working with Infineon, BTW, and Netgear to try and find a stable piece of modem code that works on the existing infrastructure. With saying this, i want to make sure you understand that it is not the fault of the Modems chipset nor the line alone, however it is caused by both not being able to work together. I do not feel at this point, that the DSLAM has any effect on the AR7 chipset directly to cause the issues we see.

Title: Re: Very high noise margin drop in afternoon
Post by: graevine1 on January 10, 2008, 11:02:04 AM
Azzaka, that was extremly well put, BUT, Someone has to take responsibility for this state. Or, is the above mearly an attempt to a Political get out, with a capital P. Sorry but this had to be said. As the above appears to only (as it has been found) to be "spotted" to occur with one router at present then may more found to suffer later? I shall enjoy our next conversation when we meet. However we are still being 'shuffled' in respect to many stories concerning the possible glitch in the internal communication between the Broadcom and "A" hardware in the DG834N series router that many are also hinting at! Is anyone further down the line in that matter?
Title: Re: Very high noise margin drop in afternoon
Post by: Azzaka on January 10, 2008, 11:08:45 AM
I am little further and I know I owe you an email which will; be going out today. I have been busy training the last few days. As for the wireless issue. It is with certain chipsets. I am going to be talking to Netgear next week , but i think the easiest is to change the channel.
Title: Re: Very high noise margin drop in afternoon
Post by: Ezzer on January 10, 2008, 11:11:13 AM
Hi there, I've only posted once before so far & funny enough what your describing sounds very much like some thing known as REIN as it affects you at specific times. I've copy & pasted this again with some modifications (sorry it's a bit long winded) If you do have a REIN issue I'm afraid it's a bit of a Black art in tracing the source some times but I hope it may be of help (KITZ maby it could be handy as another catagory on your web site ?) here goes...

The effect known as REIN or Repetitive Electrical Impulse Noise.

   Anything electrical produces some radio noise/s. It’s just a question what frequency, type of noise, & strength, and then if this combination is something ADSL can hear & is sensitive to.

    If you suspect there is something interfering with your broadband, get an am/mw radio & tune it to 612Khz. if you hold the radio next to an LCD screen for your pc as an example you would hear a distinct noise. This should fade away if you move the radio a quarter to half a meter away. Hold it by your modem/router & you'll hear the DSL signal.

    If you get a distinct noise enveloping a larger area, then this may be picked up by your router & causing an snr problem (or even drop of sync), By using the radio you may be able to get an idea of where the noise is coming from. Switch the suspect appliance off & retest your DSL connection. (by distinct noise your looking for a clear Buzz, whistle, clicking etc. white noise or a general shhhhh noise is less likely to be the problem same as any radio broadcast. in the south of the UK you may hear a french radio station from around 612KHz)

    Be aware any noise heard on the radio is not always affecting your DSL connection, and you may still have REIN issue in the area which will not be picked up @ 612Khz, REIN is often notoriously difficult to pin-point. This method can be a bit hazy so don’t rely on it  completely by any means

    X-mas lights are a classic cause, noisy electrical appliance with a long length of wire (now an antennae). Some times you could cure it with a ferrite sleeve (that small cylindrical thing you normally see along your monitor cable which doesn’t seem to do anything) You can get these from electrical suppliers such as Maplin.

    Last full blow REIN fault I worked on  affected at least 3 customers within an 80m diameter, eventually found it to be caused by a LCD monitor for a pc, this sent a strong REIN signal feed back along the mains cabling affecting the local area. Referring to you previous appointments with engineers, it sounds as their doing exactly the right thing where often we may try & tweak, modify, change something even though no fault is found during the visit rather than say, tests ok so good bye & do nothing. The problem with broadband faults unlike normal phone faults is that we don’t get a means of a test which says the line condition is X so we can then prove it to location Y so we can fix the problem. Broadband is more like take an educated stab at trying this, now what do we get?

An Official explanation of REIN:
REIN (Repetitive Electrical Impulse Noise) is noise from the power network that is induced into the telecommunications network. Normally there is little interference from the two co-sited networks, in certain circumstances however electrical interference can be induced into the telecommunications network causing a degrading of service to the telecommunications end user. It must be remembered that the localising and resolution of REIN problems is not an exact science the information contained in the article is intended as a guide. Your own experiences and local knowledge.
Examples of REIN sources:
•   A current imbalance between two power carrying conductors (Earth leakage fault).
•   Faulty thermostats (Central heating, Immersion heaters).
•   Electrical power supply units (Laptops, Routers, Plasma TVs).
•   Industrial/Commercial power usage (Electric Railways, Electric fences, Electric motors).
•   Decorative electrical items (Christmas tree lights, Touch lights).
•   Security systems (PIR lights switching on and off).
•   Digital Communication Receivers (Satellite and Freeview set top boxes).
•   Internal power and telecoms cables run close together at the End User.
Title: Re: Very high noise margin drop in afternoon
Post by: Azzaka on January 11, 2008, 11:20:00 AM
Hi Ezzer,

Please do not take any disrespect with my comments, however what i was suggesting is not a REIN issue. I have spent the past 6months looking at the AR7 chipset issues and after working with both BT and Netgear, we may have a new code for the AR7 to fix the drops and auth issues.

I have a meeting with BT next week and hopefully this should prove fruitful. In the case of REIN you would normally see set patterns and to the drops, and in most cases the intermittency does not stop when the modem is changed.

However after all has been said, i am sure there is a lot of people who read these forums that do and will appreciate your good and accurate explanation with regards to REIN and DSL connections. This is something we seldom receive in a lot of cases.
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 11, 2008, 01:11:17 PM
Hi Azzaka

It is encouraging that you may be getting to the stage of updating AR7 code to resolve the current issues.  Is this likely to be able to be applied to all AR7 routers or only to the Netgear ones ?.  - for instance the SAR 600EH that I have.

I've got an engineer coming this afternoon to have a look at my line.  Hopefully he will be able to find something to fix.  If not then I'm stuck with buying another router, which I'm reluctant to do having only recently bought the SAR which has the advantage of hanging on down to -3dB or so.  Also I feel that my line is flaky and is a contributory factor to my problem, if that is not fixed then another router may not fix the issue.   However I may have no choice. 
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 11, 2008, 01:22:31 PM
Hi Ezzer and welcome to the forums.

Excellent post.  In actual fact I did start something on this a few months back but never got around to completing the page. :/
(Anyone who knows me, knows there is tons of stuff I want to put up and its always an ongoing task).
Rather than re-invent the wheel, Ive "slotted" your post in the middle of something else and given you credit for the applicable bits,
that way at least it gets published today - rather than being sat in my "to dos" :D

REIN faults (http://www.kitz.co.uk/adsl/rein.htm)
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 11, 2008, 01:37:58 PM
>> however what i was suggesting is not a REIN issue.

Possibly this thread has got confused with 2 lines of thoughts. I think Ezzer was responding to Mikes orginal post which could well suggest a possible REIN fault.

>> i am sure there is a lot of people who read these forums that do and will appreciate your good and accurate explanation with regards to REIN and DSL connections. This is something we seldom receive in a lot of cases.

It is something that does crop on on occasions therefore my reasoning that it does deserve a mention on the main site.
Most zen users by nature are more adept at tracking down their own faults, therefore may pick this sort of thing up before even approaching the ISP.
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 11, 2008, 01:39:57 PM
>> I've got an engineer coming this afternoon to have a look at my line. 

Good luck mike - remember to show him the logs showing what happens, and also ensure that you mention you have tried a couple of different routers which also display the same symptoms.

Let us know how it goes.
Title: Re: Very high noise margin drop in afternoon
Post by: Azzaka on January 11, 2008, 02:36:44 PM
Unfortunately it is only the Netgears at this stage, however I will be contacting another company next week as one of their customers was told that a certain firmware would fix the fault, which it hasn't.

I will let you all know how it goes. And we all ask that you do the same.
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 11, 2008, 06:54:51 PM
Well the engineer has been and gone.  Showed him the routerstat graphs with the three o'clock drop off.  Said he hadn't seen anything like that before, but the lines locally were crap.  He felt that as the line appeared OK until 3 ish that it wasn't a cabling issue.  So he thought it worth trying a lift and shift, which he went away and did.  He came back and checked sync/errors with his modem (non AR7 I assume) and sync'd at 2600 with virtually no errors.  We then connected through my (AR7) SAR600EH and sync'd at 4100 at a 6dB noise margin.  I have never seen a sync this high, normally I sync at 2200-2400 with a 15 dB noise margin. However I read somewhere that you loose about 600-700k of sync speed for every 3dB of noise margin increase, so I guess that the two situations are equivalent. When lift and shift occurs does this reset the target noise margin to the 6dB standard, or am I in a retraining mode ?.  Currently at -4dB, so it hasn't cured the noise margin movement time will tell if it any more stable in practice.  Sync has just dropped to 3700, noise up to a giddy 2dB.

