Kitz Forum
Broadband Related => ADSL Issues => Topic started by: duckson on December 30, 2009, 11:13:24 PM
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Evening,
Can any of you experts cast your eyes over the following router stat graphs and give me an idea if you've seen anything like this before:-
http://www.duckworth.myzen.co.uk/router/Netgear/ (http://www.duckworth.myzen.co.uk/router/Netgear/)
Note that the connection had been fine for a few years at 8128kbps, this has started happening over the past 4 weeks or so (7150 profile to a 4000 profile the other week, now at a 5000 profile). I have a solid setup with ADSLNation faceplate and ADSLNation "PRO" ADSL cable but have tried 3 other filters, 4 other ADSL cables and 2 other routers to the current Netgear DG834GT i'm using with no change to the results, i am confident its not my side of things at fault!
I have also tried powering down alot of household electrics with no success and have tried the stereo at mid 600khz checking for REIN....nothing found that i can tell.
Strange thing with the fault is that if i reboot the router it will sync at mid 7000kbps's, noise margin will be holding tight to 9db (BT put it up from 6db recently) but then minutes or a few hours later i will get a very large noise spike in the region of 15db which takes the noise margin well into the negative and forces a resync. If the router ends up resyncing at around 6000kbps with a 14/15db noise margin i will not get a massive noise spike again but i will get 5/6db spikes on occasion as can be seen in the above graphs. I dont see 5/6db noise spikes when i'm connected at 9db, they are always large spikes causing the resync.....any ideas why???
The noise spikes dont appear to be at a set interval though they are usually 1-2 hours apart and happen mostly through the night but have recently started occuring during the day as well.
I have logged the fault with Zen who are looking into it but i'm not holding my breath and will seriously consider leaving them if they try and fob me off saying its "normal"....i aint paying a cost premium for nothing!
Has anyone seen this before or have an idea what could be the cause? I'm pinning my hopes on faulty BT equipment at the exchange...
Many thanks and Happy New Year.
Stu
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Hi Stu,
It is perhaps unwise to postulate that there is no local problem. We have recently seen different problems solved by the replacement of a thermostat and an ADSL Nation faceplate.
Modems do sometimes become unreliable. It might be better to start from first principles; use the test socket with a different filter, perhaps a different modem, keep Zen informed etc.
Kind regards,
Walter
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... The noise spikes dont appear to be at a set interval though they are usually 1-2 hours apart and happen mostly through the night but have recently started occuring during the day as well.
I have logged the fault with Zen who are looking into it but i'm not holding my breath and will seriously consider leaving them if they try and fob me off saying its "normal"....i aint paying a cost premium for nothing!
...
G'Day Stu,
Its NOT Normal. Can you PM your fault ref please and any issues you have with the person dealing with the fault. The noise spikes could be related to the weather but by the sounds of things you may have a break in a cable.
Leo
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Walter - I'm using a completely different setup to what i started out with. Gone from an ADSLNation faceplate with ADSLNation PRO cable to a 3COM Officeconnect rotuer to ADSLNation XF-1e filter in the test port with a standard modem cable and a Netgear DG834GT router. Zen are looking into it, i have also tested from my parents house who are with Zen and on the same exchange and about 200 yards nearer the exchange and the rotuerstat graphs dont show the same problem.
Leo - PM sent.
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BT now booked for Saturday....fingers crossed it proves to be straight forward.
I've run DMT tool and got the following results:-
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2Fdmt20091231_1308.png&hash=994f59ac4d025f7e007591bc1181283c8f36adcd)
Not entirely sure what i'm looking for but does this look "normal" or not, it seems to me to be showing SNR spikes although routerstats didnt show anything at the time, its been holding mid 14db's since the last 5/6db spike at 9.20am?
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Hi
quote : noise margin will be holding tight to 9db (BT put it up from 6db recently) but then minutes or a few hours later
BT do not reset Target SNR margin this is part of the negotiation between your router and the DSLAM at the exchange .
quote "If the router ends up resyncing at around 6000kbps with a 14/15db noise margin
ad your latest DMT show SNR margin at 14.4db
This suggests that your targrt SNR is now over 12db maybe 15 . It seems that you have some problem with either your connection to the exchange or some serious noise being generated .This has coused your increase in the target SNRM and so the reduction in synch speed .
see this link (http://www.kitz.co.uk/adsl/linestats_explanation.htm)
quote I have logged the fault with Zen who are looking into it but i'm not holding my breath and will seriously consider leaving them if they try and fob me off saying its "normal"
personally I have never found Zen to be anything but professional. Have you taken up
Azzaka offer ?
regards jeff
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By BT putting it up i meant "BT's equipment". :)
Yes Leo has sorted it for me, BT coming out on Saturday morning.....up to now i have no complaints with Zen, very good service, i even got my parents with Zen as all has been good up to now.
I havent resynced in a couple of days (since last drop on graph below) but when i have been resyncing before that from being sat at the same 5000/6000kbps and a 14/15db noise margin it resyncs at low/mid 7000kbps's and the noise margin is 9db give or take 0.5db. Over minutes or hours it will drop and resync at least once maybe twice and then sit at 5000/6000kbps and a 14/15db noise margin. Is this not normal then? Should it be trying to hit 9db noise margin even if it drops it at this noise margin?
