Kitz Forum
Broadband Related => ADSL Issues => Topic started by: mist on August 15, 2009, 04:51:52 PM
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After my ISP agreed to reset my SNR to default of 6db which held steady on routerstatslite suddenly today it has returned to a 9db SNR. :'(
We have noticed on routerstats that it shows the regular sudden dips in synch and this morning by sheer fluke we noticed that when it happens the little screen bottom right of monitor (Vista) shows a 'yellow warning triangle followed by a redX on it a few seconds later it will get the blue connected symbol again. Now we know what to look for :o Also today I am getting a noisy line showing again.
I have checked that all settings are entered correctly in Netgear DG834N with firmware V1.02.15
All ideas welcome but I am not very techy..
System Up Time 28:25:33
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 1043 1294 0 204 711 00:23:09
LAN 10M/100M 195008 139733 0 1745 158 28:25:24
WLAN 11M/54M/270M 114760 77421 0 2605 166 15:40:17
ADSL Link Downstream Upstream
Connection Speed 3840 kbps 448 kbps
Line Attenuation 56.0 db 31.0 db
Noise Margin 9.0 db 18.0 db
# adslctl info --stats
adslctl: ADSL driver and PHY status
# adslctl info --stats
adslctl: ADSL driver and PHY status
Status: ShowtimeRetrain Reason: 1
Channel: INTR, Upstream rate = 448 Kbps, Downstream rate = 3840 Kbps
Link Power State: L0
Mode: G.DMT
Channel: Interleave
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 9.1 18.0
Attn(dB): 56.0 31.0
Pwr(dBm): 19.4 12.1
Max(Kbps): 4384 1008
Rate (Kbps): 3840 448
G.dmt framing
K: 121(0) 15
R: 16 16
S: 1 8
D: 32 4
ADSL2 framing
MSGc: 1 1
B: 142 15
M: 1 1
T: 1 1
R: 0 0
S: 1.0000 1.0000
L: 1144 128
D: 1 1
Counters
SF: 152278 152220
SFErr: 1 0
RS: 10354934 1293870
RSCorr: 12062 1
RSUnCorr: 12 0
HEC: 1 0
OCD: 0 0
LCD: 0 0
Total Cells: 23445357 0
Data Cells: 1531321 0
Drop Cells: 0
Bit Errors: 0 0
ES: 3029 0
SES: 395 0
UAS: 23 0
AS: 2589
INP: 0.00 0.00
PER: 1.75 1.75
delay: 0.25 0.25
OR: 32.00 32.00
Bitswap: 0 0
Total time = 1 days 4 hours 6 min 2 sec
SF = 152278
CRC = 1
LOS = 1
LOF = 9
ES = 3029
Latest 1 day time = 4 hours 6 min 2 sec
SF = 152278
CRC = 1
LOS = 1
LOF = 9
ES = 921
Latest 15 minutes time = 6 min 2 sec
SF = 21299
CRC = 0
LOS = 0
LOF = 0
ES = 0
Previous 15 minutes time = 15 min 0 sec
SF = 52923
CRC = 0
LOS = 0
LOF = 0
ES = 0
Previous 1 day time = 24 hours 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 2108
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF = 52982
CRC = 0
LOS = 0
LOF = 0
ES = 0
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF = 25074
CRC = 1
LOS = 1
LOF = 9
ES = 16
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 49
Showtime Drop Reason: 1
Last Retrain Reason: 1
#
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>> by sheer fluke we noticed that when it happens the little screen bottom right of monitor (Vista) shows a 'yellow warning triangle followed by a redX on it a few seconds later it will get the blue connected symbol again.
I dont run vista.. but is that the wireless networking icon?
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It's just networks in general bundled together.
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Hi
these look a bit odd to me
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF = 52982 ==================================== OK normal
CRC = 0
LOS = 0
LOF = 0
ES = 0
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF = 25074 ++++++++++============================== ??
CRC = 1
LOS = 1
LOF = 9
ES = 16
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF = 0 ===============================================??
CRC = 0
LOS = 0
LOF = 0
ES = 49
Perhaps one of the GURUS can help?
Regards Jeff
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I don't under stand any of the stats that I got out by telnet but it mentions ADSL2 framing and I am on just old-fashioned ADSL Max :-\
That is 2 routers now that I have used and both seem to drop something and now we chanced to notice it is the connection I am totally lost,checked in the router and it is set for 1500 MTU and idletime out is 0 set it to VC as I think it should be..
