Kitz Forum
Broadband Related => Broadband Technology => Topic started by: UncleUB on February 04, 2009, 09:47:52 AM
-
Hi all,
Ever since I have been with BT BB my line has only been able to support up to 1mb(according to various linecheckers including the one on this site)
I checked it the other day and now it says my line can support up to 1.5mb
For the last few weeks my IP profile has been 2000kbps.I am on a long line 63.5 down and 31.5 up attenuation.Can something have been put in place to make my line support a bit faster connection speed.
(Copied on 2009-02-04 09:41:22)
Download: 1947 Kbit/s
Upload : 377 kbit/s
Connects : 1727 conn/min
Ping: 47 ms
-
The line checkers only read data from the BT database, which tends to be conservative; they don't actually check the line. I suspect that what's happened in your case is that your physical line has improved in some way, giving you a higher connection speed, and the database has caught up with this improvement and is now indicating a higher capability than it did before. The improvement could be something as simple as an Openreach engineer noticing a corroded joint and repairing it, or something like that.
-
Oh I see,thanks Eric. :)
-
The line checkers only read data from the BT database, which tends to be conservative; they don't actually check the line. I suspect that what's happened in your case is that your physical line has improved in some way, giving you a higher connection speed, and the database has caught up with this improvement and is now indicating a higher capability than it did before. The improvement could be something as simple as an Openreach engineer noticing a corroded joint and repairing it, or something like that.
Eric,
I don't want to contradict you (as I'm sure I'd be wrong), but I can't resist pointing out that the 'BTw estimators' for my line have, with some lag, tracked the improvements I've made (all thanks to this forum), which have resulted in getting my speed up from the middel 1xxx's to the high 3xxx's. Each step in the improvement has corresponded to some action on my part (cutting the bell wire, optimising filters, different router etc.).
Also, one day a week or three ago I got resynched late at night and got a lower connection speed. I left it that way for a while out of curiousity to see how the error rates were affected , which is irrelevant to this topic, but I'm fairly sure I noticed the BTw estimator also reduced it's guess at that time.
At risk of going slightly off-topic, I think I once read on a forum (don't know if it was kitz) a suggestion that a target margin reduction may co-incide with a revised value from the BTw estimator. In my case, that's not been so. Target SNR stuck at 15 since last summer, manually tweaked down a little, but in that time the BTw estimator has increased from 1mbps to 3mbps.
-
I don't want to contradict you
Actually, I don't think I am contradicing you, which is good. I'm not sure why I thought I was. :-[
-
Just to add to my earlier post.I have always had my router plugged into the main socket,don't have any extensions in the house.I have never tweaked anything,just left it to run its course so to speak.
Here's my latest stats.
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 15:19:49:29
Line Coding Trellis On Line Up Count 18
Statistics Downstream Upstream
Line Rate 2528 Kbps 448 Kbps
Noise Margin 6.1 dB 12.0 dB
Line Attenuation 63.5 dB 31.5 dB
Output Power 17.3 dBm 12.2 dBm
K (number of bytes in DMT frame) 80 15
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 2 8
D (interleaver depth) 16 4
Super Frames 80432693 80432691
Super Frame Errors 5020 654
RS Words 2734711574 146806961
RS Correctable Errors 16120031 8684
RS Uncorrectable Errors 28231 0
HEC Errors 4548 0
OCD Errors 61 0
LCD Errors 0 0
ES Errors 0 0
-
Just to add to my earlier post.I have always had my router plugged into the main socket,don't have any extensions in the house.I have never tweaked anything,just left it to run its course so to speak.
Here's my latest stats.
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 15:19:49:29
Line Coding Trellis On Line Up Count 18
Statistics Downstream Upstream
Line Rate 2528 Kbps 448 Kbps
Noise Margin 6.1 dB 12.0 dB
Line Attenuation 63.5 dB 31.5 dB
Output Power 17.3 dBm 12.2 dBm
K (number of bytes in DMT frame) 80 15
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 2 8
D (interleaver depth) 16 4
Super Frames 80432693 80432691
Super Frame Errors 5020 654
RS Words 2734711574 146806961
RS Correctable Errors 16120031 8684
RS Uncorrectable Errors 28231 0
HEC Errors 4548 0
OCD Errors 61 0
LCD Errors 0 0
ES Errors 0 0
Uncle,
I think the only difference between us is is that in your case the line has improved for reasons unkown, so as Eric says, it may have been some Engineering work by Openreach that led to an improvement. In my case, it was my own fiddling that brought about the improvements.