For example:-
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2009Dec29-1656.jpg&hash=7b581f59c7daf2fe3078d142b78e9ca87d36a6df)
Note the massive noise spikes only occur when my nosie margin is around 9db for some odd reason, at 14/15db it doesnt spike that much "only" a 5/6db loss.
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Hi
Can you do a bt speed test (http://www.speedtester.bt.com/). This will give your profile
It does seem to be behaving in a very odd fashion .The only thing I can think of is that when it resynchs ,after the spike the noise is still there so the synch rate is dropped until you achieve stability . The odd thing is that the snr is then so high ,its as if the noise causing the problem has gone . Have you been tweaking the target SNR margin at all?
Regards Jeff
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No tweaking from me! I've just left it as is, never tweaked it, although now having a DG834GT i could do that if i flashed it with DGteam firmware.
Results:-
Download speed achieved during the test was - 4363 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :5984 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 5000 Kbps
Although i can also get the IP Profile from my Zen customer portal...very handy. It also lists the profile changes and any noise margin changes that have occured.
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Hi again Stu,
Do be aware that the data Zen provide is only what BT transmit some time in the future. It can lag by many hours so the safer solution is to grind on with the BT speed test once in every three hours.
Happy New Year,
Walter
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Anyone know what/if the following DMT run is good/bad/indifferent? Obviously the massive 15db noise spike at 16:09 disconnected me and i resynced at 1000kbps less but with a ~4db rise in noise margin.
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2Fdmt20100101_2005.png&hash=7e26cbab2968608ee4ac38e058cc2245eb2bd6ea)
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BT man has been and found nothing, only tested from my end...used the Hawk as well as the standard laptop/modem and said the line to him appears fine. I thought it would as i dont often get spikes during the day, if he had turned up before 9am and connected for 30-45mins he'd of seen the margin drop. Then again he did say it wouldnt give them much to go on even then.... ::)
He did say it could be one of those ones that goes back and forth a few times until they find something and they cant (wont) do anything in the exchange or anywhere else cus they didnt find anything today and might even make it worse if they fiddle with the line. :(
He did say that Zen would have to request a change in the exchange.
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Hi Stu,
Not unsurprising when you observe the frequency of the drops. I suspect you're going to have to record Routerstats and log every & date time that a drop happens. Zen then have some information from the end user demonstrating the problem so that BT O can be persuaded that there is a problem to be solved.
Kind regards,
Walter
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Not long after he left i reconnected and have been out the house since...come back to this (i reconnected the router at 11:00, 3 drops in an hour and it even tried to sync me to a sub 7db noise margin though my profile is 9db??? this gave me the 8128kbps sync i've always had until now!):-
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2F020110-1445.jpg&hash=8e62768618dba46cadfea89de1bf5c52026ebdb2)
And DMT which i ran after i plugged the router back in:-
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2Fdmt20100102_1505.png&hash=a376895d928a4dacdecb73a8ae4734f2760f4db1)
It says i am on Fast Path as well, odd because i've been on Interleaved for ever!!! Since i've been on ADSLMax i've been on Interleaved and that was mid 2006.
Has the BT bod been messing at the exchange do you think, he said there was nothing more he could do at this time?
Any other comments? :'(
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HI
Just don't know what to make of these results . Just surprised that with these drop outs your synch is so good .Maybe the BT guy did do something ?. Cannot see how one resynch would have gone back to default 6db and synch of 8128kbps, considering the problems you are having .
Regards Jeff.
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Yep weird alright.
Maybe the exchange equip. is going wonky. ???
At least it shows my line can run a sync of 8128kbps with a decent noise margin (7db give or take)....for a short time in this instance anyway!
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I found that my connection recently changed from interleaved to fast path without me requesting it. Fortunately, the connection is now fast and stable (for the first time since summer 2006 but how long will it last?) and I have asked my ISP that it be left as it is, i.e. fast path. I could believe that changes happen at BT's whim and since I am not advised that a change has been made, I am mystified when the behaviour of the connection suddenly changes, usually for the worse. No wonder that people are hostile towards ADSL service providers and BT in particular.
I suppose it is impractical for BT advise the ISP (for customer information) when they have changed something that will affect the performance of a connection.
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It certainly looks as if Zen will have to be involved. If you e-mail your results to:-
support@zen.co.uk
quoting your fault reference number and then call them, they can see what you are complaining about.
Clutching at straws, you might just check you have good modem power and cable connections.
Kind regards,
Walter
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(seen your post as i'm writing this Walter, i think everything is ok with me on the PSU/cable front if you read below (not withstanding i've tried 3 routers and 4 ADSL cables and filters...)).
Well confusion reigns. :o
Lost PPP not long ago and it took 15-20mins for me to log into Zen. I also lost sync, got it back (at 8128kbps / ~6.5db SNRM!!), wouldnt connect to Zen for a 14 minutes (LCP Down) and then its up again now. Wonder how long 8128kbps will hold. Another thing, logged into the Zen portal and from 12:34pm today i have a 7150 profile again! I think Mr BT man has been messing about, reset me to a 6db margin and put me on Fast Path?!
