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[jaypeecee]

Hi Folks,

My IP Profile is currently set at 1000 kbps and my actual throughput (as measured on speedtester.bt.com) is 938 kbps. DSL connection rate is 1152 kbps (DOWN-STREAM) and 448 kbps (UP-STREAM). Normally, my download speed is just under 2000 kbps and upload speed is approx. 400 kbps. I should point out that, just over ten days ago, I had cause to unplug my router/modem from the ADSL line for half an hour. My modem/router is powered on 24/7. My ISP is BT Broadband.

Over the last few days, I keep checking my IP profile but it's stuck on 1000 kbps. I contacted the Indian call centre but, as usual, it was a complete waste of time. Would have got more satisfaction ordering an Indian take-away!

So, I've waited the prescribed ten days from re-connection but to no avail. Does anyone have any idea when I can expect my connection speed to be back to where it used to be?

Thanks.

JPC

[roseway]

If your connection speed is 1152 kbps then your profile is correctly set to 1000. It won't increase until you reconnect at a higher speed, and after that it can take between a few hours and five days for the IP profile to rise.

Disconnecting your router for half an hour is no problem, and there isn't any 'prescribed ten days' for it to recover afterwards. I suggest that you reboot the router and see if it connects at a higher speed, and if not then copy your router stats here so we can see if there is anything strange in the figures.

[jaypeecee]

Roseway,

Thanks for your reply.

I re-booted my modem/router having left it off for 5 minutes. Then ran the speedtester.bt.com. IP profile hasn't changed. Couldn't do a copy/paste on my router stats but here are the figures:
Line Attn: 56dB (down), 15.5dB (up)
Noise Margin: 13dB (down), 19dB (up)
DSL conn. rate: 1184 kbps (down), 448 kbps (up)
BTW, router is a Netgear DG834G version 3.
On the basis that the connection speed has only increased by a mere 32 kbps, I guess the IP profile will remain at 1000 kbps. I'm interested in your comment that there isn't any 'prescribed ten days' as I was under the (obviously wrong) impression that a period of ten days had to be allowed in order for the adaptive ADSL to do its thing. BTW, I am an Electronics Engineer - just don't know much about ADSL!

So, where do I go from here - any suggestions would be appreciated.

JPC

[roseway]

It looks as though your target noise margin may have increased, which would account for a reduction in connection speed. The target noise margin is set automatically in the exchange, and it gets increased to improve stability if the connection is seen to be unstable. This could have been the result of a period of frequent connection drops at some time in the recent past.

The only way to know what your target noise margin is, is to read the router stats immediately after a reboot. The downstream noise margin at that time should be close to the target. Don't bother checking your IP profile, because it won't increase immediately even if you do connect at a higher speed.

You do have a rather long line, so it's very much in your interest to do all you can to make sure that your own setup is a good as possible. Have a read of these pages to get some ideas for doing this.

[jaypeecee]

Hi Roseway,

The crux of my concern is that I used to get just under 2000 kbps download speed and this figure has now halved. My internal house wiring hasn't changed, the microfilter is the same and the router is the same. Indeed, everything is the same. My suspicion is that the speed reduction has been caused by all the wet weather we have had of recent. It does seem to correlate and I do vaguely recall something similar happening in the past when we had prolonged periods of rain.

JPC

[roseway]

It's certainly not unknown for wet weather to affect telephone lines, but there's usually some noise on the telephone at the same time. If that happens then you can report it to BT as a voice fault.

[kitz]

The other explanation I can think of is there has been (or at least in this part of the country) a lot of thunderstorms over the past few weeks.
Thunder and Lightning can cause havoc with adsl and in particular the SNR.  Im on a very short line with all underground cabling but it can still cause fluctuations and huge error counts with my own line

It is possible that the storms have introduced some instability on your line, and the DLM has reacted by increasing your Target SNR.
Its a higher Target SNR thats more than likely keeping your sync speed down now.  The theory is that the target SNR should lower again if your line remains stable for a period of time (a few weeks)

[jaypeecee]

Thanks, guys. I really appreciate your feedback.

I need to get to grips with disconnections carried out by me. I was under the impression that if I interrupt the ADSL signal, then the exchange will automatically drop the sync speed. And, having done this, there will then be a ten-day delay before the sync speed climbs back to where it was before the interruption. Is this incorrect? Roseway, when you say "This could have been the result of a period of frequent connection drops at some time in the recent past", I have had no connection drops other than the brief interruptions that I've carried out.

Kitz, it is the case that there have been a few storms in Berkshire over the last few weeks. So, I guess I'll just have to wait a few weeks in the hope that my sync speed will increase again.

JPC

[kitz]

>> I was under the impression that if I interrupt the ADSL signal, then the exchange will automatically drop the sync speed.

