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Internet stops working when SNR drops below 6dB

myredhotcar
Grafter
Posts: 457
Registered: 06-11-2013

Internet stops working when SNR drops below 6dB

Further to this problem things have been OK until recently; pages would not load or take forever, torrents would stall and all intermittently. I checked the SNR using DSLstats and it is clear that each time the SNR drops below 6dB I get the issues. Unlike with my previous two routers the router doesn't lose the plot and doesn't reset itself. As I have the DGTeam firmware (DG834GT) installed I raised the SNR percentage slider to 110% and the issues went away. As a result it seems DLM has possibly reduced my SNR more as today I had to increase the slider to 115%.
I may be reaching the wrong conclusion but my line clearly seems incapable of handling anything below around 7db. My DL speed was very high at one point but that is moot if I cannot use the line. I would rather have a slightly slower but stable line. but I do not want to lose UL speed. I can manage with 9-10 DL.
What are my options? I'd rather not be messing about with the SNR percentage as it seems like an inelegant solution. Can you tell DLM not to allow my SNR to be lower than 7.5dB? If not can you override DLM at your end, can there be such a thing as a preset profile?
I would appreciate it if you could sort it for me as soon as you get the chance. If there is more than one option to resolve the issue please advise me as to what options there are.
And please no more fault checkers. I completed one with my last issue, can that be used? The issue appears identical but this router doesn't fall over each time. Many thanks  Wink
Sat, 2000-01-01 00:01:06 - <HTTP> Administrator login successful - IP:192.168.0.3
Sat, 2000-01-01 00:01:06 - Initialize LCP.
Sat, 2000-01-01 00:01:07 - LCP is allowed to come up.
Sat, 2000-01-01 00:01:08 - CHAP authentication success
Sat, 2000-01-01 00:01:08 - <HTTP> Administrator login successful - IP:192.168.0.3
Sat, 2000-01-01 00:01:10 - <TELNET> Administrator login successful - IP:192.168.0.3
Tue, 2014-01-07 03:43:54 - <NTP> Receive NTP Reply from 206.16.42.153
Tue, 2014-01-07 03:46:01 - <HTTP> Administrator login successful - IP:192.168.0.3
Tue, 2014-01-07 03:46:47 - <TELNET> Administrator login successful - IP:192.168.0.3
Tue, 2014-01-07 04:21:48 - <NTP> Local NTP clock is now synced
Tue, 2014-01-07 04:22:17 - <TELNET> Administrator login successful - IP:192.168.0.3
Tue, 2014-01-07 03:42:23 - Router start up
Tue, 2014-01-07 04:32:47 - <TELNET> Administrator login successful - IP:192.168.0.3
Tue, 2014-01-07 18:48:07 - <HTTP> Administrator login successful - IP:192.168.0.3
Tue, 2014-01-07 20:48:16 - <HTTP> Administrator login successful - IP:192.168.0.3
Wed, 2014-01-08 18:45:35 - Initialize LCP.
Wed, 2014-01-08 18:45:35 - LCP is allowed to come up.
Wed, 2014-01-08 18:45:36 - CHAP authentication success
Wed, 2014-01-08 18:55:45 - Initialize LCP.
Wed, 2014-01-08 18:55:45 - LCP is allowed to come up.
Wed, 2014-01-08 18:56:45 - Initialize LCP.
Wed, 2014-01-08 18:56:46 - LCP is allowed to come up.
Wed, 2014-01-08 18:57:46 - Initialize LCP.
Wed, 2014-01-08 18:57:46 - LCP is allowed to come up.
Wed, 2014-01-08 18:58:46 - Initialize LCP.
Wed, 2014-01-08 18:58:46 - LCP is allowed to come up.
Wed, 2014-01-08 18:59:46 - Initialize LCP.
Wed, 2014-01-08 18:59:46 - LCP is allowed to come up.
Wed, 2014-01-08 19:00:46 - Initialize LCP.
Wed, 2014-01-08 19:00:46 - LCP is allowed to come up.
Wed, 2014-01-08 19:01:09 - CHAP authentication success
Wed, 2014-01-08 19:01:39 - <NTP> Receive NTP Reply from 209.249.181.23
Wed, 2014-01-08 19:40:22 - <NTP> Local NTP clock is now synced
Thu, 2014-01-09 01:13:50 - <NTP> Receive NTP Reply from 209.249.181.23
Thu, 2014-01-09 02:23:01 - <NTP> Receive NTP Reply from 209.249.181.23
Thu, 2014-01-09 03:51:40 - <TELNET> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:01:31 - <HTTP> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:01:40 - <TELNET> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:02:40 - <TELNET> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:02:58 - LCP down.
Thu, 2014-01-09 04:03:08 - Initialize LCP.
Thu, 2014-01-09 04:03:08 - LCP is allowed to come up.
Thu, 2014-01-09 04:03:10 - CHAP authentication success
Thu, 2014-01-09 04:03:10 - <TELNET> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:03:33 - <NTP> Receive NTP Reply from 209.249.181.23
Thu, 2014-01-09 04:03:40 - <TELNET> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:05:19 - LCP down.
Thu, 2014-01-09 04:05:29 - Initialize LCP.
Thu, 2014-01-09 04:05:29 - LCP is allowed to come up.
Thu, 2014-01-09 04:05:31 - CHAP authentication success
Thu, 2014-01-09 04:05:40 - <TELNET> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:06:01 - <NTP> Receive NTP Reply from 209.249.181.23
Thu, 2014-01-09 04:06:10 - <TELNET> Administrator login successful - IP:192.168.0.3
Thu, 2014-01-09 04:10:23 - <HTTP> Administrator login successful - IP:192.168.0.3