On top of this i set my parents up running routerstats this afternoon with one of my spare routers, a Draytek 2800G. I phoned them when i couldnt get any net access just now and they confirmed they couldnt either....around the same time their sync dropped as well and they couldnt connect to Zen thereafter for a while. They are on the same exchange and live on the same road as me a few hundred yards away. I've got their graphs / Log to prove this....all a bit coincidental dont you think?
Also my sister in law and mother in law (also on the same exchange) said they had sync drops today (this afternoon sometime), Mother in law is on BT but i'm not sure what the Sister in law is on now (was Tiscali but she changed to something else cus her boyfriend gets free net access through work).
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Well it lasted an hour and a 1/2 then dropped sync (large noise spike) and reconnected at 6976kbps / 10-11db noise margin. :(
Up until then it was quite a smooth noise margin keeping north of 6db even.
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Hi Stu,
With the information you have, including the phone numbers from your relations, Zen should be able to say there is a probable faulty DSLAM (or possibly other equipment) in the exchange.
Nearby houses could perhaps be using the same cable so might be susceptible to a common noise spike but it seems highly unlikely that four different services would be all using one cable.
Zen will almost certainly be using BT Wholesale services as will BT retail. It's only LLU providers who would be using non-BT equipment.
Good luck with Zen and BT,
Kind regards,
Walter
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Since 8pm last night (i disconnected at 23:45 to 23:54):-
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan03-1009.jpg&hash=0bc26c365dbf4242bb9823ec8d4784bb6bfc93b9)
It appears i'm maybe back on the 10 day training possibly, my Zen portal page shows the MSR @ 288 and FTR @ 288 which changed last night just before midnight. Previous values were set in March 2007.
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I have another BT engineer booked for this Friday and hopefully they are going to do a 2hr extended test from the exchange end.
Zen had to push it up to "BTw Interventions" team to get this done as they wont take my logs/graphs as evidence that something isnt "right". ::)
Aside from this i've held sync at 7008kbps for 2 days now, its lower than my normal 8128kbps as the noise margin needs to be 10-11db so the spikes dont drop the connection. If i resync during daytime at least i reconnect at 8128kbps and ~7db for a while (couple of hours if i'm lucky).
Does the Router log for the 48 hours look normal or do i have a large amount of errors? (ADSLNation faceplate, ADSLNation "PRO" ADSL cable, 2 x standard extension phone lines to 2 Sky boxes and house phone plugged into front of face plate).
Downstream
Noise Margin: 10.7 dB
Connection Rate: 7008 Kbps
Line Attenuation: 33.0 dB
Power: 19.8 dBm
Max Rate: 7552 Kbps
SF: 10145757
SF Errors: 18086
Reed Solomon: 689911506
RS Corrected: 6628454
RS Un-Corrected: 60968
HEC: 13864
Errored Seconds: 1529
Severe ES: 349
Interleave Depth: 32
Bitswaps: 0
Upstream
Noise Margin: 22.0 dB
Connection Rate: 448 Kbps
Line Attenuation: 19.5 dB
Power: 12.4 dBm
Max Rate: 1124 Kbps
SF: 10176267
SF Errors: 2
Reed Solomon: 86497037
RS Corrected: 28
RS Un-Corrected: 0
HEC: 2
Errored Seconds: 0
Severe ES: 0
Interleave Depth: 4
Bitswaps: 0
Total Uptimes (From SF counts):
WAN: 2 days, 00:03:58
LAN: 2 days, 02:24:37
CRC: 19263
LOS: 1
LOF: 9
ES : 1529
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Replying to my own post but i'd remembered i'd switched on Telnet on my router (DG834GT) and set the all the different errors to plot on Routerstats....each jump up in errors (CRC, SF error etc) occurs exactly when there is a noise blip (eg 1000 CRC errors over the duration of the spike (30secs to a minute)). To be expected i suppose so i'd guess these amount of errors arent normal!!
I do recall from a year or 2 back having a very small amount of CRC errors! :(
Another question....does the BT equipment at the exchange pick this sort of info up and would BT be able to look at it and realise something isnt as it should be?
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Hi
quote its lower than my normal 8128kbps
Interleave is back on so the synch can only be up to 7616Kbps
your stats for 48hrs
SF: 10145757
SF Errors: 18086
Reed Solomon: 689911506
RS Corrected: 6628454
RS Un-Corrected: 60968
the above relate to your WAN uptime (connection to the exchange )
HEC: 13864 ( not sure when these get reset )
those below are the total uptime errors since reboot , may be the same time as WAN time
Errored Seconds: 1529
Severe ES: 349
to me they seem high but that is by comparison to my line
my stats for a line with 29db attenuation
Wan up time of 1 days, 08:59:11
SF: 6975923
SF Errors: 1
Reed Solomon: 474362794
RS Corrected: 690
RS Un-Corrected: 1
HEC: 1
LAN uptime : 10 days, 08:37:39
Errored Seconds: 4
Severe ES: 0
Interleave Depth: 32
I still don't understand how your synch rate sometimes is so high and why with your problems your target SNR does not appear to be raised . Maybe that is part of the problem ?