In both cases the improvements led to the same outcome... a higher estimate, reflecting that fact that improvements have occured, regardless of who made the improvements.
-
iirc UB, your line has always been pretty good considering its length. - correct me if Im wrong cause I see lots of stats - but I seem to recall that youve always been able to sync at over or above 1.5Mb despite the records saying 1Mb
I'm guessing here that this could be twofold
1) I think perhaps as eric says that perhaps a joint has been replaced which may account for that little bit more sync speed.
2) The Btw data base has finally caught up with the fact that you reliably sync at >1.5Mb and has updated. - It only took BT 2 years to catch up on mine.
As SLM suggested it may be that as a result of 1), then 2) has occurred.
-
@ Kitz,yes thats right I have always had an IP profile of 1.5kbps to 1.75kbps,its just the last few weeks I have had an IP profile of 2000kbps.I have never reached speed before.
Just to add when I first started with BT BB in May 2007 my downstream snr was around 14 to 15 and over time has gradually reduced until its reached the around 6.0 mark.
Is it correct in saying that reduction is due to the stability in my line.
-
>> Is it correct in saying that reduction is due to the stability in my line.
Yes :)
... and as your Target SNR reduces, then that enables you to sync at a higher speed.
-
Well just noticed I had a re-sync about 5 hours ago.I can't believe it has re-synced at 3072downstream :o
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 00:05:11:50
Line Coding Trellis On Line Up Count 19
Statistics Downstream Upstream
Line Rate 3072 Kbps 448 Kbps
Noise Margin 5.8 dB 12.0 dB
Line Attenuation 63.5 dB 31.5 dB
Output Power 17.9 dBm 12.0 dBm
K (number of bytes in DMT frame) 97 15
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 2 8
D (interleaver depth) 16 4
Super Frames 1100585 1100583
Super Frame Errors 163 14
RS Words 37419902 9354955
RS Correctable Errors 16848 178
RS Uncorrectable Errors 2996 0
HEC Errors 122 0
OCD Errors 12 0
LCD Errors 0 0
ES Errors 0 0
If that maintains itself It will give me an IP profile of 2500kbps :thumbs: :dance:
-
You'd better not breathe on it, just in case :)
-
I am presently holding my breath too - about a month ago I dropped from 3.8meg to 1.9meg for no immediately obvious reason. Yesterday we had a 3 hour power cut in the village, but only on one phase (our phase!!!). Over the past month, our house lights have been flickering quite a lot in wet weather. The power company told me that a joint on an overhead line in the fields had been arcing (now they tell me), probably for a whole month and then eventually failed. At times over the month, REIN has been evident in a very spikey chart for my broadband connection.
Once the power came back on yesterday, and naturally the REIN had stopped, I re-synced at 4.3meg. Now I am just hoping it won't take a dive again.
Fingers crossed!
[attachment deleted by admin]
-
:fingers:
-
Who sneezed. ?
Re-synched 43 minutes ago,but not much less than previous one.
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 00:00:45:03
Line Coding Trellis On Line Up Count 20
Statistics Downstream Upstream
Line Rate 2976 Kbps 448 Kbps
Noise Margin 5.9 dB 12.0 dB
Line Attenuation 63.5 dB 31.5 dB
Output Power 17.6 dBm 12.4 dBm
K (number of bytes in DMT frame) 94 15
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 2 8
D (interleaver depth) 16 4
Super Frames 159004 159002
Super Frame Errors 12 0
RS Words 5406148 1351517
RS Correctable Errors 1579 8
RS Uncorrectable Errors 53 0
HEC Errors 12 0
OCD Errors 0 0
LCD Errors 0 0
ES Errors 0 0
-
Judging from your line stats before and after - it looks like there was a very quick noise burst.
Did a neighbour come home turn on something on... flick of a switch electric type of thing. Main thing is that it has recovered, so what ever it was was very rapid.