Could it be my phone line playing up still with that voltage error ?
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Hi Mist,
DLM does sometimes seems to be much more sensitive, and hence prone to raising the target margin, if a line has previously had it's margin raised and then reduced.
As you'll probably have noticed, some of us on the forum are anxious to try and figure out how DLM actually works as BT don't document it anywhere, and any extra input would be welcomed. With that in mind, do you by any chance know what time of day it was that the target got raised again?
I ask that question of interest in case it reflects my own experience, where my taget seemed to go back up exactly 48 hours (maybe to the minute) after my ISP got it reduced. If yours, also, was raised after exactly 48 hours then I'd be inclined to assume it's no co-incidence, and might allow us to make further guesses about the workings of DLM.
Sorry that none of above helps you much to figure out what's up (if anything) with your line. The thing is, such a high attenuation means that the signal presented to your router is very tiny. Such a tiny signal is more easily overwhelmed by the normal and unnavoidable 'spikes' of noise that occur on any phone line, and hence longer lines do tend do need higher noise margins. I'm inclined to suggest that operating a 56dB line at 6dB SNR is probably pushing things. But then again, if it's been running that way with good stability for a long time then I don't see why it shouldn't continue to do so...? :-\
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Hi sevenlayermuddle,
Trying to read routerstats the timings look as follows.
First jump to 9db was on Saturday 25th July around 11.17am. after running at 6db with no problems whatsoever but noticable that BT throughput was low for a few days/weeks previously in the evenings.
Thursday 13th August SNR dropped to 6db approx. 15.20pm
Saturday 15th August SNR raised to 9db approx 15.37pm.
Now see m,y ISP has PPP issues whatever that may mean. ::) Told you I am not techy but issues seem to have been ongoing for me since I changed to the ISP
Edited to add info. in case of help to you all, My Bt profile always had set days so it seemed on which it updated always 5 days exactly even after a large drop due to a storm. Also I keep system all running 24/7 so last time was awaiting the 336 WAN up hours to see if SNR dropped automatically but BT did a resynch at just under 300 uptime which I see has been the sequence reported on other forums.
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Thursday 13th August SNR dropped to 6db approx. 15.20pm
Saturday 15th August SNR raised to 9db approx 15.37pm.
Hmm, that's pretty darned close to 48 hours and so it pretty much reflects my experience. It's almost as if, when an ISP requests a manual override to the target margin, it gets automatically reviewed again after 48 hours, sometimes bouncing right back to where it was. In my case, I'm afraid, the target margin then stayed raised forever (at least, about a year now and couinting). Then again, it's not exactly 48 hours (a few minutes adrift) so may just be pure co-incidence :-\
I have to say that a sync speed of 4300, with 9dB margin as shown below, on a 56dB line is actually doing quite well, you know. I also have a 56dB attenuation, and I 'tweak' my own margin to overcome DLM's inapropriate target of 15dB. I know that if I allow it to sync with a 6dB margin (I only recently discovered I could do that!) it will soon become unstable, so I normally aim for at least a 9dB initial margin.
Still, it sounds like your line's not as 'good' as it used to be. Maybe some other people on the forum with a better idea of what's 'normal' could comment on your error rates, and whether there's likely to be an ongoing fault on your phone line, or whether it's other interference?
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Well when the 9db noise margin cutin on Saturday it synched at 3840kbps and has firmly stuck at that ever since.
I once had a 'stuck profile' at 2 megs and this is how it feels now as if someone has said you will stick at a 3 meg profile not even 3500...when BT did all the work etc on my line just under 2 years ago they said then it would run at 4 meg and it did... :(
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Well when the 9db noise margin cutin on Saturday it synched at 3840kbps and has firmly stuck at that ever since.
Ooops sorry, I think I must have looked at the 'max' figure rather than the rate. I've an optician's appointment for an eye test this week, and not before time it seems :)
That being the case, the most alarming thing about your stats for me is...
ES: 3029 0
SES: 395 0
UAS: 23 0
AS: 2589
... How can it be that the number of Errored Seconds (ES) exceeds the cumulative total of Available Seconds (AS) and Unavailable seconds)? Am I missing something?
Regardless of that anomaly, your ES count for the 15 minute slots do look quite high to me, and that SES (Severe ES) count is high too if the total uptime is to be believed.