Hope you get some help from BT (hope it gets very unstable during the 2hr test :fingers:)
Regards Jeff
edit : crossed your post
quote Routerstats....each jump up in errors (CRC, SF error etc) occurs exactly when there is a noise blip (eg 1000 CRC errors over the duration of the spike (30secs to a minute)).
the errors and drop in SNR margin and or disconnection will be related . the problem is which came first ?
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Jeff, i've always had interleave on and synced at 8128kbps....its possible and its not the router cus i've done it on 3 different routers. :D
Found an old post of mine from Nov 2007 from another forum and over 24hrs my 3COM router had reported:-
Defect Indication
Indicator Name Near End Indicator Far End Indicator
Fast Path FEC Correction 0 0
Interleaved Path FEC Correction 3060 6889268
Fast Path CRC Error 0 0
Interleaved Path CRC Error 0 32
Loss of Signal Defect 0 ---
Fast Path HEC Error 0 0
Interleaved Path HEC Error 0 0
Statistics
Received Cells 1217034
Transmitted Cells 230917
Obviously no problems there!
Before the BT engineer put my line on re-training i had had my SNR Margin increased to 9db by the DSLAM....now back on 6db still, i dont want it raised as that would just be trying to brush the underlying problem under the carpet.
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Ran BT speedtest as i felt the net wasnt running to fast and got:-
Download speedachieved during the test was - 40283204 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :7008 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 5500 Kbps
The green bar on the 0 - 7150 scale was really low though.
Speedtest.net and ThinkBroadband speed tester are all reporting 1.5-2mbit.....whenever i've tested in the past it been very near to my IP Profile (5000-7150).
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I have noted today that BT's speedtester is not working properly.
See:-
http://forum.kitz.co.uk/index.php/topic,6546.msg141008.html#new
I have tried two other lines today on the same exchange. On one the speedtester just hangs after entering the number and doesn't ask the question on the phone number pop-up.
The second was a brand new service I was commissioning and gave a stupid answer well above the sync speed again.
Kind reagrds,
Walter
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Line training now finished, just need the problem fixing now! ::)
MSR FTR MSR Reset Status Date
6240 4992 N 12-Jan-2010 02:05
288 288 N 02-Jan-2010 12:06
6816 4771 N 07-Mar-2007 02:02
2272 2272 N 26-Feb-2007 00:00
No idea why FTR is higher than my last setting when MSR is lower? ???
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Hi
What you describe throughout is impulse noise, there is nothing wrong with your phone line or setup especially if others experience the same thing.
It can very difficult to track down, logging dates and times will help towards possibly finding the cause, but you will need specialists at BT/Openreach to take an interest in fixing the problem, they will if they get enough complaints and someone makes the connection that the same impulse noise source is the cause.
Where this noise comes from? Could be anywhere? Anyone using electrical equipment could be the cause, and they are probably completely unaware it is having an effect.
Let us know how you get on.
Regards
Phil
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Others that i know of arent experiencing the same thing, my parents live 200-300 yards nearer to the exchange on the same road and i've monitored their connection and they dont get the same problem.
My next door neighbour doesnt have ADSL but i saw him today and he was going to order BT's own ADSL today.
I've been logging the SNR Margin/Sync on routerstats since 22nd Dec but my ISP (Zen) tell me BT wont take it into account and arent interested in it.
I've had everything in the house and garage turned off at some point trying to see if its me causing the issue and no changes.
BT Openworld came out for the 2nd time yesterday and the guy was supposed to monitor from the exchange but he said he'd come round and do a quick check (previous guy used the Hawk and laptop/modem from my house last time and then reset me onto the 10 day training). He found nothing (and broke my double extension splitter so i cant remove it from the faceplate now) and then said he'd go to the green cab and exchange to monitor and phone back later. He didnt.
Funnily enough an hour after he left my connection resynced and i didnt get a noise spike until 1.05am, i was almost thinking it was fixed as prior to that the latest it had gone into the evening without spiking was 9.45pm.
I saw 3 spikes overnight which was less than normal and tried a reboot of my router in the morning, it resynced at 8128kbps/7db noise margin which stuck for 1.5 hours before a large noise spike took it to -4db and caused a drop.
Synced now at 7456kbps/10db noise margin since then with no spikes, again prior to yesterday i saw a couple of spikes between 3pm and 5pm without fail but not today. Will just have to continue monitoring.
Zen have just replied to my fault log thats open and they say the BT guy claimed he tested with his own faceplate....he didnt, he used mine!!! ::)
I dont know what else the BT report says, whether anything has been changed.
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Hi Duckson,
It's a pity you can't persuade your neighbour to start with Zen as adjacent results would be invaluable.
If he doesn't want to afford Zen in the longer term he could transfer usually free of charge.
If you haven't already done so perhaps you could e-mail
Zen - Technical Support <support@zen.co.uk>
with pictures of some of your spikes in the hopes that Zen might convince BT O to call out a REIN specialist.
Kind regards,
Walter
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I think its a cost thing getting BT over Zen.
I have had a Fault ticket open with Zen since 22nd Dec, i've updated it with links to my plots but apparently BT wont have anything to do with them.
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Hi
quote I have had a Fault ticket open with Zen since 22nd Dec, i've updated it with links to my plots but apparently BT wont have anything to do with them.
I am surprised at that response . Using your info I would have expected the Zen help person to be able to see that there is a problem . THEY then push BT to solve it .