adslctl info --stats
adslctl: ADSL driver and PHY status
Status: ShowtimeRetrain Reason: 8000
Channel: FAST, Upstream rate = 888 Kbps, Downstream rate = 10999 Kbps
Link Power State: L0
Mode:                  ADSL2+
Channel:                Fast
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):      7.4            10.0
Attn(dB):      38.5            23.4
Pwr(dBm):      0.0            12.8
Max(Kbps):      12768          888
Rate (Kbps):    10999          888
                        G.dmt framing
K:              124(0)          14
R:              6              16
S:              2              8
D:              64              8
                        ADSL2 framing
MSGc:          54              10
B:              123            13
M:              2              8
T:              3              9
R:              6              16
S:              0.7195          4.0000
L:              2824            256
D:              64              8
                        Counters
SF:            43737          39286
SFErr(CRCErr):  0              0
RS:            3936398        707155
RSCorr:        515            0
RSUnCorr:      0              0
HEC:            0              0
OCD:            0              0
LCD:            0              0
Total Cells:    18384663                1215768
Data Cells:    3254308        209131
Drop Cells:    0
Bit Errors:    0              0
ES:            1420            0
SES:            4              0
UAS:            141            0
AS(Uptime):    709
INP:            0.54            2.00
PER:            16.18          18.00
delay:          11.51          8.00
OR:            29.64          7.11
Bitswap:        86              7
Total uptime:  176357
Total time = 1 days 1 hours 2 min 50 sec
SF  = 10998718
CRC = 3382
LOS = 0
LOF = 0
ES  = 1420
Latest 1 day time = 1 hours 2 min 50 sec
SF  = 225251
CRC = 31
LOS = 0
LOF = 0
ES  = 11
Latest 15 minutes time = 2 min 50 sec
SF  = 10470
CRC = 0
LOS = 0
LOF = 0
ES  = 0
Previous 15 minutes time = 15 min 0 sec
SF  = 52680
CRC = 0
LOS = 0
LOF = 0
ES  = 0
Previous 1 day time = 24 hours 0 sec
SF  = 5388611
CRC = 1620
LOS = 0
LOF = 0
ES  = 653
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF  = 56236
CRC = 8
LOS = 0
LOF = 0
ES  = 4
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF  = 49752
CRC = 16
LOS = 0
LOF = 0
ES  = 3
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF  = 56113
CRC = 7
LOS = 0
LOF = 0
ES  = 4
Showtime Drop Reason:  8000
Last Retrain Reason:    8000
#

EDIT: missing data
22 REPLIES
ian007jen
Rising Star
Posts: 392
Thanks: 4
Fixes: 2
Registered: 06-09-2007

Re: Internet stops working when SNR drops below 6dB

Quote
Pwr(dBm):      0.0
on downstream.
May be a problem with your router, have you another to use to rule this out.
Ian
myredhotcar
Grafter
Posts: 457
Registered: 06-11-2013