-
Looks like someone sneezed here too! Down from 4.3meg :'(
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.speedtest.net%2Fresult%2F405750708.png&hash=e895db693f282d9d5351cb06f2e8fd9e02e5f93d) (http://www.speedtest.net)
-
:'(
-
:'(
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 00:01:18:34
Line Coding Trellis On Line Up Count 21
Statistics Downstream Upstream
Line Rate 2624 Kbps 448 Kbps
Noise Margin 6.0 dB 12.0 dB
Line Attenuation 63.5 dB 31.5 dB
Output Power 17.7 dBm 12.2 dBm
K (number of bytes in DMT frame) 83 15
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 2 8
D (interleaver depth) 16 4
Super Frames 277240 277238
Super Frame Errors 1 0
RS Words 9426172 2356523
RS Correctable Errors 4576 0
RS Uncorrectable Errors 14 0
HEC Errors 1 0
OCD Errors 0 0
LCD Errors 0 0
ES Errors 0 0
-
Wayhay - back up to the dizzy 4+meg level again - maybe it was congestion late yesterday? :thumbs:
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.speedtest.net%2Fresult%2F406110506.png&hash=336009a52e9554c07a8e5a412030bcbc2ad6109e) (http://www.speedtest.net)
Colin
-
Wayhay - back up to the dizzy 4+meg level again - maybe it was congestion late yesterday? :thumbs:
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.speedtest.net%2Fresult%2F406110506.png&hash=336009a52e9554c07a8e5a412030bcbc2ad6109e) (http://www.speedtest.net)
Colin
Your upload looks low Colin ?
-
It varies a lot, between 150 and 360 - not sure why, but very happy with the download as I do a lot of online reading of research info and reports as part of one of my "retirement jos". Waiting for pdfs to download meant I was drinking lots of coffee - now the speed is back up, coffee consumption goes down.
I make a lot of use of the BT OpenZone/Fon WiFi when out and about and so I am stuck with the BT Home Hub as I have "let" OpenZone have enable public access in exchange for free FON minutes. Otherwise, I would join others here and tweak my modem/router.
Colin
-
Here's a better one
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.speedtest.net%2Fresult%2F406141648.png&hash=274f31f1c1451005640b130d213b306c50b47f0a) (http://www.speedtest.net)
I have found (as have we all I am sure) that it pays to perform a series of tests over the course of the day rather than concentrate on one isolated set of results.
Just keeping my fingers crossed that it stays high!
-
The second result looks more normal.
The earlier one could have either been something else using the upstream - in which case check your sync speed to make sure all is well. Also worth checking is the upstream CRC type errors which can cause slow throughput.
-
:fingers:
Can anyone shed any light on this
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.speedtest.net%2Fresult%2F406998713.png&hash=352f3d571e266c16ffa4d4617e0b6151a39d78a3) (http://www.speedtest.net)
It kept happening this afternoon.
Here are the stats, attached
[attachment deleted by admin]
-
Hi
Greased lightning :lol:
-
:)
It's just a defective result from the speed test site. It happens from time to time.
-
:lol:
-
Do the attached stats, taken from the BT Home Hub say anything though?
-
Sorry colin I was too busy laughing at impossible speedtest :-[
The stats look fine.. Youre syncing within acceptable parameters for the length of your line,
The downstream errors are racking up, but if those were spread out over 3 days, then your line should be able to cope quite well.
The 230 upstream Errored seconds are weird, because theres no actual CRC/HEC upstream errors recorded, and since the upstream SNR is good so it could be an old record retained by the dslam.
Theres an awful lot of FECs, but again it looks like the router is coping. Interleaving is working well and benefiting your line.
-
;) Speedtest was a laugh wasn't it. Thanks though for the reassurance, since the last 3 months have seen some wierd results, including that dip and climb back out. I am a fair distance from the exchange and didn't expect any better than around 2meg, but the latest recovery to 4.4meg is certainly welcome.
Colin
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.speedtest.net%2Fresult%2F407309451.png&hash=555204c23df60ff14b572c49da9c0799c74b5d97) (http://www.speedtest.net)
-
:wall: :hmm: :mad: :'(
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.speedtest.net%2Fresult%2F408020277.png&hash=de05aef59c20d2cca903947ddf356d0c25c0aecc) (http://www.speedtest.net)
Been like this now for a fair few hours and seems to have reset itself 8 hours ago - we didn't have any power cuts.
Colin
[attachment deleted by admin]
-
Colin,have you run the BT speedtester to see what results you get.
www.speedtester.bt.com
-
Here they are, and also a sample of the past week of monitoring by Samknows (I have one of their monitors on the line):
[attachment deleted by admin]
-
It looks like your line may have become noisy :(
Its lost the connection at some point recently and judging from your stats now, its had to sync at a lower speed to be able to cope.