I'm inclined to hazard a guess that there may be a remaining fault with your line, despite the earlier Openreach fix. However, be wary of calling them out again unless you can get some convincing evidence, else they'll end up billing you for 'no fault found'.
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Thank you for your help, it is much appreciated.
I don't understand any of the stats beyond the most basic ones :( and have only just learnt how to get them. I found the following which I had taken on the 14th august after the SNR went to 6db I think it shows lots of errors.
I also think it is the line at still wonky and we are seriously discussing this evening changing ISP to a company that will take on lines like mine with a possible fault.
# adslctl info --stats
adslctl: ADSL driver and PHY status
Status: ShowtimeRetrain Reason: 1
Channel: FAST, Upstream rate = 448 Kbps, Downstream rate = 4448 Kbps
Link Power State: L0
Mode: G.DMT
Channel: Fast
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 5.9 18.0
Attn(dB): 56.0 31.0
Pwr(dBm): 19.4 12.2
Max(Kbps): 4480 940
Rate (Kbps): 4448 448
G.dmt framing
K: 140(0) 15
R: 0 0
S: 1 1
D: 1 1
ADSL2 framing
MSGc: 1 1
B: 119 15
M: 2 8
T: 1 1
R: 16 16
S: 2.1333 9.0000
L: 960 128
D: 16 4
Counters
SF: 3956657 3956655
SFErr: 2346 11
RS: 0 0
RSCorr: 0 0
RSUnCorr: 0 0
HEC: 1505 5
OCD: 10 0
LCD: 0 0
Total Cells: 705625927 0
Data Cells: 3277134 0
Drop Cells: 0
Bit Errors: 0 0
ES: 1480 0
SES: 27 0
UAS: 47 0
AS: 67264
INP: 1.06 2.00
PER: 1.86 1.96
delay: 8.53 9.00
OR: 30.00 28.44
Bitswap: 0 0
Total time = 1 days 23 hours 20 min 53 sec
SF = 3956657
CRC = 2346
LOS = 2
LOF = 18
ES = 1480
Latest 1 day time = 23 hours 20 min 53 sec
SF = 3956657
CRC = 2346
LOS = 2
LOF = 18
ES = 1398
Latest 15 minutes time = 5 min 53 sec
SF = 20768
CRC = 3
LOS = 0
LOF = 0
ES = 3
Previous 15 minutes time = 15 min 0 sec
SF = 52982
CRC = 16
LOS = 0
LOF = 0
ES = 15
Previous 1 day time = 24 hours 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 82
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF = 52923
CRC = 16
LOS = 0
LOF = 0
ES = 14
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF = 52923
CRC = 22
LOS = 0
LOF = 0
ES = 21
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF = 52923
CRC = 10
LOS = 0
LOF = 0
ES = 10
Showtime Drop Reason: 1
Last Retrain Reason: 1
#
#
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I also think it is the line at still wonky and we are seriously discussing this evening changing ISP to a company that will take on lines like mine with a possible fault.
Hi Mist,
The trouble is, changing ISP won't necessarily make any difference to the sync speed you obtain. It could also be argued that the more unscrupulous ISPs will be the very ones that are willing to promise you the earth to get your signature on the dotted line, but then provide you with no support at all.
It looks to me like your line was a little unstable when it synced at 4448/6dB, and that may be the reason your SNR target got raised again. However, the subsequent resync at 3840/9dB should have led to a reduction in error stats whereas - correct me if I'm wrong - you seem to have seen an increase in errors? That would suggest that something has deteriorated in the intervening time. We know that the line had a fault in the very recent past so, unless it's a co-incidence, it's tempting to think the line fault has returned again. Proving it's another matter.
I'm no expert in the area, but I'm not sure you've got enough evidence to accuse BT of a line fault. Unless, of course, the quiet-line-test proves otherwise? When talking to BT, be very careful not to get landed with a charge for an engineer's call out with 'No fault found'. Still, have you asked BT if they're able to test your line again, just to confirm the fault is still cleared? I'd hope they'd not charge you just for a line test, but I'm not sure - make you could ask them.
I'm even less of an expert when it comes to REIN issues, but I'd have thought REIN could also be a contributing factor. Maybe a neighbour has recently changed someting, (say, a new fridge), that generates more noise than previously. Unless such interference is excessive there may not be much you could do about it (I know you've already optimised everything that you can).