Regards Jeff
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Why not give your neighbour the £40.00 installation fee ? He / she is then only covering the monthly cost differential for say a couple of moinths, and can sign up to a nice long contract when he / she feels like it.
I realise this might be a wild goose chase, but if your neighbour is likely to suffer as you are, how does he / she expect to get a reasonable level of (often) Asian fault-finding service from BT ?
Kind regards,
Walter
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Hi
quote I have had a Fault ticket open with Zen since 22nd Dec, i've updated it with links to my plots but apparently BT wont have anything to do with them.
I am surprised at that response . Using your info I would have expected the Zen help person to be able to see that there is a problem . THEY then push BT to solve it .
Regards Jeff
Zen can see the problem but BT wont take them as evidence there is a problem....Zen have been pushing from what i've seen and they've said.
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Does this look reasonably normal? The bitswapping is alot higher than it normally is.
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2Fbitsswap.jpg&hash=a4398998c27d6064e27815a6b15b5a7a8e352bdc)
From Friday morning it has got better in that there are less spikes, still get drops though. You notice when it drops it sometimes reconnects at 8128kbps/~7db, i think when it doesnt do this the noise is still there and it cant reconnect at the max speed....i do notice when this happens the noise margin goes to 6-7db for a couple of plots (10 seconds) then shoots up to 9-11db due to the sync speed not being at 8128kbps hence my reasoning.
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan15-1144.jpg&hash=28267e7cf7ae8fac254a85b751962763a67c1521)
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan15-2153.jpg&hash=099e24be1184db6940d3a29558c4aa2e25e05bf8)
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan16-0754.jpg&hash=7d4b87f521f3d73a101b14f52b1a7fb97240b549)
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan16-1759.jpg&hash=cd60c7ed0bb4eb07edbecef66f8831720db830be)
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan17-0407.jpg&hash=7be4fe43912e9948a401455891be8d81adf0ae76)
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan17-1409.jpg&hash=f5b5f90c5a8ca86afc890c9744f531c16f6232a0)
The only thing i can think of is the external temperature is slightly warmer than it has been.
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Hi
quote
My next door neighbour doesnt have ADSL but i saw him today and he was going to order BT's own ADSL today.
All things being equal it will still be helpful to compare connections when your neighbour is connected . The fact that he is connected to BT should make no difference . The line connection speed,target SNR margin ,bit loading etc is done BEFORE the isp authentication. under normal circumstances you would expect your 2 connections to be in the same multi core cable or at least follow the same route to the exchange .
If possible get your neighbour to monitor using routerstats at the same time as you .
quote Note the massive noise spikes only occur when my nosie margin is around 9db for some odd reason, at 14/15db it doesnt spike that much "only" a 5/6db loss.
I think that that has to do with the actual "power " of the noise burst. remembering that each 3db is a doubling affect .
taking the base noise level as X at 0db(or any value) then 6db margin = 4x ,9db = 8x ,12db= 16x, 15 db = 32x .
so looking at spike when you have 15db margin that drops by 6db that in terms of actual power shows tha the noise mus have gone up by
a factor of 24 .
now if the same change ie and increase of noise of 24 times original happened when you only have 9db margin then the factor of 8 above the base line is swamped by this massive 24x noise spike . That's as I think it works .
the 3db between 3db and 6db is not the same in power terms as 3db between 12db and 15db .
Hope that makes sense :fingers:
Regards Jeff
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Thanks Jeff, i know what you mean i think! Its a Logarithmic scale after all.
Regarding my neighbour, i will have to see what he will do, he might allow me to monitor his connection wirelessly (get his router login of course) and that would be great to see if the noise spikes occured and if they happened at the same time. We do go back to the same pole on the road.
I will have to find out what the BT hub is like for using with routerstats or routerstats lite. My 3COM and Draytek wont run natively with it and i managed to set them up OK.
I might even suggest some other ISP, he can use my 3COM then which is spare if he doesnt get one for free!
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G'Day Duckson,
This has now been brought to my attention again. Could you please send me your fault rer and allow me the time to look at it. If you tell me the engineer has not done what he has suggested then this will need to be raised as a complaint and investigated. The fact the fault has been open since the 22/12/09 is a little worrying when you do not seem to have gotten any further.
Kindest Regards,
Leo
~Update: I have spoken to the person dealing with the fault and a formal compliant is being made against the engineer. I have PM'd Duckworth and will keep him informed as the goings on.
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Many Thanks Leo, Zen have been brilliant so far as I can see this fault is being a little bugger!! ???
However I am flabbergasted BT seemingly have no way of monitoring remotely or calling up a log of information from the exchanges equipment similar to what i can get from my own router.
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They can, but some of the agents dont have access to the systems for it and some have no idea what it means.
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They can, but some of the agents dont have access to the systems for it and some have no idea what it means.
In that case i'd politely suggest that BT find someone who can! :D
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BT coming out on Saturday to do a 6 hour test/checks...3rd time lucky! :-\
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hope it goes well :)
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BT coming out on Saturday to do a 6 hour test/checks...3rd time lucky! :-\
The engineer has been tasked for specifics, hence the 6hrs. If this doesnt work... then i'll have to start slapping harder.