What surprised me talking to the guy was that they don't have a list of what previous engineers have done in trying to fix the issue.  He was asking me what the others had done.  They do have a list when its a telephone fault.  Seems an odd way of going about it, bearing in mind that broadband faults seem to be a bit of a black art, with a lot of suck it and see, also leaves the possibility of engineers swopping pairs backwards and forwards.  He also said they have two hours to fix the issue, then essentially they walk away.

He mentioned REIN but said this was a specialist issue and was not something that they could deal with.  The other option he suggested was to switch to a 2Meg fixed line, which he felt would be more stable. 

Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 12, 2008, 02:26:08 AM
>> He felt that as the line appeared OK until 3 ish that it wasn't a cabling issue.

I think I'd agree with that.


>> I have never seen a sync this high, normally I sync at 2200-2400 with a 15 dB noise margin.

Although Im not 100% certain, it does indeed seem like the lift and shift has probably put you back in "retraining".
Like you say the sync speed and SNR figures are relevant and will affect each other.

>> Currently at -4dB, so it hasn't cured the noise margin movement time will tell if it any more stable in practice.

:/
Possibly on a bit better line, but the huge variation in your SNR Margins would seem to indicate that something is still there which is causing interference. 

The DLM will need time to adjust and increase your target SNR ..  which will decrease the maximum speed which you can sync at.  Its possibly too early to tell, but from your observations so far.. whilst I hate to say it, it doesnt seem to have cleared the fault.  Did your graph dip in the same manner as previous days?

>> Seems an odd way of going about it,

Indeed - I would have thought they must have notes somewhere?

>> He mentioned REIN but said this was a specialist issue and was not something that they could deal with.

They being BT? or within his particular job description?   Sometimes issues are passed on to SFI who may attempt to do something.  It all seems to depend on the engineer pressing this further based on where he feels the fault may be coming from. If they feel its in the home then this is certainly outside their remit.

>> The other option he suggested was to switch to a 2Meg fixed line, which he felt would be more stable. 

It probably would be...  but it could also be considered an easy cop out for BT if they dont know what to try next. :(
Title: Re: Very high noise margin drop in afternoon
Post by: mr_chris on January 12, 2008, 03:24:12 AM
>> The other option he suggested was to switch to a 2Meg fixed line, which he felt would be more stable. 

It probably would be...  but it could also be considered an easy cop out for BT if they dont know what to try next. :(

Don't forget you'd lose your additional upstream too if you got switched to a 2Mb fixed line. Whilst it may keep your SNR high enough to prevent disconnections, it wouldn't really solve the issue, just mask it.

Have you ever managed to try another router on the line? Perhaps it might be worth a shot.

Also, do you switch the router off at night? If so, leaving it on would keep the line synced at its lowest speed, so it wouldn't keep resyncing every day. Forgive me if this has already been suggested.

As regards REIN, I think it's only in the remit of SFI to investigate REIN issues.

Actually, having not heard the term in widespread use before very recently, it seems like REIN is set to be the buzzword of 2008, doesn't it! ;)
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 12, 2008, 09:36:02 AM
Well the engineer has been and gone.  Showed him the routerstat graphs with the three o'clock drop off.  Said he hadn't seen anything like that before...

Hi MikeS thanks for the update, sorry to hear you didn't get a fix.

Your SNRM dropping off at dusk is fairly common - especially for those of us on longish lines. As I mentioned earlier my situation is very similar to yours.

Not surprised about the BT comments etc. - my experience has shown that ALL the OpenReach engineers I've spoken to haven't got a grasp of things!  I'm not saying they are all like this, but the dozen or so I've spoken to in the last two years (mostly doing work for my neighbours not me) don't seem to have a clue. I've asked a few if they know about IP Profile (BRAS) etc. when they've been playing with peoples connections (we're rural/overhead) up a ladder, and quite often get the plug pulled with no warning. They all just shrug their shoulders and say "that's the other lot...". Not one has known what line attenuation is, I could go on.

Try a Thomson Speedtouch 585v6 for around £30 and see if it improves things for you as well  8)
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on January 12, 2008, 10:04:35 AM
The regular OpenReach engineers are employed as telephone installers and repairers. They're not trained in ADSL, or expected to know anything about it. So it's no surprise that they don't understand the specialist ADSL terms. They do have some engineers who are ADSL trained, but you won't encounter these so often.
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 12, 2008, 10:40:07 AM
The regular OpenReach engineers are employed as telephone installers and repairers. They're not trained in ADSL, or expected to know anything about it. So it's no surprise that they don't understand the specialist ADSL terms. They do have some engineers who are ADSL trained, but you won't encounter these so often.


We're going OT but,
On one occasion the one's in my lane were all wearing OpenReach logos on their clothing etc. I asked them if they were broadband trained engineers, they 'puffed their chests out' pointed to the logo and said they were trained broadband people not 'wire monkeys'. Then I asked if they knew about BRAS/IP Profile, attenuation, etc. - they went all sheepish and said "arh, that's the other lot"!   

As I said, I'm sure it's not all the OpenReach people but my experience (talking to at least a dozen engineers) has been poor.
Title: Re: Very high noise margin drop in afternoon
Post by: shape on January 12, 2008, 06:39:02 PM
Hope you don't mind me adding my tuppence worth.
After my lift and shift my target noise was reset to 6db.
I've just had a final SFI adsl engineer visit, who looked rather perplexed when i showed him my router logs, He kept saying it syncs at good speeds apart from the evening where it has poor sync's, so not that bad he thought.
I agreed yes, but what of my bras, ip throughput will never rise.
He looked confused, I added it would be fine if I was with talktalk as there is no 3day period.
When he visited he told me everything had been done, and phoned somewhere to check if a d-side swop had been done.
Was quite funny as apperantly loads of lines had been moved onto the new telegraph pole, but HQ knew nothing about it as there system had not been updated.
They where arguing with him that he had the wrong telegraph pole, as there was only one line on it, he almost lost it saying i'm looking at the bloody pole now and it has a half a dozen lines on it, lol.
Shows they don't keep the system updated.
He had no ideas what to try next, suggested fixed rate speed, i refused saying i'd lose out on upstream for my gaming.
He wanted to refer it to a REIN trained engineer, but said he hasn't a code to do that.
I suggested ringing my ISP rep for him, which I did.
He explained to my rep he had no code for REIN investigations, and this bit got me, he actually said we normally just con the EU (end user) off!
My rep told him he would call him back after he spoke to his boss.
He did stay for an hour plus chatting and drinking tea, lol.
He confused me, as although he said he wasn't REIN trained, he told me a tale where he was out in a area suffering disconnects on many user lines.
They found it by accident, well away from reported affected homes, was a guys dodgy sky box, blurting noise down the phone line, affecting loads of homes.
Sorry to waffle on.
:-)


Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 12, 2008, 06:53:22 PM
I think I'm definitely in re-training mode.  Started up this morning sync at 4300 and 6dB, then noticed interleaving was off (it has been on for the last 6 months). Held 4300 until 3.30 then dropped to 4000 then to 3800, currently bouncing around 2dB, will see what the rest of the evening will bring.  currently I feel that the line is a better - previously I would have been at 2300 and 2dB.  Need a bit more connected time to see if this is consistent.  I'm still puzzled why the BT modem sync'd at 2500-2600 (3 different tests) and I sync'd two minutes later at 4000 on my router.

In answer to some of the queries

Kitz
Yes the line dropped off at the same time though not so severely
Engineers notes - they do write them but they are difficult to access, requires a few phone calls I'm told. This is crap Openreach procedures, they should be provided automatically with the visit list.
REIN beyond the competence of the engineer, he said they had been told about it but just as a phenomenon - could sometimes be picked up on medium wave radio sort of thing.   

Mr Chris
Normally I switch the router off at night, I will leave it on as I seem to be in training mode.
I have tried two other router and a couple of modems, unfortunately they were all AR7 chip jobs and showed the same pattern.  The SAR 600EH I'm currently using is by far the most stable in the sense that sync drops are less frequent.  I think this a 600E with a built in homeplug.  The homeplug issue caused consternation with the engineers.  They  asked whether I was wired or wireless, wired I said.  Can't be they said you have only one ethernet cable.  So I had to explain about homeplugs, they had never heard of them.