I've dug myself in beyond my comfort zone here, so I'm hoping some of the Gurus will chip in and correct me if I'm giving bad advice! :-[
edited to remove some annoying typos.
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The last set of stats show that you have had interleaving turned off and have gone to FAST or fastpath mode. Interleaving (http://www.kitz.co.uk/adsl/interleaving.htm) is a form of error correction that helps tolerate noise, and with your line length, and unless you are playing latency sensitive games, would be best turned on again.
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Hi Orainsear,
Mist will have to correct me if I'm wrong, but I think the most recently posted stats are not the latest stats, they were captured on 14th August, and posted to illustrate the situation that existed when the target margin was 6dB.
The stats posted (and obtained) on 15th August seem to show
"Channel: Interleave".
I assume that means that interleaving has already been turned back on again? Interleaving may have got re-enabled at the same time as the target margin got raised, as I believe that's another of DLM's automatic reactions to unstable lines.
- 7LM
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Ah yes I see. Most likely as you suggest that interleaving has been turned on again automatically.
@ mist - can you post another set of current stats to see how your line is a the moment?
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System Up Time 06:47:39
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 15100 20520 0 288 1434 03:56:06
LAN 10M/100M 126248 84368 0 5413 451 06:47:29
WLAN 11M/54M/270M 33 0 0 0 0 06:44:15
ADSL Link Downstream Upstream
Connection Speed 3904 kbps 448 kbps
Line Attenuation 56.0 db 31.0 db
Noise Margin 9.1 db 18.0 db
Status: ShowtimeRetrain Reason: 0
Channel: INTR, Upstream rate = 448 Kbps, Downstream rate = 3904 Kbps
Link Power State: L0
Mode: G.DMT
Channel: Interleave
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 9.1 18.0
Attn(dB): 56.0 31.0
Pwr(dBm): 19.5 12.1
Max(Kbps): 4480 1012
Rate (Kbps): 3904 448
G.dmt framing
K: 123(0) 15
R: 16 16
S: 1 8
D: 32 4
ADSL2 framing
MSGc: 1 1
B: 123 15
M: 1 8
T: 1 1
R: 16 16
S: 1.1290 9.0000
L: 992 128
D: 32 4
Counters
SF: 1429746 1429766
SFErr: 27 2
RS: 97222758 12152008
RSCorr: 13015 25
RSUnCorr: 313 0
HEC: 25 0
OCD: 0 0
LCD: 0 0
Total Cells: 223795838 0
Data Cells: 2217109 0
Drop Cells: 0
Bit Errors: 0 0
ES: 22 0
SES: 0 0
UAS: 12 0
AS: 24306
INP: 2.06 2.00
PER: 1.97 1.96
delay: 9.03 9.00
OR: 28.34 28.44
Bitswap: 0 0
Total time = 6 hours 45 min 30 sec
SF = 1429746
CRC = 27
LOS = 0
LOF = 0
ES = 22
Latest 1 day time = 6 hours 45 min 30 sec
SF = 1429746
CRC = 27
LOS = 0
LOF = 0
ES = 22
Latest 15 minutes time = 30 sec
SF = 1770
CRC = 0
LOS = 0
LOF = 0
ES = 0
Previous 15 minutes time = 15 min 0 sec
SF = 52923
CRC = 1
LOS = 0
LOF = 0
ES = 1
Previous 1 day time = 0 sec
SF = 0
CRC = 0
LOS = 0
LOF = 0
ES = 0
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF = 52923
CRC = 0
LOS = 0
LOF = 0
ES = 0
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF = 52982
CRC = 1
LOS = 0
LOF = 0
ES = 1
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF = 52923
CRC = 1
LOS = 0
LOF = 0
ES = 1
Showtime Drop Reason: 0
Last Retrain Reason: 0
#
#
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I also think it is the line at still wonky and we are seriously discussing this evening changing ISP to a company that will take on lines like mine with a possible fault.
Hi Mist,
The trouble is, changing ISP won't necessarily make any difference to the sync speed you obtain. It could also be argued that the more unscrupulous ISPs will be the very ones that are willing to promise you the earth to get your signature on the dotted line, but then provide you with no support at all.