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The engineer has been tasked for specifics, hence the 6hrs. If this doesnt work... then i'll have to start slapping harder.
Well :fingers: or it'll be time to :shoot: BT's rear.
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BTO been again this morning, he said it was only a 2 hour slot though and not a 6 hour.....seemed a bit more proactive this time and after the usual speed check and check with the Hawk (said line was bob on quality wise) he changed my ADSLNation faceplate filter for a BT faceplate filter (i'd tried 3 other filters as well with no change so doubted this would do anything) and fitted an RF3 filter where my exterior cable meets the interior (just a junction box previously). Said he was going to remake the connection at the Green Cab and check the soldered connection at the exchange and then i was to see how it goes....if it didnt fix it i'd have to log it with my ISP again.
Anyway i synced up at 8128kbps / 7db for a couple of hours before the inevitable spiking occured and took out the sync, must of reconnected when the noise was still occuring.
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.duckworth.myzen.co.uk%2Frouter%2FNetgear%2FRx_Noise_margin_%28dB%29-2010Jan23-1323.jpg&hash=0bfc8a9a5bc5583be3c6252d367cda494e9c0b9a)
I also mentioned REIN and he said he was a REIN engineer and he didnt think it was REIN when he'd viewed some of my logs.
Back to the ISP then but what now? Guess they are going to have to start swapping D+E side cables or lift+shift at the exchange..... :rain:
Here's to 4th time lucky eh? ::)
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Just to keep this up to date, a Lift and Shift is being done tomorrow (Saturday) morning, will keep this updated on how things turn out.
The noise spikes have varied from having rampant noise spikes and 12 losses of sync within 48hrs to having just one noise spike in 24hours!
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Well lift + shift has been done (eventually, almost had to explain that is what the booking was for...) and its to early to tell if the resyncs/noise spikes are gone. One thing that is good though is my noise margin has got better. When synced up at 8128kbps its gone from ~7.5db to ~9db after the lift and shift (attenuation is the same).
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:fingers:
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Well it did drop shortly after in 2 occasions but since then i've now noticed i'm on Fastpath instead of interleaved, also my nosie margin is back at around 7-7.5db under daylight hours. Would Fastpath reduce my noise margin over interleaved? The noise margin when it had reconnected on Fastpath is somewhat more spikey/varying quite alot compared to before the resync.
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Hi
quote Would Fastpath reduce my noise margin over interleaved?
No Your noise margin is totally dependant on the actual signal to noise ratio. The Margin can be thought of as the amount of elbow room between the the data and the Actual SNR .
see SNR explanation (http://www.kitz.co.uk/adsl/linestats.htm#SNR)
Interleave is part of the error correction system.
Regards Jeff
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Thought i'd update this.
After the Lift+shift was done on the 6th Feb it didnt improve things and i was still seeing resyncs and noise spikes (sudden drops in noise margin for 1-2 minutes), it is now being monitored by BT but they wont pass it to the CFI team (as yet anyway).
I think this is because funnily enough over the last week its been the best its been since the fault reared its ugly head in early December. I seem to have been put on a 12db noise margin profile and I've had quite a number of days/nights where there have been no noise spikes at all plus my SNR Margin has varied day to night by 1db max, previous to this it was varying up to 2db day-night.....last night was the best yet, it moved maybe 0.5db compared to the daytime figure!
Now i've been connected at 12db and even 15db when i've had a 6db profile, i assume this would just operate the same even with a 12db profile? If i am connected at a 12db or 15db noise margin there would be no difference in performance/how the line is seen by the exchange etc with having a 6db or 12db noise margin profile (or target maybe a better word)?
Anyway link to my latest routerstats graphs:- http://www.duckworth.myzen.co.uk/router/Netgear/Feb/
So i dont know if something has been tweaked somewhere other than my target SNR Margin or whats going on! :-\
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The target noise margin is only used at the time of negotiating the connection. It isn't taken into account continuously through the life of the connection. But all sorts of things can vary according to signal conditions, so a 12 dB noise margin at two different times could be made up in quite different ways, depending on the bitloading.
But none of this explains the current absence of noise pulses. That's not the result of differences in the mode of connection, it's because something has changed so that the interference isn't there at the moment. If the noise pulses are caused by an intermittent line fault, then that intermittent fault is currently in remission, so to speak; and if it's electrical interference, then the source of that interference isn't active at the moment. My guess (no more than that) would be an intermittent line fault, mainly because I see very similar effects on my own connection.
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Hi
quote: Now i've been connected at 12db and even 15db when i've had a 6db profile, i assume this would just operate the same even with a 12db profile? If i am connected at a 12db or 15db noise margin there would be no difference in performance/how the line is seen by the exchange etc with having a 6db or 12db noise margin profile (or target maybe a better word)?
Not too sure what you mean?
Remember increased Target SNR reduces synch rate .
Something else to be aware of is that the spikes of -3db seen at 15db could well equate to a loss of synch if the same noise was produced when the margin was say 10db.
It would seem that your target may have been dropped from 15db to 12db on the 23feb this increased your synch rate to 7040 from 5888Kbps .
Seems like there are less spikes . :) last one seems to be on 25th where a resynch was forced dropping the Synch rate a little to 6848 from 7040Kbps.