Unfortunately the lower sync speed will now also land you with a lower IPprofile which is going to affect your throughput.
Time to get routerstats (http://www.vwlowen.co.uk/internet/files.htm) running on the line to monitor the SNR to see if it can pin-point any patterns in the noise.
-
I now have routerstats lite running is that OK?
Noise margin is currently (only been running 15 minutes so far) sat at 12 dB.
-
Yes should be fine - its your SNRM that needs monitoring.
-
Since I have a BT Home Hub v.1 am I right in assuming that only the Lite version will run OK? CORRECTION - The noise MARGIN is 12dB
See attached
[attachment deleted by admin]
-
I'm not sure what your PDF was meant to be, but all it shows is the up and down noise margins. If you want to attach a graphic, a .gif or .png is usually more effective. (Hope you don't mind my saying this :) )
-
Whoops! - you're right, I put the wrong attachment on - senior moment :-[
Since then, this occurred see png attachment
[EDIT] and the BT Home Hub shows one loss of signal (local) in its detailed link information page.
[attachment deleted by admin]
-
Did the router record that loss of signal at the time where the Routerstats graph shows the brief dip, or was it unconnected? The reason I ask is that Routerstats and RS-Lite do sometimes display a glitch like that, but it's not a real connection drop but merely one sample which RS failed to get from the router. If the connection speed was unchanged, I think that it's likely to be the latter.
-
The router shows one loss of signal (and only one) that occurred around the same time - it is on another floor from where I work and, naturally I am monitoring it through the network. Interesting though, the SNRM has now gone down to 11.5
[EDIT] - being a BT Home Hub, I can't get at the stats to look at timing of the loss.
-
This is more recent - attached
[attachment deleted by admin]
-
Routerstats and RS-Lite do sometimes display a glitch like that, but it's not a real connection drop but merely one sample which RS failed to get from the router. If the connection speed was unchanged, I think that it's likely to be the latter.
It appears unchanged at 2528 so certainly just a missing data point.
It behaves like that for me; I sometimes use DMT to check for certain that it's not done a resync at the same speed, but it never does.
-
Yes, the speed of the recovery (only one sample missed) also supports that view.
-
Phew :hmm: - thanks guys - I had images of someone at the exchange or street cabinet waggling the connection! :-\
-
This is tonight's state of play
[attachment deleted by admin]
-
Nothing wrong with that at all!! I wish my line was that stable!
-
Retires reassured and happy! 8)
Thank you all guys - just was a little bothered when it went up to 4.3meg for a month and then sunk back to 1.9meg again - hoping it didn't sink any lower.
Once again, THANKS! :drink:
-
Just to update my original post.It has been 22 days since my router last re-synced,prior to that I had a period of about 2 weeks when it was re syncing at least once a day.
My downstream snr has been steady between 4.5 and 4.6 in the last 3 weeks.
I can't understand why suddenly it is rock steady and prior to that it was always re-syncing.I have never done anything any different.
Router Stats........
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 22:02:09:06
Line Coding Trellis On Line Up Count 37
Statistics Downstream Upstream
Line Rate 2400 Kbps 448 Kbps
Noise Margin 4.6 dB 12.0 dB
Line Attenuation 63.5 dB 31.5 dB
Output Power 17.7 dBm 12.3 dBm
K (number of bytes in DMT frame) 76 15
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 2 8
D (interleaver depth) 16 4
Super Frames 112266320 112266318
Super Frame Errors 11965 914
RS Words 3817054892 417392791
RS Correctable Errors 117892809 9426
RS Uncorrectable Errors 38396 0
HEC Errors 10522 0
OCD Errors 67 0
LCD Errors 0 0
ES Errors 0 0
-
I guess there was some extra interference around up to three weeks ago. It could be any number of things over which you have little or no control, and a high attenuation line like yours is always going to be vulnerable to such things.
-
Thanks Eric,
As regards interference I tried to narrow things down,but nothing (in my house anyway) seemed to coincide with the re-sync's.Tbh with my attenuation being what it is I am very pleased to be getting around 2mb.
-
A similar thing has happened again,
After being rock steady for 7 weeks my connections has re-synced 4 times in the last 24 hours.