General comment on the engineers I've had 6 now.  All have been polite, helpful, listened to me and tried to fix the issue within their limited palette of options.  None of them seemed to have much knowledge on broadband max.  I was getting comments like 'SNR and DLM, sorry that's a bit over my head',  'once the line goes into the exchange we don't know what happens'.  The general feeling I got was that they were shifted from voice line work on to broadband with very little additional training.  I think it's a massive increase in technical content going from voice to broadband max. Consequently I think this is a BT/OpenReach lack of training issue rather than an engineer issue.   A couple gave me the impression that they disliked maxbroadband work because all they could do was 'a suck it and see approach' - switch pairs, lift/shift, redo junction box connections etc and see if it made any difference, whereas on voice lines they could actually find and fix issues.

Another general comment on routers.  I have trawled the net for info on my problem and consistantly came across many comments like Router X cured all my problems, wonderful piece of kit,  then another comment saying Router X was total rubbish don't waste your money. I've come to the conclusion that similar spec routers may well perform very differently under specific line conditions - noisy lines, long lines, fast noise margin swings etc.  If that is the case how the hell do you go about choosing a router - aside from assuming you'll probably have to buy two or three before you get the right one.  I think I am going to have to buy a Speedtouch.  I guess BT are the only people who can test routers under different line conditions - would be a nightmare for them commercially.  Just resync'd to 3680 - time to go

Sorry for going on and thanks for all your help and advice



Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 12, 2008, 08:22:37 PM
I had a rather long and interesting convo with Azzaka from Zen yesterday about the AR7 chipset issue.  It could be a possible cause and we did discuss quite a few different scenarios and situations when this could occur.  It is kinda random and yes sometimes a change of router will remedy the situation, but the gist is that the AR7 is a good chipset, theres just something else going on... hopefully more info will come out soon and netgear are working with them on this and hopefully different firmware will be released soon.

I'd hate for you to have to fork out for a new router and then find the problem is still the same..  it there anyone you know locally that could perhaps lend you their router for a short while for testing purposes?  Even if you cant get hold of a speedtouch, try one of the other broadcom chipsets such as a Voyager 2091/2100/2110
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 12, 2008, 11:13:07 PM
Hi Kitz

Saw some new speedtouch 510v6 speedtouch for 11 quid including P&P on ebay - do these have the broadcom chipset, if so may take a punt on one out of curiosity as much as anything else.
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on January 13, 2008, 07:02:34 AM
Apparently it does. More information Here (http://www.modem-help.co.uk/Alcatel/Speed-Touch-510-v6-ADSL2--Residential-Gateway.html). But it's a rather old router and may not have up-to-date performance.
Title: Re: Very high noise margin drop in afternoon
Post by: setecio on January 13, 2008, 10:22:16 AM
Apparently it does. More information Here (http://www.modem-help.co.uk/Alcatel/Speed-Touch-510-v6-ADSL2--Residential-Gateway.html). But it's a rather old router and may not have up-to-date performance.


If you use the Thompson chooser for a home 1 user modem, it still comes up as a current product
http://www.thomson-broadband.co.uk/products/Details.asp?ProductID=532

Title: Re: Very high noise margin drop in afternoon
Post by: roseway on January 13, 2008, 11:02:49 AM
So it does, you're right. The 510 series has been around a long time, but the v6 is still current if you only want a single user, non-wireless solution.

Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 14, 2008, 05:32:58 PM
I think my lift and shift has actually made a small improvement.  The new DSLAM port seems to be relatively gentle, starting sync was 4320 day 1, at 6dB and IP profile 3000, post 3 pm  noise started to increase as per usual and had three downward resync's, but very small  3968,3776,3680.  Left it on overnight, as per Roseways suggestion, and the 3680 held which is good as my noise issue doesn't usually improve until around 7.30am.  IP profile held at 3000.  Prior to the lift and shift  on a good day I would have an IP profile of 1500, but I used to get savage cuts on resync, usual sync was 2300 and this would resync to 900-1000 with IP profile usually going down to 750-500K or even 250K (for 3 days) if there was another resync.  I assume this was because my target margin was 15dB, so clawing back from -4dB (when my connection drops) forces big drops in sync speed.  If that is right it is a big disadvantage with high target SNR margins, if they do get breached you will get hammered. 

Day 2 had one small resync upwards to 3744, followed by a resync down to 3712 in the post 3pm period. Then back to reality, sudden drop, resync at 2464, so much for the gentle DSLAM, IP profile dropped to 2000, still it's better than what I used to get.  Turned the router off at night.

Day 3 seems to be following pattern of Day 1 - starting sync 3968, followed by two small adjustments to 3776 and 3744 during the noisy period, IP profile still at 2000.

As my interleaving was switched off by the lift and shift I am seeing CRC errors, which I don't know how to interpret.  The router seems to cumulate errors until a resync, then starts again.  I have no idea at what level CRC errors should become a concern - how many a minute.  Can anyone help me on this.  I've asked for interleaving to be turned back on but that will take a few days.
 
Overall it is an improvement, the instability post 3 pm it is still there but the effects are not quite as severe.  Whether it remains this way only time will tell. Overall  I'm surprised by the very small reduction in sync after a drop (generally drops occur below -4dB).  Have attached router stats for day 1&2 - the red blobs are disconnects

Bought one of the £11 Speedtouch 510v6 off Ebay, will give that a go when it arrives.  Hopefully it will not join the pile of modems, routers, card readers, CPU's, memory cards, and general antique and next to worthless electronica which fill one cupboard.  If it doesn't work I'll try for an Engineer who has some specialist understanding of the process - not holding my breath though.


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Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 15, 2008, 01:07:28 AM
>> I have no idea at what level CRC errors should become a concern - how many a minute.

TBH I'm sure sure - there seems to be no hard and fast rule that Im aware of.
But the fact that youre running in minus SNR figures means that youre likely racking them up pretty quick.  This will have the impact that your throughput speeds during this period will be much slowed down.

>> Overall  I'm surprised by the very small reduction in sync after a drop (generally drops occur below -4dB).

I noticed that too when looking at the graphs which made me think perhaps there was one quick sharp burst which took the connection down... but then again being in -ve figures youre sailing close to the wind anyhow.

Looking at those graphs side by side shows a very obvious daily pattern.  It strikes me that the time it starts is about the time the kids will get home from school.  I know you say youre not particularly near your neighbours, but there are recorded cases where a faulty electrical item has knocked out adsl for a large portion of the street.

Something Ive also discussed with Azzaka with the ar7 chipset issue is the fact that the netgear is very good at holding on sync which helps a lot of lines..  however there may be some when the netgear should just say "ok enough" and drop the connection...  but instead it continues to hold on and rack up errors that perhaps it cant cope with.

This is possibly going to sound really stupid because I cant think of a technical explanation to do this, and it probably wont come to anything.. but next time the router gets down to -ve SNR rather than waiting for it to drop sync. Just try switching the router off completely from the power source and give it a total fresh start so it doesnt have a pile of errors stored.

ps can you tell Im now clutching at straws?
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 15, 2008, 04:14:57 PM
"I noticed that too when looking at the graphs which made me think perhaps there was one quick sharp burst which took the connection down... "

This was my feeling too.  I sample at every 90sec on routerstats and many of the small sync adjustments don't show as a disconnect, which I think means that the resync is occuring within the 90 sec interval.  Attached a trace of the whole of yesterday. Same pattern small sync adjustments.  Perversely the resync at around 2.00am resulted in a higher sync rate, which to my way of thinking kind of supports the sharp burst idea.  You can see that the line is noisy throughout the night until around 7 am ( this is typical behaviour) when it settles down until 3.30pm ish.  Basically I have a good line from 7am to 3 pm, outside of this period it is very noisy.  My IP profile has fallen to from 2000 to 1000 despite sync being maintained above 3000 during this period.  I wish I understood the DLM logic - its seems to be driven by the
number of resyncs.  What makes my problem so irritating is its impact on IP profile, I can live with the odd disconnect - most of the time I don't even notice them.

Sorry posted wrong graph

Speedtouch 510v6 just arrived gonna give it a go - let you know what happens

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Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 15, 2008, 04:16:28 PM
Sorry posted wrong graph

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Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 15, 2008, 09:50:20 PM
Well don't quite know what to say, the Speedtouch 510v6 ex Ebay arrived today and I connected it up about 1.30pm.  Very easy to set up even for me.  Turned on Routerstats and it sync'd at 4700, didn't trust that, looked very high so rebooted it sync'd at 4928 and 6dB.  Weather has been dire water pouring out of BT manholes and our drains so a good day to check it out.  Totally different from any previous router. All the other three (all AR7 chips) showed spikey noise margin movements plus a big drop off at around 3 pm (see graph from earlier post) .  So far the Speedtouch has shown only a slight decline  (2dB ish)  during the problem period post 3 pm. but none of the spikey ups and downs, all this when it is syncing at least 1000 higher. (attached routerstats trace).  The only caveat I have at the moment about the comparison is that yesterday I had interleaving turned off after the lift and shift. It was scheduled to be turned on today but I can't see anything on the modem stats that tell me if it's on or not.  I have to say when I had interleaving turned on in the past it made no difference to the spikey nature or the big drop in noise margin.  This may be a bit premature but I am cautiously optimistic.  b4dger had the same experience albeit with different Speedtouch model (sorry for being sceptical).  If this behaviour continues it does place a question mark against my AR7 router and its performance on my line, or to be balanced the DSLAM response to my AR7.  Maybe something Kitz can talk to Azzaka about. Will keep you posted when I have more data. 