It looks to me like your line was a little unstable when it synced at 4448/6dB, and that may be the reason your SNR target got raised again. However, the subsequent resync at 3840/9dB should have led to a reduction in error stats whereas - correct me if I'm wrong - you seem to have seen an increase in errors? That would suggest that something has deteriorated in the intervening time. We know that the line had a fault in the very recent past so, unless it's a co-incidence, it's tempting to think the line fault has returned again. Proving it's another matter.
I'm no expert in the area, but I'm not sure you've got enough evidence to accuse BT of a line fault. Unless, of course, the quiet-line-test proves otherwise? When talking to BT, be very careful not to get landed with a charge for an engineer's call out with 'No fault found'. Still, have you asked BT if they're able to test your line again, just to confirm the fault is still cleared? I'd hope they'd not charge you just for a line test, but I'm not sure - make you could ask them.
I'm even less of an expert when it comes to REIN issues, but I'd have thought REIN could also be a contributing factor. Maybe a neighbour has recently changed someting, (say, a new fridge), that generates more noise than previously. Unless such interference is excessive there may not be much you could do about it (I know you've already optimised everything that you can).
I've dug myself in beyond my comfort zone here, so I'm hoping some of the Gurus will chip in and correct me if I'm giving bad advice! :-[
edited to remove some annoying typos.
You are being the most wonderful help, especially to someone who doesn't understand these stats.
This morning the little monitor thingy on my PC monitor again showed fleetingly the yellow warning triangle followed by the red cross to symbolise loss of connection.
I decided just in case to do a factory re-set and enter everything again manually.
The quiet line test seems errrmm quiet but it was intermittent previously.
I e-mailed early today for my MAC and received it within 5 minutes. This was based on careful deliberation and the knowledge that my line appeared excellent until I changed ISP in June, plus being told by the isp that routerstats was no good to use which fact has been troubling me greatly.
I phoned aaisp and asked if they could possibly help, I do understand that my line is very long but based on the fact even I with no knowledge as such can see loads of errors and could not understand the fast/interleavibng business either
I did tell them that I had had phone line problems voltage error and the isp had said they had seen that battery error..so would they take my MAC based on possible problems.
They said yes and would try to help. They are aware that all my line etc was sorted out and replaced etc less than 2 years ago. Those squirrels can cause a lot of damage on countryside overhead lines with trees growing around them. ;D The electric cables for the horses were removed a few months ago butaround half a mile away on the route is a rather large substation....
I know i can never have good speeds etc but would like a good 'plod' along preferably at the best rate possible, still scratching my head as to how it went so pear-shaped on migration in June on old fashioned ADSLMax not the new system.
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Ah yes I see. Most likely as you suggest that interleaving has been turned on again automatically.
@ mist - can you post another set of current stats to see how your line is a the moment?
I have got the stats from the Netgear and used that Telnet thing to get the stats, sorry but those are thec only ones I know how to use.
I have now used 2 routers and tried 3 x RJ11's, plus am directly in the special BT filtered faceplate with no extensions etc. oh and power cable is now draped most inelegantly across the desk going the opposite direction to the ADSL and ethernet wires..
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revived this thread to say Thank you to all and show the very happy outcome
REIN mysteriously disappeared as line was changed to new ISP.....then I heard more noise on my phone line.. :( that took a lot of sorting out and BT told me that yes their testing did show a voice problem.Yes well I could hear it, the echo of others on the line...a steady deterioration
Good news followed after a very kindly BT linesman spent 5 whole hours last Saturday sorting out my line, he found a battery error something to do with water in a joint. now hopefully repaired, changed to a Zyxel router as well pre-configured by the ISP to suit their system and hey presto. the following are my stats now, speedchecker run at 3.47 pm today.. :)
noise margin upstream: 18 db
output power downstream: 20 db
attenuation upstream: 31 db
noise margin downstream: 6 db
output power upstream: 12 db
attenuation downstream: 58 db
Download speedachieved during the test was - 3484 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :4896 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 4000 Kbps
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That certainly appears to be a good result.
Just out of interest, who were / are the old and new ISPs.
TTFN
toulouse
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>> REIN mysteriously disappeared as line was changed to new ISP.
Weird..
>> .then I heard more noise on my phone line..
but in a way it was good because at least that gives something to act on.
Noisy line > water on the joint... that will cause erratic adsl. Touch wood this is it all sorted now :)
Thats a very good sync speed for such a long line. Due to line length you can still expect to see some sort of fluctuation in sync, but that is looking good.
Long may it continue. ;D