It was 2240/448
then 1856/448
then 1888/448
and now 2112/448.
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 00:00:11:46
Line Coding Trellis On Line Up Count 9
Statistics Downstream Upstream
Line Rate 2112 Kbps 448 Kbps
Noise Margin 5.6 dB 14.0 dB
Line Attenuation 63.5 dB 31.5 dB
Output Power 17.8 dBm 12.3 dBm
K (number of bytes in DMT frame) 67 15
R (number of check bytes in RS code word) 16 16
S (RS code word size in DMT frame) 2 8
D (interleaver depth) 16 4
Super Frames 41476 41474
Super Frame Errors 0 0
RS Words 1410196 352529
RS Correctable Errors 5280 0
RS Uncorrectable Errors 0 0
HEC Errors 0 0
OCD Errors 0 0
LCD Errors 0 0
ES Errors 0 0
-
Hopefully it's just a temporary situation, which is likely to recur periodically.
-
Hopefully it's just a temporary situation, which is likely to recur periodically.
I hope so Eric. :fingers:
I can't pin it down to any interference( not from our house at least)
One good thing is when it re sync's there isn't much variation in the downstream speed.
-
The one thing I have noticed is the times of the re-syncs, 07.05am and 17.08pm.There is nothing in my home that is switched on/or off at those times.
I wouldn't imagine that any of my neighbours switch things on at those times,it just seems strange that I go weeks without re-syncing and then when it does,it does so at those times.???
Its not really a problem ,my downstream has only gone from max 2240 to min 1856 in that period of 7 re-syncs in 3 days.
The latest re-sync at 07.05 today is 2080/448
I have also noticed the interleaver depth downstream keeps changing from 8 to 16.The upstream is 4 .
-
It sounds as though your next-door neighbour has got a dodgy central heating thermostat, or something like that.
-
It sounds as though your next-door neighbour has got a dodgy central heating thermostat, or something like that.
M'mm,Its just that it goes all those weeks without re-syncing then............If something is dodgy next door,why isn't it causing re-sync's all the time..........
-
why isn't it causing re-sync's all the time..........
Thermostats only work intermittently, when putting heating on and putting it off.
As they are trying to maintain a constant temperature, they can go on and off a few times an hour, maybe the cause of your issues... :-\
-
As regards it could be a neighbours house,what is the maximum distance it could affect my router.I live in a semi and also have the other neighbour just across the driveway.
We also have an electricity sub station across the road.
My router re-synced at the mentioned time of 17.08 last night,I was waiting this morning for the 07.05am re-sync.......but it didn't. :)
-
Hi UncleUB,
I think you are asking an impossible question in a highly complex subject. There are many different forms of direct and indirect REIN / RFI and hopefully ezzer can provide some examples of his experiencs. From the radio transmission viewpoint there will be some form of square law of distance and radiated power. Antenna physics regarding aerial lengths and angular alignment will probably be involved.
Then there is the actual method of absorption by your equipment and line. The one I solved by accident recently happened to be caused by PIR Lights on the next but one's garage which affected the neighbour's lines and infected "our" circuit via cross talk in the riser cable from a road joint pit. Last year I came across another crosstalk problem which was caused by an old analogue wireless phone only when it was being used in a house three roads away from the affected house, but all fed from the same cabinet and D side cable. The permutations are endless.
How to solve the problem might be a more profitable approach. (Again HELP ezzer.) You could try a quiet line test at the expected time to see if anything can be gleaned that way. You could try the AM wireless method on several occasions with the radio being rotated to try to find the direction. You could run Routerstats as fast as you dare over the time periods. An audio recorder or an oscilloscope attached to the line or to a wire coiled around your line might be another approach. Re-siteing the modem or using different cables and mains filtering could be tried. Experimenting with an RF3 filter might hide the problem, but at the risk of reducing overall performance. etc. etc.
I hope these ramblings might trigger thoughts from others.
Kind regards,
Walter
-
Thanks for your input Walter,
There certainly much to ponder there.
Its thrown the spanner in the works as my router didn't re-sync at the expected time this morning.
One observation I have made is my line can be steady for weeks,but when it re-syncs it does so a few times in 3 or 4 days then settles down again.
-
Could be a pump coming into life rather than the thermostat itself.
Anything with a mechanical elemant can be quite variable.