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Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 16, 2008, 01:11:18 AM
Thanks for posting those - it certainly does look a lot better.

>> Maybe something Kitz can talk to Azzaka about.

We've discussed a few things. Azzaka is more knowledgable about the situation than me though.
One of the reasons why I suggested turning the router off last night is (as I said it may not make sense), but just a theory that the Netgear isnt handling errors too well and should be dropping the line instead of keeping hold.  I wondered if the rack up of errors was perhaps making things more unstable and a total switch off of the router may clear it for a while.
Like I said above though - clutching at straws, trying to find a solution.

>> Will keep you posted when I have more data.

Please do. :)
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 16, 2008, 11:25:14 AM
>>b4dger had the same experience

Glad things are looking better for you  ;D
I was worried I was starting to look like a 'spammer' by recommending you switch to a Thomson router so many times  :-[

I read and read and read about peoples low SNR experiences and went through a few routers along the way.
My router is the 585v6 running 6.2.29.2 firmware - this firmware isn't tweakable using the DMT s/w but many have reported it to be the most stable for them, I'd go along with that...

______________________________________________
My Router/SNR experience: www.hmmm.ip3.co.uk/adsl-snr
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 16, 2008, 06:03:36 PM
Attached a trace of the first full day with the Speedtouch 510v6 and a comparison with a day from the SAR 600EH.  They are totally different in style.  Both show a fall in noise margin from 3pm ish to 7am ish but the Speedtouch looks controlled and slowly drops 2-3dB whereas the SAR is all over the place, with drops of up to 10dB.  Both are from after my lift/shift.  Other differences, are that the sync speed is about 1000 higher with the Speedtouch and the line attenuation 52dB SAR, 54dB Speedtouch.

I started the Speedtouch up today during the noisy period (5pm) and sync was still high at 4680.

I am now talking about that which I know very little.  My impression is that once the line enters the noisy stage, communication between the SAR and the DSLAM seems to get ‘out of wack’  in some fashion, maybe one of them is playing catch up, I don’t know.  Then end result is large swings in noise margin which eventually result in a resync.  The very small changes on resync may support this.  They seem to be deciding that things were not as bad as they thought and relatively trivial sync adjustments are made (bearing in mind I’m dropping from -4dB), and on the last trace the resync was actually upwards. Because I’m sampling every 90 secs  I don’t know whether the noise spikes are actually much sharper than appear on the graph, if this is the case it could also account for the modest changes on resync, as the line would be back in a ‘stable’ state.  Sorry if this sounds like a load of rubbish I just don’t have the technical knowledge to put it more coherently. 

Azzaka raised an interesting point in another thread.  If the instability on noisy lines is due to code issues between the router and DSLAM whose responsibility is it.   Whose responsibility is it to check that communication protocols between router and DSLAM are compatible.  Good question


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Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 16, 2008, 06:34:22 PM
>>MikeS didn't say: "Thanks b4dger..."

No problem MikeS glad things are looking good!
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 16, 2008, 07:12:56 PM
Really sorry to interject this thread, it seemed a little more along the lines of my problem than I may have originally thought.

"You may have read my post about "Dropped connections, Resyncs, Flourescent lights, BT problem, Bit random - sorry"

@ b4dger... as you seemed to have had a similar problem with resyncs, (and the rest of you most helpful people).

Finally got an engineer out ( I asked if he could come after 5 when the line seems to be noisier, arrived at 3!) He checked line with his test router and got a no fault and very little crc error result! Suggested I keep on at BT if I am not happy!? Trouble is with his messing around with the connection of his router (which synced at one point at 2100!!?) and checking the crimps at the junction post, the lovely 'system' has interpreted that as a fault and I am at an even slower speed now (even though MY router has resynced for the second time since he left, 1st at 3616 and then again at about 5.30 at 3360), my actual speed is 1.7mb! I guess that should recover in a couple of days?

More to the point is maybe I can stop the resyncs with this Thompson 585 router you have tried successfully with. Are you still problem free? (sorry don't wish to tempt fate!) I have Netgear DG834Gv2 which I thought was well renowned for hanging in where all others failed? Just want something to hang on to my connection so I can boost my profile that elusive one notch! :) How easy is it to set up? What about wireless and port forwarding? Updating firmware etc. Any other ideas? I have read your 'story' - very interesting.

I also note MikeS has used the 510 with success.

Yours and anyone elses voluntary time consuming comments are VERY much appreciated.

All the Best

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 16, 2008, 08:25:25 PM
Unfortunately routers/modems seems to be a lot like frogs, you have to kiss a lot before you find your prince or princess.  I have tried 4 or so and they all showed the same characteristics ( they were all, although it didn't mean anything at the time AR7 chipset routers).  They were new selling Speedtouch 510's for £11 delivered on Ebay so after 5 engineer visits I thought I was worth a punt.  So far it seems to have worked for me, doesn't mean it will for you.   You do however have my sympathy.  I tried for engineer visits late in the afternoon but I think they have 2 hour slots for each visit, so 3 pm is likely to be their last visit.
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 17, 2008, 10:46:21 AM
Hi Ian1261,

Interestingly 2Wire are the only manufactures (that I've found) that actually make a reference to noise, and as in your case 'fluorescent lighting'.

From the 2Wire guide:
"High performance integrated modem. 2Wire’s technology improves DSL1 performance, especially for
homes further away from the local exchange. It also minimizes common interference found when other
devices (such as dimmer switches or fluorescent lighting) are in contact with the DSL line."


When I used a 2Wire monitoring the SNRM showed that during the day it was completely rock solid! But during the evening it still dropped more than the Thomson - hence my switch. But from what I've seen the 2Wire manages 'noise' in an impressive way so may help you with your lights.

My ADSL is important to me, so buying both a 2Wire (£16 delivered from Digidave) and a 585v6 (£30 delivered from eBay) to evaluate was well worth it. My Netgear DG834v2 was causing much pain with dropped connections and the knock on affects on my IP Profile!

I can't answer your 'Port Fowarding' questions etc. as I don't use that. What I can tell you is that the GUI on the Thomson is rubbish but you can do everything through CLI/Telnet. The reverse is true with the 2Wire, the GUI is excellent but there is no Telnet facility.

Good Luck!
________________________
www.hmmm.ip3.co.uk/adsl-snr
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 17, 2008, 04:24:46 PM
Hi there

Thanks for your replies, got home today my router had reconnected about 6 hours ago at 3584, so I thought I would see if the 1.7mb had improved yet - it was at 2.9mb!!! Well pleased! I wonder if that will be the case later today? I may invest in a Thomson in the hope it will hold onto those evening 'lows' and keep my profile up!

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 20, 2008, 02:10:40 PM
Ah well unfortunately not! Ordered a router will wait and see what happens when I get that. Incidently, I had a call yesterday from BT who asked if there was any improvement!?? after the engineer had been. I asked him how there could be as he had done nothing! The chappy from BT said he would get my profile reset? I asked what he meant and he said I would have to go through the optimization again! How that is going to help I have no idea but hey, I have had enough of trying to get someone to understand a simple  -  It was fine BEFORE you changed me from max to fixed and back again to max! It isn't rocket science something MUST be different ther end as I have exhausted all possible things (aside from the router) my end!

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on January 20, 2008, 03:22:47 PM
Frustrating, isn't it? Maybe the Speedtouch router will be more stable on your line, in which case resetting your profile might get you a better result.
Title: Re: Very high noise margin drop in afternoon
Post by: Ezzer on January 21, 2008, 08:24:51 PM
with reference to crc errors, crc are the most critical closeley followed by hec errors, rs can stand a lot more.