Regards Jeff
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Hi Jeff,
When it was on 15db i had a 9db profile, it dropped and reconnected but must of been experiencing the noise at the time and hence synced at the lower kbps meaning a higher noise margin when the noise went away.
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Hi
quote When it was on 15db i had a 9db profile
Not too sure what you are trying to say ?
When you connect to the exchange that is when your target SNR margin is applied as part of the negotiation between your router and the DLM. So if you Connect at X speed with say 14.8 db SNRM then its likely that your target is 15db.
If at the time you connect you may get a low synch speed because the noise on the line is high. As the line quietens down then the snrm will go up .resynching at that point will result in a conection with a similar SNRmargin of around 15db but with an improved synch speed .
If at the time you connect the noise on the line is low then you will still connect with the SNR margin reflecting your target SNR say of 15db
with a connection speed of Y Kbps. If the noise increases you will see the snr margin go down . Resynching at that point will synch using the same target SNRM (say 15db) but because the increased noise on the line the synch speed will drop.
Regards Jeff
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Yes Jeff, what you explain is exactly what i said (or meant if you didnt get me!). I synced at 9db with a lower speed cus the noise was high at the time, when the noise went away (i'm taking 30-60 seconds later) then the margin went up to 15db.
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Hi
The last resynch 25thfeb shows about 12db snr margin !.
I might have missed it but I have not seen any sign of a 9db SNR margin at synch time rising to 12 or more . :(
BTW webpages where you have your graphs are , is shown as unsatisfactory by WOT (Web Of Trust)
Regards Jeff
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I meant before that time, 20th Feb (1st one in the list) on here :- http://www.duckworth.myzen.co.uk/router/Netgear/Feb/
Yes the other time it resynced at 12db, i'm wondering if the resync occured due to BT changing me from a 9db to 12db profile.
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Hi
That first one showed the current(then) SNR margin of 12db,was that the original target or did the snr margin drop to that over a period of time ?? .A massive spike of about -12db caused a resynch(note*) to a lower synch rate with an SNR margin of ~15db ,this appears to indicate the target SNR margin to be 15db. Then several spikes of -3db or more (note*) at this level of SNR margin the line held .
note *: this illustrates exactly the effects of higher SNRM , a -3db noise spike at 15db is ~= to a -12db spike on a 12 db SNR margin.where you would expect to lose synch.(as it did)
Regards Jeff
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I am having similar problems. In fact I had this sort of problem back in late January 2010 through a good deal of February 2010. I raised a ticket with my ISP which eventually resulted in a BT engineer attending. The engineer did not do anything specific to fix the problem. I think the problem had 'fixed itself' before the engineer arrived. Prior to the problem I had been on 8128kbps, during the problem the downstream speed reduced to less than 5000kbps. After it fixed itself it went back to 8128kbps.
I have added this reply, because after several months of steady performance at 8128kbps 9dB SNRMargin, the connection started the same symptoms again last weekend (15 August 2010). I have Routerstat plots that look very similar to those of Duckson. This looks like the 'signature' of the problem. If it was steady interference surely the line would just sit at some high downstream SNR margin and lowish speed. What seems to be happening is more abrupt, almost like the connection is being switched off and on. Now obviously some electrical interference could casue that, something being switched on and off. I have checked within our property and there is no obvious on/off event anywhere in the property that coincides with the spikes. I have used a medium wave portable radio to check for noise, there is nothin continuous, but you would be lucky to catch a burst of noise if that is what is causing the drop outs.
By the way, at the downstream drop outs, the upstream goes down too, I guess that is going to happen as the re-synch will involve both. I have noticed the latest re-synch changed the upstream SNRMargin from around 12dB to 24dB with speed steady at 450kbps, at the same re-synch downstream went to 6336kbps and 15dB.
I have not provided the Routerstat graphs as they show such similar behaviour. In the 30 minutes I have been reading this thread and composing the reply, the downstream SNRMargin has gone to zero 4 times, with the speed also dropping to zero and then coming back up again (Netgear DG834GT by the way).
I know this thread is fairly old. Is this type of fault somethnig others have experienced?
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This is a reply to my own post, dated 17 August 2010. It has taken this long for me to be reasonably sure I have tracked down the problem with my ADSL conection.
In my last post I stated a BT engineer attended in February 2010 but did not do anything specific to fix the problem. Actually there were 2 BT engineer visits. The first did some checks but never made a report back to the ISP, so the ISP requested a second visit. The Second BT Openreach engineer did some checks and changed the connection block in the junction box attached to the outside wall of our house. By the way the phone line goes immediately underground from this outside junction box; as far as I know it is underground all the way to the exchange (other than going into the odd green cabinet en-route).
As noted in my last post none of the Openreach visits cured the intermittent problem. The problem came back in August / September 2010.
I have been suffering from this intermittent problem for literally years and have looked into many of the popular claimed reasons for bad connections (radio interference, domestic appliances, neon lights in power connector blocks). The frustration is, when the line is ok it is as good as it gets - 8128kbps downstream.
Something that has changed since early 2010 is I retired, and have had more time to fault trace and test what was going on.