Re: Internet stops working when SNR drops below 6dB

Hi ian007jen
Thanks for the input, this is actually the 3rd router since joining PlusNet just before Christmas, I linked to my original thread (which has stats from all 3 routers). The last router (WBR T2) also gave the same readings on downstream Pwr(dBm) as per this post. At least 2 of the 3 routers reported the same dB reading.
My original problem was that the router would cut out and restart if the SNR dropped below 6dB; the second router did a better job of holding the line, this current router better again. Once I got this router up and running DLM slowly dropped the SNR margin and it wasn't until it got down to the 6dB level I started hitting problems. I am plugged directly into the test socket.
With my limited router knowledge I can only assume my flaky line cannot handle such a low SNR.
To reiterate my question can DLM be overridden or 'told' not to allow my SNR to drop below 7.5-8dB?
Community Veteran
Posts: 1,617
Thanks: 22
Registered: 29-06-2010

Re: Internet stops working when SNR drops below 6dB

They should be able to set it at a target of 9dB - it goes up in 3dB steps.
myredhotcar
Grafter
Posts: 457
Registered: 06-11-2013

Re: Internet stops working when SNR drops below 6dB

Hi jaggies thanks for the input
That seems ideal, I will lose a bit of speed but the connection will be stable. Things were going really well until DLM dropped the SNR too far.
In theory should DLM see the issues I am having and automatically increase the SNR or are there limitations/flaws with the system?
Cheers
ian007jen
Rising Star
Posts: 392
Thanks: 4
Fixes: 2
Registered: 06-09-2007

Re: Internet stops working when SNR drops below 6dB

Right..
I would
1. Ask for a line reset, and if the same thing happens again
2. ask for a margin of 9 dB
In a perfect world you should be able to report this as a fault but I think the odds of Plusnet (openreach) fixing it may be small
Ian
Community Veteran
Posts: 1,136
Thanks: 2
Registered: 30-07-2007

Re: Internet stops working when SNR drops below 6dB

Do you have wired extensions coming from your master socket?
I ask because I was experiencing similar issues, my SNR would drop to 3, I'd sync at a nice high speed but the bell wire on my 6 extensions was causing so much interference it was unusable at those speeds, with the same symptoms (Stalled downloads (torrents and http)).
I tested for a while in just the test socket and everything was nice and stable and at the higher speeds, and I bought and fitted an iPlate (although if you prefer, removing the bell wire from the extension sockets should have the same effect).
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)
myredhotcar
Grafter
Posts: 457
Registered: 06-11-2013

Re: Internet stops working when SNR drops below 6dB

Thanks for the replies!
@ Ian: The line definitely seems noisy if nothing else and maybe not all that reliable. I've made a request for the issue to be looked at but I fear a margin of 6dB is unattainable with my line, unless the wet weather has exacerbated the issues or something, simply as it was where I had issues before. Hopefully if I do have to move to 9dB my speed won't be too bad, I've not yet streamed full HD but if it can do that I can manage.
@ avatastic: There was an extension fitted when I moved in but it was fitted when the previous tenant had Sky BB and was a simple plug in extension cable, I removed it when I moved in so I guess no? My sync speed (according to DSLstats) was slightly over 11Mb at one point but torrents were painful and kept dropping to 0; at a slightly higher SNR margin some torrents reach 1.02Mb (according to transmission). I've been meaning to get an iPlate though, do they just plug in or would I need to connect wires?
Community Veteran
Posts: 1,136
Thanks: 2
Registered: 30-07-2007

Re: Internet stops working when SNR drops below 6dB

Assuming you have an NTE5 master socket, an iPlate is installed by removing the lower part, plugging the iPlate in to the test socket and then the original lower half in to the iPlate, no need to remove or punch down new wires.
The iPlate isn't filtered so you'll still need an ADSL filter in the socket.
Kitz has some information on this.
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)
myredhotcar
Grafter
Posts: 457
Registered: 06-11-2013