When I do a test I tend to run it for 5 mins, in that period of time for non interleaved 0-30 crc/hec errors are not unusual. once this creeps into 3 figures it becomes a problem above say 200-400 then your lucky to retain sync & dispite any quoted spped, you'll notice thing seem slower because the system is constantly going "what was that can you repeat that bit."
Interleaved errors seem to become an issue once they reach 4 figures & rs errors ok up to 10,000-14,000

The analogy I use is it's like reading a document with spelling & punctuation errors. the odd few, no problem. too many the document becomes illegible & you're constantly rereading bits. izzz ya vit lihke your spoolchucker ez goon a vit kwazy
Title: Re: Very high noise margin drop in afternoon
Post by: mr_chris on January 21, 2008, 10:39:09 PM
Nicely explained, ezzer - useful to know some thresholds for whats considered 'good' and 'bad'

Quote
izzz ya vit lihke your spoolchucker ez goon a vit kwazy

:lol:
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 21, 2008, 11:22:59 PM
indeed -

thanks for the explanation - good analogy too  :D
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 22, 2008, 02:39:05 PM
Thanks for that Ezzer, my error numbers fall into the OK category, so I guess I need not worry too much.  I was sent a 2wire  BT1800HG to try by Plus Net.  It syncs at about the same rate at the Speedtouch but shows a more spikey SNR trace.  (see attached) Overall I think it is a little less stable and has poorer control over SNR flucuations than the Speedtouch, but no where near as bad as that of the SAR600EH.  Both the Speedtouch and the 2Wire drop connection in the 1-2dB region whereas the SAR would not drop until -3dB.  Irritatingly the Speedtouch when it does drop seems to hold the dsl signal but drop the PPPoa connection which results in an idle timeout error and needs a software reboot to regain it, whereas the 2Wire simply resyncs. 

Plus Net have offered to call in a specialist REIN engineer, of which there are evidently only about a hundred in the country, and I think I'm going to take up their offer.  Even if the interference turns out to be out of anyones control, at least I now feel that my line is now much more useable with the Speedtouch or 2wire.  I have been operating at a IP profile of 3000 for a week or so now, whereas previously the best I got was 1500 and then only for a day or so.  Looking back it was a pity that all the routers I tried were AR7's, although at the time this wasn't an issue. 

Thanks to everybody for their help.

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Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 22, 2008, 08:26:06 PM
Quote
I was sent a 2wire  BT1800HG to try by Plus Net.

Full marks to the ISP for that one,  :thumbs:
I dont think Ive ever seen an ISP actually sending out a different chipset router to try before.
Recommend the user try to source one yes - but not actually send one out which  I presume is on loan?
Since PN dont by default ship out 2wires - it would appear who ever is dealing with your case really is doing all they can to help.

Quote
It syncs at about the same rate at the Speedtouch but shows a more spikey SNR trace.  (see attached) Overall I think it is a little less stable and has poorer control over SNR flucuations than the Speedtouch, but no where near as bad as that of the SAR600EH.  Both the Speedtouch and the 2Wire drop connection in the 1-2dB region whereas the SAR would not drop until -3dB.  Irritatingly the Speedtouch when it does drop seems to hold the dsl signal but drop the PPPoa connection which results in an idle timeout error and needs a software reboot to regain it, whereas the 2Wire simply resyncs.

Thanks for your mini-review between the different routers

Quote
Plus Net have offered to call in a specialist REIN engineer, of which there are evidently only about a hundred in the country,

Excellent news please let us know how it goes.
Once again credit to the agent dealing with your case for actually acknowledging that this is a problem for you.
All too often most of the big ISPs wouldnt either know what REIN nor an AR7 chipset is and you'd be stuck with your problem.
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 22, 2008, 09:28:15 PM
They (PlusNet) have been helpful).  I've had several phone calls from them, a large number of emails, plus the router.  I have been with them for a number of years, intially they were very good,  then they went downhill, inertia kept me with them really, but more recently they seemed to have got their act together.
Title: Re: Very high noise margin drop in afternoon
Post by: guest on January 22, 2008, 10:19:31 PM
Full marks to the ISP for that one,  :thumbs:
I dont think Ive ever seen an ISP actually sending out a different chipset router to try before.

AAISP are the only others that I know who will send you out another router to "try before you buy". They're not exactly a "normal" ISP though ;)

Well done to Plusnet (for once :P ;) ).
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 26, 2008, 07:12:15 PM
 ;D ;D ;D ;D THANKYOU THANKYOU THANKYOU THANKYOU  ;D ;D ;D ;D  To all of you who have offered invaluble advice to me.

I got myself a speedtouch 585, set it up and after a bit of messing about trying the router stats on that one and comparing to my netgear router I found that the speedtouch connected with a 15db margin whereas the netgear only 12db. Both fluctuated up and down at the peak periods but the thompson stayed connected where the netgear still kept dropping. So I decided the Thompson was the way to go. Connected at 3488kbps and that was 3 days ago (at 1.30pm today) and it is still connected!!! Hooray!! No drops (yet!). Keeping everything crossed it stays that way.  :) I now have the 3000kbps profile back that I had before everything went t1ts up!

The margin stays pretty much stable with little or no drops during most of the day and all night at 15db, drops down to about 10db between 7 and 8 in the mornings and around 5 to 11 evenings when it will fluctuate between about 13db and 9db, occasionally dropping to 6db. Is that pretty much par for the course?

I have listed the errors below over the 3 day up time (hooray again!), are they par for the course also? Couldn't get that info with the netgear!

Error Seconds (Local/Remote): 2,247 / 0
 
FEC Errors (Up/Down): 0 / 0
 
CRC Errors (Up/Down): 0 / 135,268
 
HEC Errors (Up/Down): 0 / 46,716

I have read other posts about the setting of the margin, and from that I am guessing that if my connection stays stable for a while my margin would be reduced and thus possibly increase the connection and in turn my profile? Mind you I don't care now if it doesn't as long as it stays connected!

So THANKS again to you helpful people out there. Keep it up. You are appreciated!  ;D

Ian

By the way did I say THANKS?  THANKS, THANKS AND THANKS AGAIN!
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on January 26, 2008, 10:42:22 PM
 :D

That's great news.
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 26, 2008, 10:49:09 PM
Brilliant news :)

Thanks for letting us know.
Title: Re: Very high noise margin drop in afternoon
Post by: b4dger on January 28, 2008, 11:31:03 AM
Another 585 success!
Glad it worked out for you...

PS. Looking at your errors (i.e. no FEC's) it doesn't look as if you have Interleaving turned on.
For a line like yours I think this would also help. Might be worth asking your ISP to turn it on for you (this isn't normally a problem) - the affect will be to make your line more stable (at the slight cost of your ping response).

Just a thought.
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 28, 2008, 02:53:52 PM
Would slower ping response mean slower speed/profile?
Ian
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on January 28, 2008, 03:18:05 PM
No, it's just a time delay between sending a request and the answer starting to come back. The data still flows at the same speed.
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 30, 2008, 06:36:47 PM
Hello all
Just come off the phone to BT (again) as connection is dropping out again  :(
Not terrible but enough to go back to lower profile!

b4dger - you were correct interleaving was off. They told me it was turned off (yes off) in order to stabilize the connection? I always thought you turned it on to do that?

Also - If bt lowered the target snr margin from 15 (which mine is set at I think) would that theoretically increase sync speed?

Couple that with my speedtouch router is it possible it may become more stable?

I hoped it would be more and had to coax the 'helpdesk' into getting my target snr margin reduced and i/l turned back on with that assumption.

Can someone please either confirm or correct my theory (which is based on all the info I have soaked up over the past few weeks!)

I suppose if I am incorrect I will have to go back to BT cap in hand  :-[ !

As Always your help is well appreciated.

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 30, 2008, 09:33:01 PM
>> hey told me it was turned off (yes off) in order to stabilize the connection? I always thought you turned it on to do that?

Correct. :)

>> If bt lowered the target snr margin from 15 (which mine is set at I think) would that theoretically increase sync speed?

Yes - the higher the target SNR then the lower the speed at which you can sync up at.
Whilst SNR Margin and Target SNR are related - then they arent the same thing.

Interleaving and target SNR are configurable attributes of the DLM.. 
whilst SNR Margin fluctuates depending on the (SNR) conditions on your line.


Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 30, 2008, 09:41:08 PM
Cheers Kitz

So target snr is the figure that comes up when you boot up the router, snr margin is the up and down fluctuation bit?

So bearing that in mind what I have asked BT to do (turn interleaving back on and lower target snr) was the way to go?

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 30, 2008, 10:20:53 PM
We as users never know for sure what the Target SNR is set at..  the best indication that we can get is by looking at the SNR Margin immediatelyafter the router has sync'd.

