Kitz Forum
Broadband Related => ADSL Issues => Topic started by: jaypeecee on August 20, 2008, 01:55:13 PM
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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
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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.
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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
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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 (http://www.kitz.co.uk/adsl/socket.htm) to get some ideas for doing this.
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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
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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.
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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)
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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
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>> 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 (http://www.kitz.co.uk/adsl/linestats.htm) 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 (http://www.kitz.co.uk/adsl/maxdsl2.htm)
>> "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. :/
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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.
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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)
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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
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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 (http://www.vwlowen.co.uk/internet/files.htm) 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 (http://www.kitz.co.uk/adsl/lowSNR.htm) may help you to do this.
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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
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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
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at 135kbps you have a "throttle back" where some horrible noise issues has hit the line and the dlm has slowed things down to maintain a connection (this is with speeds of about 135 or 248 kbps as opposed to any other slower than expected speeds.
I know with a dsl fault reported on the line then any stable stats with no anomolies should clear the throttle back within 24 hours. It can some times be nudged manualy via bt wholesale. If your sure your stats are stable then try asking your isp to get BT wholesale to take a look at the throttle back, if it hasn't cleared with a stable connection.
It's like traveling on the motorway in a car when you feel some black ice, so although you can theoreticaly do 70mph you slow down to 15-20 until your confident the conditions are ok again as it's better than risking it and comming off the road completely
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The Netgear range of routers are certainly above average in performance and I have a DG834PN. It outperforms a Thomson Speedtouch 585 that I bought from eBay as an experiment.
I have also got a DG834 v3 that I borrowed from my son after he went onto cable. I found it considerably less stable on my line than the DG834PN. I was finding that the noise on my line was causing continuous resyncs that just caused lower and lower speeds. Once I replaced it with the DG834PN, the speed remained constant at 7616Kbps.
I was converted!
Regarding your profile. I have been told that the software that controls the Profiles has been altered. If a one off event causes a resync to a low speed, and then after the event has passed the sync doubles or trebles, then allegedly the profile should recover in 75 minutes. However if the profile increases by 10% increments then the profile change can take up to ten days to take effect. Apparently the speed with which the profile changes also depends on how busy the supervisory software in that exchange is, and a change that should alter in 75 minutes can still take up to 3 days to take effect.
Now bear in mind that this is all hearsay as as far as I know none of these "facts" are actually published by BT or written down anywhere!!
Chris
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Hi Guys,
Well, I'm still waiting for something positive to happen. IP Profile is still 135 kbps and Rx Sync is still 1152 kbps - these figures have not changed for two days now. So, according to themadprofessor (Chris), I may still need to wait a good few days before I see any changes. That gives me a problem.
I ran RouterStats from 1300h to 1900h yesterday. Rx Noise was 12dB +/-1dB with the occasional peak up to 15dB. I've also had RouterStats running this morning for just over an hour and the picture was much the same. I have had no disconnects. The peaks up to 15dB are unusual in that I never used to see these when I had cause to use RouterStats about six months ago.
Ezzer, you suggest talking to my ISP to get BT Wholesale to take a look at the throttle back. The trouble is that my ISP is BT Broadband and that means contacting their overseas call centre, which fills me with dread. I know now that it will be a complete waste of time. Do you know of any way by which I can bypass their call centre and contact BT Wholesale directly?
Thanks for all your help.
JPC
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Sorry the rules set by ofcom you as the end user have to go via your sp/isp. There's no direct contact with wholesale or openreach as your not a customer of theirs the sp/isp is.
I understand what your saying about the call center as I hear about it all day every working day (and belive it or not there are 2 isp's with a worse reputation)
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Thanks, Ezzer. Throughout this thread, there have been references to re-booting my router, which may cause my router to re-sync at a higher speed and, indeed, this appears to be the case. I presume that this is the only way of getting any router to re-sync i.e. by re-booting it. In other words, would it ever re-sync if the router was never re-booted? And then my next question is - in order to re-boot, a router has to be turned off and then turned on again. So, how long should it be turned off for or doesn't it matter? And, finally, I thought disconnects were bad news as far as ADSL is concerned - this can result in the all-important IP Profile being lowered. Doesn't that mean that it's unwise to re-boot a router? [In asking this, I'm considering a re-boot to be a type of disconnect].
Sorry to bombard everyone with all these questions but I'm really trying to get to grips with ADSL and, at the moment, I'm just a tad confused.
Thanks,
JPC
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With many routers you can do a restart from the web interface, and I guess that this would be the best way to do it as it would be a proper shutdown and not an abrupt loss of power. However, if yours doesn't have the capability to do this, then power off / wait ten seconds / power on would do it. So long as you only do this infrequently it shouldn't affect your IP profile.