Re: Internet stops working when SNR drops below 6dB

Cheers avatastic will get that done. Socket is right next to the front door and the dog has a habit of knocking the cable as it protrudes a little so boxing it all off too.
Could a member of the DCT please take a look at this thread; I tried the report a fault tool and I keep getting errors, the absurdity. I'm loathe to phone due to waiting times and I am also unsure if this is something they can help with.
SNR percentage slider currently at 122%.
EDIT: additional info
adslctl info --stats
adslctl: ADSL driver and PHY status
Status: ShowtimeRetrain Reason: 8000
Channel: FAST, Upstream rate = 888 Kbps, Downstream rate = 10354 Kbps
Link Power State: L0
Mode:                   ADSL2+
Channel:                Fast
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
               Down            Up
SNR (dB):       7.9             9.8
Attn(dB):       38.5            23.3
Pwr(dBm):       0.0             12.9
Max(Kbps):      12152           888
Rate (Kbps):    10354           888
                       G.dmt framing
K:              123(0)          14
R:              6               16
S:              2               8
D:              64              8
                       ADSL2 framing
MSGc:           51              10
B:              122             13
M:              2               8
T:              3               9
R:              6               16
S:              0.7581          4.0000
L:              2659            256
D:              64              8
                       Counters
SF:             4732193         4260625
SFErr(CRCErr):  792             0
RS:             404602568               3676810
RSCorr:         89780           61
RSUnCorr:       23534           0
HEC:            725             0
OCD:            2               0
LCD:            0               0
Total Cells:    1872831070              1671880
Data Cells:     43134932                18783
Drop Cells:     0
Bit Errors:     0               0
ES:             4102            0
SES:            16              6
UAS:            177             0
AS(Uptime):     76692
INP:            0.57            2.00
PER:            16.20           18.00
delay:          12.13           8.00
OR:             28.13           7.11
Bitswap:        2602            1953
Total uptime:   570728
Total time = 1 days 14 hours 36 min 32 sec
SF  = 35352904
CRC = 9292
LOS = 0
LOF = 0
ES  = 4102
Latest 1 day time = 14 hours 36 min 32 sec
SF  = 3245156
CRC = 651
LOS = 0
LOF = 0
ES  = 252
Latest 15 minutes time = 6 min 32 sec
SF  = 24199
CRC = 12
LOS = 0
LOF = 0
ES  = 7
Previous 15 minutes time = 15 min 0 sec
SF  = 55515
CRC = 28
LOS = 0
LOF = 0
ES  = 11
Previous 1 day time = 24 hours 0 sec
SF  = 5331938
CRC = 1204
LOS = 0
LOF = 0
ES  = 557
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF  = 55516
CRC = 16
LOS = 0
LOF = 0
ES  = 9
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF  = 55578
CRC = 6
LOS = 0
LOF = 0
ES  = 4
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF  = 55515
CRC = 12
LOS = 0
LOF = 0
ES  = 6
Showtime Drop Reason:   8000
Last Retrain Reason:    8000
#
Community Veteran
Posts: 26,718
Thanks: 931
Fixes: 10
Registered: 10-04-2007

Re: Internet stops working when SNR drops below 6dB

You would probably do better filling a filtered face plate rather than an iPlate.
Have you tried with interleaving on? It may keep working better when the noise margin drops.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
myredhotcar
Grafter
Posts: 457
Registered: 06-11-2013

Re: Internet stops working when SNR drops below 6dB

Hi Jelv
Would you recommend a particular product or would any do?
According to DSLstats interleaving is on (unless I am misunderstanding you) is this what you mean? If not what are the steps I would need to take?
Community Veteran
Posts: 26,718
Thanks: 931
Fixes: 10
Registered: 10-04-2007

Re: Internet stops working when SNR drops below 6dB

That's odd because your previous post shows the channel as fast which isn't interleaved. Changing the interleaving has to be done by Plusnet.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Community Veteran
Posts: 1,617
Thanks: 22
Registered: 29-06-2010

Re: Internet stops working when SNR drops below 6dB

Upstream interleaving is on, hence the 888 upstream speed.
Community Veteran
Posts: 1,136
Thanks: 2
Registered: 30-07-2007

Re: Internet stops working when SNR drops below 6dB

Quote from: jelv
That's odd because your previous post shows the channel as fast which isn't interleaved. Changing the interleaving has to be done by Plusnet.

I thought on 21CN interleaving has 3 settings. On, Off and Auto and DLM can switch it on if it feels like it it will benefit the line.
The 64 figure quoted from routerstats would suggest (based on information skimmed from Kitz) Downstream Interleaving is indeed on.
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)