Have a read of An explanation of SNR and SNR Margin  (http://www.kitz.co.uk/adsl/linestats.htm) which may help you understand it a bit better.
Theres also a very good post by eric which may help too
http://forum.kitz.co.uk/index.php/topic,147.0.html

>> So bearing that in mind what I have asked BT to do (turn interleaving back

Interleaving does help stabilise many lines without affecting the sync speed so yes. :)
As regards to the target snr - that depends on how much the snr on your line actually fluctuates/needs.  Decrease it too much and your line could become unstable again.
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 30, 2008, 11:36:37 PM
Cool, all makes sense.

My connection with the speedtouch seems to fluctuate far less than with netgear, at very worst a fluctuation of 6db at any given time in the 'noisy periods', hardly moves during other times, so if they could set it at 12 or maybe even 9 I reckon I may be ok, especially with i/l on too.

Does that sound optimistic or realistic?

Ian

(just out of interest I checked my neighbours connection, it has i/l on, is synced (for 4 days now) at 3616 with target snr at 12db and has 3000 profile)
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on January 31, 2008, 12:35:35 AM
yeah going down in a stage rather than a big jump back down to 6dB is more sensible.  BT are probably more likely to agree to 9 or 12dB rather than straight back to 6dB anyhow.
If it doesnt fluctuate more than 6dB - then 9dB should be fine.
Title: Re: Very high noise margin drop in afternoon
Post by: MikeS on January 31, 2008, 02:00:20 PM
Hi

Below is a Plusnet quote from Oct 2007

Sometimes though, you will see cases where someone has had a fault on their line that has caused an increase in a customer’s SNR margin. This is often done as part of BT Wholesale’s diagnostic process or due to the actions of their Dynamic Line Management systems. The problem arises when the fault is fixed or the condition that caused the SNR increase is no longer present - Customers are sometimes left with an artificially high SNR margin and a lower than optimal sync rate. This is when getting the target SNR back to how it was proves to be rather tricky! I’m fairly certain that BT never envisaged that Service Providers would be asking them to lower a customer’s target SNR, as it’s this sort of thing that their automated systems are built to manage. However, we’re now in the situation where we see a number of  these requests and more often than not, the only way that we’re able to get them actioned is by raising a fault and escalating it to a Team Leader within BT Wholesale’s Faults team. This is obviously far from ideal.

Because of the measures required to restore the SNR target to its original value, it will often take a considerable amount of time for such a request to be actioned - This isn’t great for our customers or us and can be very frustrating at the best of times. We have to raise a fault which will then spend time bouncing between us and BT Wholesale because their systems and processes were not designed to deal with such a request. Eventually the fault will get escalated within BT however at this point the customer, us and BT Wholesale have invested a lot of time and resource for what is basically a very simple change, which BT Wholesale have the tools to make.

In other words don't hold your breath !
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on January 31, 2008, 04:01:02 PM
Tell me about it!

Just spent another age on the blower to someone who came back with - engineers have changed some wires at the exchange please monitor closely and let us know if you are still having problems! Connected at 3424 now, good enough for 3mb I believe, will have to wait and see I guess.

The thing is I asked  bt to simply reset the target snr to 12 or 9 and to turn i/l back on which should have hopefully sorted things, instead they tell me they have done something different, bloomin' trouble is I have to go through practically the whole case and reasons before I get anywhere and no doubt I will now have to go through the same process again next time to someone else who will probably give me some old cr4p too!

Why oh why can't a simple request be actioned???

Sorry, I am getting annoyed now! I have gone to the point of no return - I will get this sorted!!! ???

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 01, 2008, 08:48:41 PM
Hey Kitz - Your explanation of Mike s Help with understanding snr rocks!

Which even more cements my request to get my target reset to 9db and interleaving back on (which hopefully assists during the noisier times), was the path to take.

Surprisingly, I got a call today from bt following up yesterdays fiasco and the most helpful chap seemed to understand my request!
He called me back after talking to wholesale and told me that they were going to do the reset and that he was now going to request i/l to be turned back on.
Apparently this is done through a different department!?
Anyway he said it could all take up to 24hrs so he would call me back tomorrow to see how things were!

Why can't all of the helpline people be that helpful?!

Anyhow the proof of the pudding etc.
Fingers crossed :)
If this does work for me, cheers to you and all of the rest of you helpful folks out there. Mind you I don't know what else to try if it doesn't work? :-\
Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 02, 2008, 01:12:26 AM
Sorry Ian I must have somehow missed your post yesterday - it wasnt a deliberate ignore :blush:

>> I got a call today from bt following up yesterdays fiasco and the most helpful chap seemed to understand my request!

yay :)

>> Apparently this is done through a different department!?

Yes very possibly.   Getting interleaving turned back on should be fairly easy..  judging from the post mike kindly posted though it does sound as if its not an easy job.  I had heard elsewhere that it was getting harder for ISPs to request this.
Sometimes though it may just be a matter of speaking to the right person at your ISP who has the perserverence to follow it through with BTw.

>> Mind you I don't know what else to try if it doesn't work?

Lets hope it doesnt come to that.
but >> "I got myself a speedtouch 585"

so we possibly have another trick for you to try called DMT ;)
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 02, 2008, 12:16:59 PM
Thats dangling a carrot!?  ;D
See what happens today, at the moment though no change or so it seems, but I have just connected (left router off last night) at 3744, 3580, 3520 in the last 5 mins! snr still shows on connection at 15 and no sign of i/l yet.
Still, I must be optimistic! :)

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 02, 2008, 12:39:13 PM
It may take a few days to go through to BTw.

>> Thats dangling a carrot!?

Since you now have a speedtouch 585, a nice little tool called DMT tool works with it.  You need v7

 DMT v7 tutorial (http://www.kitz.co.uk/tute/DMTv7.htm)

Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 02, 2008, 02:34:55 PM
Very interesting!

I am to understand that I can change the target snr myself? Does that make the change at the exchange or is it more like a virtual target snr through the router? I am still connected at 3520 but the margin is at 16 at the moment (and according to routerstats has been since the sync, give or take 1db) but it is quiet time at present. I think it may be prudent to wait and see for a while if bt do reset to 9db, but I also think it may be wise to have i/l on too for the evening 'noisy' period, would you agree with that? (My attenuation is normally @ 52db). Hopefully they will do it both at the same time!

Cheers Kitz,

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on February 02, 2008, 03:31:53 PM
If you use DMT to tweak the noise margin, it overrides the value set at the exchange. It doesn't give you total control to set the margin to anything you want, but allows you to offset the value set in the exchange by roughly +/- 6 dB. What would normally be advised is to change it by small amounts at a time and see how it goes.

As regards interleaving, yes, it will normally help a lot with coping with noisy periods. I'm rather surprised that you're not interleaved already, because it's usually the first thing which gets applied if a connection is anything less than perfect. If they deliberately switched it off as you were told a few days ago, that sounds as though someone made a mistake.
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 02, 2008, 05:17:19 PM
Hi roseway

Thanks for your reply.

Yeah thats what I thought, I kept asking the helpline why that was the case as I have always had i/l on, no-one could answer me why!
(Just so I know i/l is back on can you confirm I am right in thinking I should see FEC errors clocking up? Hopefully I will see at the bottom of the stats page - interleaving on - but just incase it doesn't display.)

So if they never get around to resetting my target snr, theoretically I can slowly drop the present 15db down to 9db and see how it goes? Conversly, if they DO reset and it proves too low I can bring it up a little? Does that sound about right?

I can almost see light at the end of a 2 month tunnel!  :)

Ian

Title: Re: Very high noise margin drop in afternoon
Post by: roseway on February 02, 2008, 06:39:47 PM
Yes to all three questions. :)
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 02, 2008, 08:50:01 PM
Cheers roseway

Cheers Kitz

You make a great forum tag team! Much appreciated. Will let you know how things develop.

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 03, 2008, 04:15:21 PM
good luck :)
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 07, 2008, 05:28:58 PM
Hi there, Looks like i/l is back on - fec errors clocking up, but connecting and showing target snr at 15db still. Maybe its time to try DMT!?

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 07, 2008, 06:21:33 PM
>> Hi there, Looks like i/l is back on - fec errors clocking up,

Dont worry too much about those.  FEC errors is just a count of how many errors have been corrected by having interleaving (http://www.kitz.co.uk/adsl/interleaving.htm) process and error correction switched on.