If you don't force a restart, then it will almost certainly happen eventually but it could take several weeks. There's no mechanism in ADSL Max for the router to automatically connect at a higher speed when conditions improve, so it will only happen as a result of a glitch or a degraded signal.
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Hi JPC,
Kitz's site contains all the info you need for you to understand how adslmax works - you just have to settle down and start reading ;)
I've had my own go at explaining things here: www.hmmm.ip3.co.uk/adslmax
If you haven't already, try your 'test' socket - behind the removable faceplate.
I improved my connection (line att. 51db) massively by switching from a Netgear (AR7 chipset version) to a Speedtouch.
Got to go, dinner's ready :)
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I understand what your saying about the call center as I hear about to all day every working day (and belive it or not there are 2 isp's with a worse reputation)
Yes I should know, I am with one of those ISPs. No names mentioned....Tiscali! :-\
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I understand what your saying about the call center as I hear about to all day every working day (and belive it or not there are 2 isp's with a worse reputation)
Yes I should know, I am with one of those ISPs. No names mentioned....Tiscali! :-\
You may say that, I couldn't possibly comment. :-X
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Hi JPC,
Kitz's site contains all the info you need for you to understand how adslmax works - you just have to settle down and start reading ;)
Over the last few months, I've read a great deal of Kitz' site and learned a lot about ADSL. Indeed, I think it's the best ADSL site on the web. It's just that I needed clarification on a few issues, which the good people on this forum have now provided.
Anyway, I can now report that things are improving. Today, my DSL connection rate is 1152 kbps (DOWN-STREAM) and 448 kbps (UP-STREAM). My IP Profile is a much more respectable 1000 kbps, actual throughput was 921 kbps. As I said at the outset, I used to see download speeds of 1900 kbps so I've got a way to go yet but at least I'm heading in the right direction!
Thanks to everyone for all your valuable help.
JPC
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Hi JPC
It would appear that atm something is causing some instability on your line and causing it to sync at a very low speed, as others have mentioned unfortunately once things have cleared, then the router doesnt automatically sync back up again at the higher rate - it only adjusts downwards :/
It could be storms, or it could even be a fault developing on your line.. one thing that is clear though is that its the disconnections that have caused the DLM to increase your target SNR, which in turn is what now stops you from syncing at the previous higher rate. If it was a one off then I'd normally suggest you contact your ISP and request that they ask BTw to reduce your target back down again.. but right now if I've understood correctly and youve had more than one low sync, then this would be a bit of a waste of time if it could do it again in the near future. However if it was only one low sync, then its certain worthwhile approaching your ISP to ask.
Continuing to monitor with router stats wont harm either.. I'm not sure if youre aware, (sorry if you are) but you can change the settings so that it will automatically log and send each days readings to a separate file.
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Hi Folks,
I'm getting sick of this ADSL lark! Yes, you guessed it - things have got worse again. To be precise, my DSL connection rate is 1088 kbps (down), 448 kbps (up). IP profile is down from 1000 kbps to 750 kbps and actual throughput is 694 kbps. It may have been caused by a minor storm on Sunday (31 Aug) but I can't be sure. According to RouterStats, the WAN has been 'up' for 194 hours - in other words, there have been no disconnections since I last re-booted my router. Unfortunately, I am unable to run RouterStats continuously as it causes problems with my PC.
I discovered a 'phone number - 0800 707 6044 - on another forum. Apparently, it's possible to 'phone this number to check if your ADSL line is being throttled. Does this number ring a bell (pun intended) with anyone? I guess there's no point in re-booting my router at the moment until such time as my IP profile has climbed again to 1000 kbps?
JPC
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If your connection speed is 1088 then your IP profile is going to stay where it is until you do reboot your router (or it reconnects for some other reason). If the connection speed is lower than it was, then the router must have reconnected recently, despite what Routerstats says.
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As roseway has pointing out you are going to need a higher sync for your IP Profile to move up. You need 1152+ to get a 1000 profile.
As Kitz has mentioned, it looks as if your 'target SNR' has been raised due to instability in the past which has reduced your sync. For this to improve your line needs to run stable for 14 days (or more) or get it manually reduced (which BT will only do if it looks stable) - and as your IP Profile has been reduced it doesn't appear to be.
It's a shame you can't run RouterStats continuously - what problems does it cause for you?
The number you quote appears to be for BT Support...