In early 2011 I decided to go back to basics and start with the router (Netgear DG834GT) connected direct to the Master Socket 'test socket', without any phone equipment connected. In setting up the router in this way, I realised something I had not noticed before. In February 2010 the Openreach engineer had changed the Mater Socket inside the house, as well as the connection block in the junction box on the outside wall - BUT he had not changed the faceplate. The old Master Socket had the BT and "piper" logo in the top left corner (from 1993, when the house was built), the new Master Socket has the Openreach logo in the top left corner. But I realised the faceplate was the original from the original (1993) Master Socket.
In the past I had checked extensively the phone wiring in the house. And the wiring to the exchange is all underground and relatively new (and all copper according to the 2nd Openreach engineer). I began to wonder whether the problem was something to do with the faceplate itself. However I have thought I had found the cause of the problem before, only for it to return at a later date. So I needed to do some testing to check out the faceplate theory.
There are two 'spur' phone lines in the house, leading from the Master Socket. By the way, over the (literally) years I have had this intermittent problem, these two spur lines have been connected:
1. both plugged into the front socket of the faceplate (using a doubler plug);
2. One connected to the IDC connectors on the back of the faceplate, the second plugged into the front socket of the faceplate.
When the Openreach engineer attended, the two spurs were connected as in 2 above; maybe that is why he did not touch it - but that is beside the point.
I did about 2 months of testing with the faceplate out of the connection path. I will not go into details about what that involved but it was all legal, I did not touch the Master Socket itself. I concluded it is somewhere in the circuit board in the faceplate leading to the 'plug' on the back of the faceplate, or a fault in the faceplate 'plug' connectors.
Having convinced myself it was something to do with an intermittent connectivity or connection issue in the faceplate, in March 2011 I went to Maplin and bought a standard NTE5A Master Socket. I took the faceplate from the Maplin Master Socket and put it on the Openreach Master Socket. This new faceplate does not have any microfilter, it is a standard faceplate. The two spur lines are connected to the new faceplate using method 2 above (one on the IDC connectors, the other plugged into the front).
From the time I started my testing in February 2011 to now (end January 2012), the intermittent connection problem has not occurred, most of that time has been with the new faceplate. Of course there has been the odd issue with power cuts causing re-syncs. As of today, since last re-sync, the ADSL connection has been running for 40 days (downstream: speed 8128kbps, attenuation 22dB, noise margin 8.3dB - RCO 86%, 9440kbps) and the total CRC errors are 77 in 77 error seconds, with no Severe Error Seconds. The CRC errors seem to occur mostly when there is an incoming call and so a ring in event. Sometimes an incoming call does not cause and CRC erros, and somtimes they seem to occur with no obvious reason. I noticed this happens even when the router alone is connected direct to the test socket. But as this level of CRC errors does not cause any problems, I have not tried to sort it.
Since changing the faceplate, the longest continuous run has been 100 days (8128kbps downstream speed) - in Autumn 2011. That ended when I realised that although the downstream speed was 8128kbps, and my ISP showed the current speed as 7150kbps (correct IP profile number for the speed of 8128), the bRAS had somehow become stuck at 2000kbps. It took over 2 weeks of ticket tennis with my ISP to get BT to reset the bRAS.
For me, the circumstantial evidence is my intermittent ADSL connection issue was a simple continuity / connectivity issue in some part of the original Master Socket faceplate. The faceplate was certainly not changed when the rest of the Master Socket was changed in early 2010. Since changing the faceplate for a new one the intermittent problem has not recurred.
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Thanks.
I havent really looked into mine properly since those previous postings, although i got Zen to get BT to reset my target noise margin from 15dB to 6dB back in October 2011. It went back up to 15dB after 3-4 weeks though but i didnt really monitor it.
A fwe weeks ago we finally got an LLU provider in my exchange and so i'm now on TalkTalk LLU through a reseller called XILO....no more profiling and automatic upping of the target noise margin! hurrah! I've been messing about with 3 routers and had a power cut to boot so i havent spend more than a few days connected but will leave it since my last reboot which was sometime at the weekend to see how it goes.
One thing though I have done is change the cable between the RF3 filter (where the external drop wire terminates) and the master socket as the existing item was split open in a couple of places as it was run under carpets infront of doorways so was always stood on....now while not allowed i have left the existing cable in there so could reconnect it up at any time.
Can you clarify to me which part you have replaced?
There is the bottom half faceplate which you can remove to get to the test socket and there is the main master socket plate which the wiring from BT terminates at...which did you replace?
(Note i have removed the bottom half and use a filtered face plate, tried 2 different types, one BT gave me and an ADSLNation one).
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I replaced the bottom half faceplate on the front of the Master Socket.
I have not looked at changing to an LLU provider, though at least one is available on our exchange, on the basis that my problem has always been somewhere in the wires between our router and the exchange. I have always doubted that changing the hardware in the exchange would have any benefit. I just wish cable was an option.
Now I think I have fixed my problem, I could be in a position to change. However our exchange is due to go onto ADSL2+ soon. Be interesting to see how that works. My overall conclusion from my years of problems is whether it is Century 20 or 21 hardware at each end, the ends are connected by Century 19 type wiring and that is the weak link.
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My overall conclusion from my years of problems is whether it is Century 20 or 21 hardware at each end, the ends are connected by Century 19 type wiring and that is the weak link.
A very succinct statement! :)