>> target snr at 15db still. Maybe its time to try DMT!?

possibly so :/

How high are your error counts now?
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 07, 2008, 06:31:41 PM
Hi Kitz
Yeah thats cool about the fec count, I understood that from one of your previous explanations somewhere on 'ere. In fact it is keeping the crc count down! Stats from the latest boot up (been away a few days so this is the 2nd boot up since returning - pc was playing up so had to restart everything!)
1st synced at 4000kbps - couldn't believe it!
2nd @3552 rest of stats below;

Uptime: 0 days, 1:51:38
 
Modulation: G.992.1 annex A
 
Bandwidth (Up/Down) [kbps/kbps]: 448 / 3,552
 
Data Transferred (Sent/Received) [MB/MB]: 1.67 / 6.20
 
Output Power (Up/Down) [dBm]: 11.5 / 19.0
 
Line Attenuation (Up/Down) [dB]: 29.5 / 52.0
 
SN Margin (Up/Down) [dB]: 19.0 / 14.5
 
Vendor ID (Local/Remote): TMMB / TSTC
 
Loss of Framing (Local/Remote): 0 / 0
 
Loss of Signal (Local/Remote): 0 / 0
 
Loss of Power (Local/Remote): 0 / 0
 
Loss of Link (Remote): 0
 
Error Seconds (Local/Remote): 7 / 0
 
FEC Errors (Up/Down): 0 / 109,039
 
CRC Errors (Up/Down): 0 / 492
 
HEC Errors (Up/Down): 0 / 428
 
 
 

Look ok to you?

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 10, 2008, 03:47:47 PM
Hello again

3 days in, still connected, ip profile up to 3000 now  ;D

Doesn't look like target snr has been reset yet but at the moment things are looking good. Maybe T. snr will come down as time goes on, will I have to reboot router to see if that has happened?

I think I will wait and see before trying DMT?

Error counts are now:

FEC Errors (Up/Down): 0 / 1,015,106
 
CRC Errors (Up/Down): 0 / 2,454
 
HEC Errors (Up/Down): 0 / 1,994


Thanks for everyones help.

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 10, 2008, 03:55:03 PM
>> 3 days in, still connected, ip profile up to 3000 now

Cool :)


Those errors (CRC/HEC) are still racking up... but if they are slowly accumulating over a period of time and as long as you arent seeing any problems/slowness on the line then its probably ok.  Its an indication that at times your line is a bit noisy.

>> Maybe T. snr will come down as time goes on, will I have to reboot router to see if that has happened?

There is nothing actually defined anywhere as to when or how the Target SNR is supposed to come down..  theres been various figures mentioned.. but it does seem to vary from line to line and nothing seems to be set in stone on that one.
You wont notice it until a resync though to pick up the new figure... cause the only way we can tell what it is.. is by looking at the SNRM immediately after a resync.
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 17, 2008, 10:24:57 AM
Hey Kitz

Help!!

Fed up waiting for bt to drop target snr so thought I would try DMT tool. Followed the guide but in the special bit the check box for the unlock of experimental area is greyed out and I can't check. Any ideas?

Cheers
Ian

SORRY SORRY  :-[
Plonker alert!!  Just sussed you need to do that before you connect!


Which I have just done and it won't let me adjust anything!!?? (its greyed out)
So I click connect and the 4th & 5th tabs then disappear!! What the heck am I doing wrong??
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on February 17, 2008, 11:42:07 AM
After you checked the option to reveal the experimental area, did you remember to click the Save button?
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 17, 2008, 12:41:35 PM
Hi roseway, Yes I did.

What happens is I start the install and before I connect check the box which warns me of various things and do I want to continue, click yes and then the two extra tabs appear, then I click save/close, they are still there but i am unable to change anything (greyed out). I click connect and they disappear!

Baffled!  ???
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on February 17, 2008, 01:57:46 PM
Hmm.. that's (sort of) what happens if you're using the wrong version of DMT, but if that were the case you wouldn't be able to connect. I admit to being a bit puzzled.
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 17, 2008, 02:42:51 PM
Been reading a few different forums and there has been mention of DMT not working properly with newer firmware versions of other speedtouch routers?
Mine is a 585 with 6.2.29.2 (no mention anywhere of that one)
I got it new from ebay but has tiscali branding (or whatever it is called) but worked no problem when first connected and is still fine.
Could any of that affect DMT tools' ability to work do you think?

I guess I will have to go back to BT again and try again to get target lowered to 12db!

Failing that, just another thought, would resetting router manually every day (or on a timeswitch), say during a quiet time, be of any help to keep up a good sync speed, as it will sync well during quiet time. What I am getting at, is that on the rarer occasion now that it loses connection it is usually once a lot of errors have built up AND at predominantly a noisier time and will then sync at the lower threshold speed which then as you are aware will drop my profile for up to 3 days!
By resyncing every night once my profile is good would that keep the same profile as long as it always syncs within the same profile bracket or above?
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on February 17, 2008, 03:15:40 PM
Quote
Mine is a 585 with 6.2.29.2 (no mention anywhere of that one)
I got it new from ebay but has tiscali branding (or whatever it is called) but worked no problem when first connected and is still fine.
Could any of that affect DMT tools' ability to work do you think?

Yes, that's quite possible, and could well be the explanation.

Quote
Failing that, just another thought, would resetting router manually every day (or on a timeswitch), say during a quiet time, be of any help to keep up a good sync speed...

It wouldn't do any harm, and it might work. The only thing which occurs it might make it more difficult to persuade BT to lower the target margin manually, because the line would still appear to have some instability. Personally, I would try to be patient and let it find its own level as it now is, then see if the automatic processes work as they should and start to lower the target margin.
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 17, 2008, 07:57:58 PM
Yeah that sounds like a plan.
Before I read your reply I thought I would give BT another crack and the guy I spoke to said he would ask wholesale to lower tsnr to 12db. I asked him to call me back to let me know how he got on - which he did! and told me that my initial request (2 weeks ago) had been escalated and was due to be actioned but he asked them when and they 'said' 2 to 3 days!
We shall see....................................................

Cheers for your help  :)
Ian
Title: Re: Very high noise margin drop in afternoon
Post by: Ezzer on February 17, 2008, 08:15:57 PM
Ian, one point, when you get crc,& hec errors quoted, over what time period are the numbers.

When I do a test, I normaly run it for 5 min's. from 1-5mins crc & hec errors can normaly be up to 20, any thing up to 60 isn't anything to worry about, once in three figures then you have a problem.

If interleaving is on then you can multiply this by 10.

RS or FEC errors then up to 14500 is ok, much more than this (again within a 1-5 min time period) then the system is starting to spend more & more effort repairing errors rather than straight up/down loads
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 18, 2008, 12:08:32 AM
Hi Ezzer

Cheers for the input.

To be honest I have not really monitored it over a 5 minute period but I think on average it is well within your figures quoted, been up for 12 hours now since last resync and figures look ok.

FEC Errors (Up/Down): 0 / 260,753
 
CRC Errors (Up/Down): 0 / 2,672
 
HEC Errors (Up/Down): 0 / 2,501

What I was getting at was (and I think I read somewhere on this forum) that once the figures get to a very large amount did the router want to refresh itself so to speak and does so by resyncing? Possibly at a noisier time and then the only way of hitting the higher target snr of 15db it has to do so at a slower sync.

I may be off the mark or misunderstood what I had read as I cannot find the post again!

Anyway fingers crossed once the tsnr is reset to 12db, it should hopefully whenever it resyncs do so within the higher bracket every time.

Ian


P.S. Just been on phone to BT they have told me btw won't reset tsnr as there isn't a fault. Did all the false raising of tsnr because of previous problem and that it wont lower on it's own as I occasionally get a cr*p resync, but they were insistant they could not (would not?) do it!
Just emailed julie foster @bt (internet complaints I think) see what happens now!
Title: Re: Very high noise margin drop in afternoon
Post by: Ezzer on February 18, 2008, 09:01:00 PM
based on 12 hours your errors look ok (thanks to KITZ for letting me know routers do measure this accumitivly)

As for BTw not resetting your target SNR. I think I can see the reason why. This may sound daft . As end user all issues to do with your broadband have to raised via your ISP :-\ Effectively BTw are not permitted to deal with any issues to do with either DSL or PSTN (normal telephony) direct with the end user (you) :-X. And I'm not 100% on this but I don't think they can change this setting without a fault raised against it by the ISP.

It's all to do with the rules setup by offcom to make sure all end users, isp's, sp's are delt with fairly. For instance an Openreach engineer is't permitted to talk directly to an ISP & vica verca :-X

Ofcom, there to protect us :wall:
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 18, 2008, 09:38:47 PM
Hi Ezzer

Yeah I understand that, maybe I wasn't clear my isp is bt who have said they asked btw (I am guessing they have a method of contact) to reset tsnr and bt tell me that btw won't do it? Or maybe the pleb (sorry - 'technical assistant') :D on the helpdesk is just talking to an 'engineer' within bt who is telling her it can't or won't be done? I dunno, maybe I have misunderstood in my haze of frustration, I just want to reach down the phone grab someone by the throat and say look - it can't be that hard - just do it!! :shoot: BT
It seems the simpler the request these days the harder it is to get it done! ???