As I mentioned previously - changing from a Netgear (with AR7 chipset like yours) to a Speedtouch 585v6 (with a Broadcom chipset) on a long line (50+ attenuation) sorted my problems out...
EDIT: Just to add I see you've mentioned a couple of times your 'throughput' is always slightly less than your IP Profile - don't worry about this, it's normal - all down to "overheads"!
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Just to confirm, I was advised that
The FUP team: 0800 707 6044
Customer support: 0845 600 7030
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It's a shame you can't run RouterStats continuously - what problems does it cause for you?
b4dger,
I appear to have licked the problem with RouterStats and it's now running continuously. I've also set it up to capture graphs of Rx Noise and RX Sync constantly. I'll run it like that for a few days then check the graphs for any unusual behaviour. If all seems well, I'll then delete the graphs as they use up approx. 5MB hard disk space per day. Needless to say, my PC is powered up 24/7.
JPC
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Hi Folks,
I thought it might be useful to post one of the graph captures from earlier today (see attached). Ignore the dips to 0dB at 12:32 and 13:02 - these are caused by RouterStats logging in to my router every 30 minutes and I'm not sure if I can change this. However, the other dips are for real. I must stress that Rx Noise is not always like the example attached. A lot of the time, it's pretty stable at 12dB +/- 1dB. What's interesting is that, despite these dips down to 2/3dB, the Netgear DG834G v3 does not lose connection!
Any comments?
JPC
[attachment deleted by admin]
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Hmm... some sort of impulse noise.
Fridge/Freezer? Some other sort of thermostat device?
Those dips will be why your target SNR has increased.
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Hi Folks,
Me again! Let me first apologize to the forum users as this thread is dragging out a bit. However, I have made significant progress and I thought others may be interested in knowing how I've improved my ADSL connection. Basically, three days ago, I removed the ringer wires from the master socket (on my side, not the BT side) and also removed the same wires from the one and only extension socket that feeds my modem/router. On re-booting my router, Rx Sync was 2144 kbps. Today, Rx Sync is still 2144 kbps and my IP Profile has increased to 1750 kbps. Rx Noise normally fluctuates between 12dB and 15dB. Late at night, however, Rx Noise is all over the place but Rx Sync holds steady at 2144 kbps. I have attached a RouterStats plot from last night and would really appreciate any comments. I thought the large fluctuations might be caused by a neighbour who is using the same channel as me. I use some software called WirelessMon and I was able to see that my neighbour's router signal last night was similar to my own. However, his signal is the same this morning but the Rx Noise is back to its normal 12dB - 15dB.
All comments greatly appreciated.
JPC
[attachment deleted by admin]
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Your SNR fluctuations are now within a 8dB variance
Its certainly less than previous and the graph now looks a little bit more normal for a reasonably long line ... and at least the impulse spikes have disappeared which is something at least.
Obviously there is still some noise there, but those are now within normal parameters for some longer lines, and its good that your router is holding on to that 2144 sync and your IPprofile increasing.
Its still not perfect though because of the noise fluctuations, but is considerably better than previous.
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Hi Kitz,
Thanks for the reply. Can you explain why the overall shape of the most recent RouterStats graph is so different from my previous attachment? What I've noticed is that, during the hours of daylight, the Rx Noise graph is essentially a straight line with the occasional dip or peak. However, at night time, the graph shows the Rx Noise drifting apparently at random. The daytime graphs and night time graphs couldn't be more different. Why should this be the case? I don't believe it's related to the number of other active networks in the vicinity - WirelessMon shows an equal number of networks active during the day and at night. Indeed, like myself, it's clear that most people leave their routers on 24/7.
JPC
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That interference is nothing to do with wireless networks - they use much, much higher frequencies. It's quite normal for interference to increase at night for several reasons, and the last graph shows the sort of random variations that you're quite likely to get on a long line, from AM radio transmitters, street lights, and so on.
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roseway,
Many thanks for answering my question. I'll crawl back into my shell now!
JPC
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I didn't mean to shoot you down :-[
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roseway,
No worries - I didn't interpret your reply as shooting me down. Not at all. My reference to crawling back into my shell was just my way of saying that I'd exhausted my list of questions and, as such, I was winding up the thread that I had started. In hindsight, I could have worded it better.
Anyway, thanks to everyone for all your help.
JPC
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yw JPC
Sorry that your line still isnt perfect. It does still have a lot of fluctuations, and although the culprit of the nasty spikes now seems to have disappeared and things are looking a bit better. The fluctuations you are now seeing are what would be considered in a normal fluctuation range by BT.
Tracking down the source of noise is very hard and I can understand that it is so frustrating not knowing what it is :/