The line will always connect at the best speed it can.  The better your SNR Margin, then the higher the connection speed will be. 
However theres also something called the Target SNR - this is the figure set on the DLM that it thinks is best for your line.  Therefore if your target SNR is set at 6/9/12/15db, then the DSLAM and your router will negotiate the highest speed where your SNR Margin is 6/9/12/15 dB.

>> there will then be a ten-day delay before the sync speed climbs back to where it was before the interruption.

No sync speed can and often does change each and everytime you connect.
The 10 day period related to the "training stage" when you very first connect to adsl.
- See How dslmax works


>> "This could have been the result of a period of frequent connection drops at some time in the recent past", I have had no connection drops other than the brief interruptions that I've carried out.

Too many disconnections (by yourself) can often fool the DLM into thinking that its due to instability, and it will raise your target SNR. :/

[mr_chris]

Too many disconnections (by yourself) can often fool the DLM into thinking that its due to instability, and it will raise your target SNR. :/

I can testify to that - I have been there, done that, got the T-shirt.. and it doesn't take a great many number of disconnections to do it either.

[Ezzer]

I know 10 drops of sync

(is that correct grammar ? ah well the number of times butter fingers here has posted and then realised now haow did i spool it like dat !)

would cause the dlm to sit up and take a strong look at the line

(assuming there's no current fault pending beyond bt wholesale which alows us to keep going in the network & rechecking without causing undue detriment to the service)

Although I don't know if there is another perameter lurking there like 5 in 15-20 mins or the like
(or the like" I know of someone who would flip at my using that expression)

[jaypeecee]

Hi Guys,

For the last few days, my IP Profile has remained at 1000 kbps. However, today it has taken an almighty dive! Using speedtester.bt.com, my DSL connection rate is 160 kbps (DOWN-STREAM) and 448 kbps (UP-STREAM). My IP Profile is 135 kbps and actual throughput is 120 kbps. I also checked my router stats and the noise margin has risen to 18/19 dB (DOWN) and 19dB (UP). My DOWN-STREAM noise margin is normally 12dB. There have been no disconnections since I re-booted the router six days ago.

What on earth is going on? I need your help, guys!

Incidentally, I previously failed to mention that I have a surge arrestor connected between the BT wall socket and the microfilter - my apologies. Having said that, I previously bypassed it and it made no difference whatsoever to the connection speed. The surge arrestor is made by APC and it's a PTel2.

Thanks in advance.

JPC

[roseway]

Something has happened to cause your router to reconnect at a much lower speed (160 kbps). Whatever it was seems to have been a temporary event, so you're now seeing a high noise margin. If you reboot your router it will probably connect at a higher speed again, but the problem is quite likely to recur at some point.

There are numerous possibilities for the cause of this problem. Can I suggest that you install Routerstats and leave it running to monitor the noise margin over time. This may well give us some clues as to the cause. Apart from that, it's definitely worth making sure that your own setup is as good as possible, and a read of these pages may help you to do this.

[themadprofessor]

I note that your Netgear DG834 v3 has the TI AR7 chipset which is well known for not handling noisy lines very well.

If you could either beg or borrow a router with a Broadcom chipset you would eliminate your Router as potentially being the cause of the issue.

The Netgear DG834 v4 has a Broadcom chip set as has the 834GT, 834PN, and 834N and many others.

If you borrow another router and try that. You do not need to alter the log in if it is a borrowed one as all you need to see is the sync rate.

If this one syncs at the same rate as your Netgear then it is highly likely that the fall in your sync rate is due to some sort of cabling issue either in your house or between you and the exchange.

You can eliminate your house wiring as a cause by plugging your router into the master socket rear socket found if you have an NTE5 behind the front removable cover.
The difference between the attenuation should be less than 0.5 dB between the usual arrangement and plugging direct into the rear of the socket.

Whilst you are in there you could visually confirm that there is no extension wiring connected to the incoming BT terminals "a" and "b". If there were then it would be (a) illegal wiring and (b) badly affecting your ADSL connection

I hope this helps

Chris

[jaypeecee]

Chris,

I bought the Netgear DG834G v3 on the recommendation of the Kitz site and I've been using it very successfully for almost a year. Ironically, when I first started using it, it was the best thing since sliced bread. The disconnections that I used to see with my BT Voyager 2091 were a thing of the past and my download speeds increased dramatically. I still don't have a problem with disconnections. My problem now is download speed.

I tried plugging the router into the master socket and there was no measurable improvement.

Having re-booted my router yesterday, my Rx Sync has increased to 1152 kbps, Rx Noise is 11/12dB (normal for my line) but my IP Profile is still a mere 135 kbps - I'm hoping that this figure will increase in the near future. Does anybody know when I'm likely to see an increase? I've also installed RouterStats v4.3, as suggested by roseway.

Please keep the suggestions and assistance coming. I need to crack this one!

Thanks.

JPC