Anyway as roseway has said it may be just worth sitting back for a while and be patient and see what happens.

Shame I can't get the DMT tool to work and just try for myself a small adjustment or two!

Still, as I write things seem ok, snr margin has crept down to 11.5 from initial 15 - usual 'noisy' time - (just hope it doesn't try to resync at the moment as it will probably not make the present tsnr without dropping sync speed!)

Ian

Title: Re: Very high noise margin drop in afternoon
Post by: Ezzer on February 18, 2008, 09:52:06 PM
Sorry, I should have spotted where you've written BT then BTw ???

Roseways advice is spot on, I think the situaton may change if BTw can see a better SNR margin running consistantly over time. As for the lovely call centre/technical :lol: helpdesk, would you belive me if I were to tell you there's an ISP that's much worse- much much worse :baby:
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 19, 2008, 10:21:18 PM
UNREAL !!!

Got a call tonight from someone else from BT asking how the 'fault' on my line was???!!!

Tried to explain as briefly as possible the situation and that it wasn't a 'fault' and she said she would go to BTw to get the tsnr reset and would get back to me and let me know when it would be done! She did and said the next couple of days it would be reset! Am I in the twilight zone???

Watch this space......................

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 20, 2008, 08:16:05 PM
Well it finally happened at 2 today!! Tsnr was reset to 12db

Trouble is, I think it may be a little noisy as it has dropped connection 4 times since then and reconnected slower each time. The last time it resynced the tsnr had gone back to 15/16. Bad news!!  :( :( :( :( :(

Ah well it was worth a try, will have to accept that maybe the system knows best!!! :-[

Cheers to all you guys and girls for your help along the way - fab forum, will keep on looking as a lot of very interesting and enlightening stuff on offer! ;D

All the best

Ian

Edit: Just did a manual reset and it does still have tsnr of 12!  Weird stuff?
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 21, 2008, 11:06:37 PM
Hi again
Roseway, kitz, or anyone who may have any definitive answer to this one! :)
Now that my tsnr has been reset to 12 I am experiencing higher sync speeds (up to 4480!) but they are dropping out in the evening, reconnecting albiet still at a good speed and with 12db tsnr, then after 3 or 4 resyncs (4200, 4000, 3900) - my snr margin goes a bit up and down but no further down than about 8, it then syncs at a much lower speed (2976) at tsnr 15db, I then do a manual resync and it is a good one (3808) at 12db and it stays like that until the next day in the evening when it drops out and syncs at an even higher speed and then starts dropping again until the above starts over again. Am I to understand this will eventually settle or will I have to go back cap in hand and ask to go back to tsnr 15db? Why won't it stay at the 3808 - I am happy with that, that is the speed I was aiming for, it doesn't need to try and go faster!!
Really sorry to be a pain, but I thought all would be great with the reset!  :(

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 22, 2008, 07:26:24 AM
hmm   its looking like 12dB target margin isnt sufficient to keep your line stable :(

However...  there is an underlying cause to that - why does it need such a high lee-way? 
The line will only drop when there is insufficient margin to maintain the connection...  so whats causing the SNR to drop?
Therefore we are back to something is causing interference ..  which is lowering your SNR lower than the margin.

The 15dB target SNR probably gives your line sufficient margin to stay connected when whatever is causing the interference occurs.....  but you say

>> my snr margin goes a bit up and down but no further down than about 8,

8 should be sufficient to keep your line connected which is what is confusing...

Sorry I cant remember, are you using router stats to log the SNR?  I'm wondering if theres spiking which could be knocking you off line.

Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 22, 2008, 05:03:36 PM
Hi kitz,
Yeah I use router stats and nothing looks out of the ordinary, I had a resync this morning at about 7.50am to 4675!! Highest ever! and it has ticked along all day without a problem and has just resynced at 4256. I have posted a few screen captures (during the night it hardly moves!) I think I will see how it goes over the next few days.

I just checked my profile it is 4 mb!! Cool. Never been to those dizzy heights before. ;D No good if it won't stay there though. I just want it to stay at 3/3.5mb - I am happy with that! I think I need a 13 or 14 tsnr!!??

Sorry about the mish mash of captures - first time  :)

Ian



[attachment deleted by admin]
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 22, 2008, 05:34:16 PM
hmmm  aside from the 8am ish and 4pm ish blips your line looks pretty stable from those graphs.

Looking more and more like possibly something that someone switches on at those times - water immersion / heater / lighting ?
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 22, 2008, 05:54:34 PM
Immersion comes on at about 5 for 1hour (no blips then)
Heating at about 6.30
Couple of lights but then again they are on and off all times of the day!?
There doesn't seem to be anything (in my house at least), maybe neighbours have something, or something else I may have overlooked, but resyncs don't seem to be at any particular time or the same time each day.
It's a shame I can't get the DMT tool to work I may have been able to tweek it a little to keep it stable when there is extra noise. At least it seems for the most part to be resyncing above the 3424 that I wanted (I will keep my fingers crossed that stays that way). It is now just a small annoyance if it does decide not to do so. But I have noticed the profile (since the 2976 sync) has come back up within 24 hours so its not too bad.
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 22, 2008, 06:50:12 PM
Thats damn annoying that DMT isnt working on the 585 due to the new firmware :(

How confident are you about downgrading it?

http://bbs.adslguide.org.uk/showthreaded.php?Cat=&Board=dslrouter&Number=3228436

Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 22, 2008, 08:41:13 PM
mmmm.... not as confident as I would like to be! But at least there is an option should I decide to.
I think I may leave things be for the time being and see what happens over the next week or so. Tell me, will the system adjust itself the other way (i.e. put my tsnr back up to 15) if I get too many resyncs? If so it may be worth attempting the downgrade and tweaking to avoid that happening.

Cheers

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: kitz on February 22, 2008, 08:47:08 PM
In theory it "should do"...  generally it tends to increase faster than a decrease.

Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 23, 2008, 02:55:30 PM
Hey kitz
Sorry just one more quick 'theory' - I have been connected @ 4608 since the last drop that put my profile back to 2.5mb (about 7hours) and it has been almost a straight line on the routerstats +/- 1db at 12db now and again. Is that because the system is working at the lower profile and will not start being less stable until the profile is upped in relation to the current 4608 sync speed?
Ian
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on February 23, 2008, 03:16:46 PM
No, the IP profile has no effect on your connection, it's just a limit on the download speed. If you're not seeing the noise spikes now, your best option is to cross your fingers and pray it stays that way. :)
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 23, 2008, 04:49:57 PM
Hey Roseway
Thats the kind of theories I like!  ;D

Just noticed it has reconnected at 4265 at almost the same time as it did yesterday (2mins difference) so maybe kitz has a point about external affects - something I am unaware of maybe happening at that time to affect it. Or maybe that is the set time for the system to 'check' things? Grasping now though I think  :D

I think I will hang onto the fingers crossed idea for now though :)

Cheers
Ian
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on February 29, 2008, 09:35:30 PM
Hi Roseway, kitz and all you other most helpful folks,
I may be tempting fate with this post, but things seem to be pretty good at present. Still connected at 4265, profile of 3.5mb  ;D
Had a few drops but has resynced above 4000 for nearly a week now! (Maybe after a TSNR reset the system retrains itself?) - Anyway - Well pleased ;D
Hell, if that hasn't put a jinx on it, I may be finally OK -  'pray & fingers crossed' ! ::)

I got a call from BT chairmans office with regard to all my communications (2 really long letters, 3 emails and countless phone calls to the helplines) apologising for the inconvenience, and the fact my letters were mislaid and since been found! They made no excuses and were really apologetic and are refunding 3 months bb subscription.  :)

After nearly 3 months of perseverence, hopefully I can finally put this to bed!

So a message to anyone having problems, if you can contain your rage and frustration, keep badgering along it may be worth it in the end!?  ???

All the best

Ian
Title: Re: Very high noise margin drop in afternoon
Post by: roseway on February 29, 2008, 10:36:40 PM
I'll be crossing my fingers for you too (http://www.emotionless.co.uk/emotes/a/laugh7.gif)
Title: Re: Very high noise margin drop in afternoon
Post by: mr_chris on March 01, 2008, 01:14:01 AM
Quote
if you can contain your rage and frustration

You've hit the nail on the head there... that's the key to successfully dealing with a lot of problems, not just with broadband, but in life as well!

Fingers crossed .. and well done for remaining calm about it!!
Title: Re: Very high noise margin drop in afternoon
Post by: Ian1261 on March 01, 2008, 08:37:05 PM
Cheers Guys :drink: