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SNR has suddenly increased and speed dropped

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robski1
Rising Star
Posts: 132
Thanks: 7
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Registered: ‎06-11-2008

SNR has suddenly increased and speed dropped

I have been with Globalnet, Madasafish and PlusNet for many years and my connection has always been rock solid with very few disconnections. Download SNR 3 and speeds around 13 Mbps any time of the day. My BT profile has always been in the high 13's.

Over the last few days I have had several disconnections, usually late at night when I have not been using my PC.

My SNR has now increased to 9.1 and my speed dropped to 10.3 Mbps. The BT profile and the PlusNet transfer speed have dropped as well.

Nothing in the house has changed that could effect things.

Any suggestions on how to get back to the speed I had before?

My router is the Plusnet supplied technicolor 582n

36 REPLIES
hitchhiker43
Aspiring Pro
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Registered: ‎06-07-2016

Re: SNR has suddenly increased and speed dropped

The DLM software thinks that your line is impaired in some way so has been progressively increasing your target snr resulting in the speed drop, you may find it has turned on interleaving as well. You don't say if you are running adsl or superfast ?

Tp-link W8960n on longgggggggg line!
robski1
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Registered: ‎06-11-2008

Re: SNR has suddenly increased and speed dropped

Hi hitchhiker43.

I am on adsl and I think that interleaving has always been on.

The router has now started to reboot it's self during the day as well as at night.

I'm wondering if it is the router giving the problems.

I have checked the phone line and there is no noise when doing the silence test.

hitchhiker43
Aspiring Pro
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Re: SNR has suddenly increased and speed dropped

Hi Rob,

I am suprised one of the staff here has not got back to you, it seems the DLM has got it's knickers in a twist as usual and needs resetting to restore your line to 6dB target snr and then your rate will restore to wha it was before.  As I said some impairments could cause this but as you have not changed anything it's up to Pnet to investigate why there is a problem, they have various tools and can tell you what has been happening on your line. Another thing you could do is install DSLSTATS and monitor it yourself, it takes a while to understand what a typical day looks like on a line but after a while of usage you will be able to spot problems yourself and in particular changes from the norm by keeping a few records.

I hope someone from Pnet eventually notices your post, if not raise a fault ticket, just answer the trick questions in the broadband fault thingy here https://portal.plus.net/apps/kbdfaults/question carefully and you get to raise a ticket....goodluck

Roger

Tp-link W8960n on longgggggggg line!
robski1
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Posts: 132
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Registered: ‎06-11-2008

Re: SNR has suddenly increased and speed dropped

Thanks Roger,

I had forgotten about the fault checker.

I'll see if any PlusNet guys get back to me, if not I'll give the fault checker a go.

Rob.

Stumpy21
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Registered: ‎13-06-2011

Re: SNR has suddenly increased and speed dropped

robski1

I think the DLM is not working as we are told it should. Well not on my exchange - maybe yours too.

Over 2 months connection at 3db SNR. I had a red internet light on my router so did a reboot to cure it. Worked OK and SNR still at 3db, 2 days later the connection did a resync when the SNR fell to less than 2db and synced with a 6dB SNR?Huh

I thought you could do reboots/resyncs and as long as you did them an hour or so apart it shouldn't affect your SNR?

After just over a day it did a resync and back to 3dB again, couple of hours later, because the SNR had dropped below 2dB, it resynced again this time 9dB SNR.

Since then I have tried several resyncs, hours and/or days apart but no success - still 9dB. Ping up from 12ms to 28ms.

So I wish you luck and hope you are able to get it sorted

 

robski1
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Registered: ‎06-11-2008

Re: SNR has suddenly increased and speed dropped

Thanks Stumpy21.

I'll let you know if things improve. Do you still get random resyncs?

Stumpy21
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Registered: ‎13-06-2011

Re: SNR has suddenly increased and speed dropped

The only automatic/random resyncs I get are usually caused by the SNR dropping to a level (<2dB) that the connection is unable to hold on to. As I have a 9.4dB SNR at the moment I would expect it to stay connected for months!

Have you signed in to the TG582N and checked the log to see if that gives you any clues?

robski1
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Registered: ‎06-11-2008

Re: SNR has suddenly increased and speed dropped

Thanks for the suggestion, I will have a look in the morning and see if it tells me anything.

I am at 9.1 SNR at the moment, I will see what happens overnight.

Community Veteran
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Registered: ‎31-08-2007

Re: SNR has suddenly increased and speed dropped

Hello guys/gals. Firstly, the staff that support theses boards don't work w/ends.
2nd, if DLM has raised the Target SNRM, it's not because it's got it's knickers in a twist, it's because it's found a problem with your connection and is trying to stabilise things.

@robski1 it sounds like your line is now picking up some interference which it didn't before or has become noisy for some other reason, there could be a line fault - which might be intermittent which won't help. But the fact that this appeared initially to start late at night when general background interference levels are higher means any additional noise will reduce any margin you had, never mind the errors that will come with it. Raising the Target SNRM is a way of putting back some of the margin.

Are you still getting drops in connection - especially daytime ones, with the 9dB Target?

As you are running a TG582n, it has an extremely good/useful Event Log and for that very reason I don't recommend using DSLStats as it fills the log (limited size) with entries every time it samples and you will lose other potentially useful data. I would go for RouterStats, in the first instance RouterStatsLite as it's quick and easy to set up. If you want to give this a try, I'll give you some setup tips.

Posting the full xDSL stats from the 582n would probably be useful, but also look at the Event log - from the LH menu below >Home select >Technicolor Gateway then select >Event Log. Now the GUI version is not very big so have a look at it as soon as you can if you notice a drop in connection. You need to telnet to get a bigger log - are you familiar with Telnet? Again I can give you some guidance if you need it. You can do a copy/paste of the Event log - it doesn't matter about the graphics. (PS. the "errors" you may see aren't errors in the traditional sense!).

robski1
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Posts: 132
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Registered: ‎06-11-2008

Re: SNR has suddenly increased and speed dropped

Hi Anotherone

Thank for your reply, there were no disconnects last night so I have cleared the event log and will do as you suggest and have a look at them as soon as I see another disconnection.

Here are Stats since the last disconnect:

Uptime: 0 days, 18:23:29
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1,234 / 11,458
Data Transferred (Sent/Received) [MB/GB]: 123.42 / 1.26
Output Power (Up/Down) [dBm]: 12.8 / 0.0
Line Attenuation (Up/Down) [dB]: 12.5 / 25.0
SN Margin (Up/Down) [dB]: 5.9 / 9.0
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN
Loss of Framing (Local/Remote): 54 / 0
Loss of Signal (Local/Remote): 6 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): -
Error Seconds (Local/Remote): 120 / 4
FEC Errors (Up/Down): 423 / 14,714
CRC Errors (Up/Down): 39 / 342
HEC Errors (Up/Down): 21 / 32,741

 

The download sync used to be in the high 15's.

I will see how it goes over the next couple of days and the try RouterStats if necessary.

I am not familiar with Telnet so I may have to come back to you for help on that one too.

Thanks again,

Rob.

 

 

robski1
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Registered: ‎06-11-2008

Re: SNR has suddenly increased and speed dropped

I have just had another disconnect.

Here is the event log from the router:-

 

Aug 15 09:05:54 LOGIN User admin logged in on [HTTP]
Info  Aug 15 08:59:33 CONFIGURATION saved by TR69
Warning  Aug 15 08:58:43 PPP link up (Internet) [87.112.43.124]
Info  Aug 15 08:58:43 FIREWALL event (1 of 1): modified rules
Info  Aug 15 08:58:43 FIREWALL event (1 of 1): created rules
Info  Aug 15 08:58:43 FIREWALL event (1 of 2): deleted rules
Info  Aug 15 08:58:43 PPP CHAP Receive success (Internet)
Info  Aug 15 08:58:42 PPP CHAP Receive challenge from rhost PCL-AG02 (Internet)
Info  Aug 15 08:58:42 PPP CHAP Receive challenge from rhost bras-red5.dy (Internet)
Info  Aug 15 08:58:39 xDSL linestate up (ITU-T G.992.5; downstream: 11445 kbit/s, upstream: 1236 kbit/s; output Power Down: 20.8 dBm, Up: 12.7 dBm; line Attenuation Down: 25.0 dB, Up: 12.6 dB; snr Margin Down: 9.3 dB, Up: 6.4 dB)
Warning  Aug 15 08:58:13 PPP link down (Internet) [146.90.96.120]
Info  Aug 15 08:58:12 xDSL linestate down
Info  Aug 15 08:57:42 xDSL linestate down
Info  Aug 15 08:57:25 FIREWALL event (1 of 1): modified rules
Info  Aug 15 08:57:25 FIREWALL event (1 of 1): created rules
Info  Aug 15 08:57:25 xDSL linestate down
Info  Aug 15 08:16:42 SNTP Synchronised to server: 212.159.13.49
Error  Aug 15 08:09:51 FIREWALL icmp check (1 of 1): Protocol: ICMP Src ip: 50.97.52.114 Dst ip: 146.90.96.120 Type: Destination Unreachable Code: Port Unreacheable
Info  Aug 15 07:16:42 SNTP Synchronised to server: 212.159.13.50
Info  Aug 15 06:50:46 LOGIN User admin logged in on [HTTP]
Info  Aug 15 06:34:33 LOGIN User admin logged in on [HTTP]
Info  Aug 15 06:16:42 SNTP Synchronised to server: 212.159.13.49
Info  Aug 15 06:12:01 LOGIN User admin logged in on [HTTP]
Info  Aug 15 05:16:42 SNTP Synchronised to server: 212.159.13.50
Info  Aug 15 04:16:42 SNTP Synchronised to server: 212.159.6.10
Info  Aug 15 03:16:42 SNTP Synchronised to server: 212.159.13.49
Info  Aug 15 02:16:41 SNTP Synchronised again to server: 212.159.13.50
Info  Aug 15 01:16:41 SNTP Synchronised to server: 212.159.13.50
Info  Aug 15 00:16:41 SNTP Synchronised to server: 212.159.13.49
Error  Aug 14 23:40:14 FIREWALL icmp check (1 of 1): Protocol: ICMP Src ip: 144.232.7.126 Dst ip: 146.90.96.120 Type: Time Exceeded Code: Time to Live exceeded in Transit
Error  Aug 14 23:25:42 FIREWALL icmp check (1 of 1): Protocol: ICMP Src ip: 198.143.188.134 Dst ip: 146.90.96.120 Type: Echo Reply Code: 0
Info  Aug 14 23:16:41 SNTP Synchronised again to server: 212.159.13.50
Info  Aug 14 22:54:19 LOGIN User admin logged in on [HTTP]
Info  Aug 14 22:24:52 LOGIN User admin logged in on [HTTP]
Info  Aug 14 22:16:41 SNTP Synchronised to server: 212.159.13.50
Info  Aug 14 21:25:49 LOGIN User admin logged in on [HTTP]
Info  Aug 14 21:16:41 SNTP Synchronised again to server: 212.159.13.49

 

Does give any clues as to what is happening?


 
   
hitchhiker43
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Registered: ‎06-07-2016

Re: SNR has suddenly increased and speed dropped

All I ever get in my router log is hackers trying to break my firewall, day in day out, all day and night!

Tp-link W8960n on longgggggggg line!
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Registered: ‎31-08-2007

Re: SNR has suddenly increased and speed dropped

@robski1 well done for the stats and catching the event log at a good time.
The stats confirm your 9dB DS Target SNRM and that you'd (at the time) previously had 6 drops since the last power on. Whilst the underlying CRC errors aren't too bad, your line is not performing very well for its length (attenuation) and perhaps ought to do a touch better even with a 6dB target.

Users always think that nothing in the house has changed that could affect things, but that's not always an accurate assumption. Electronic/electrical equipment can develop faults which may start generating interference even without any other outwardly noticeable symptoms. Not that there is any evidence of that at this time, but it mustn't be ruled out yet. The log just show that the DSL connection dropped.
What is interesting is the timing - now this could be pure speculation, but it may some activity associated with "working hours" - some device/equipment somewhere local perhaps creating a spike and causing the connection to drop. Are you able to relate any previous drops to possible activity in the home or locally? Is there any work going on at your exchange or cabinet - upgrading for FTTC perhaps or is that already available?

The current stats since the last drop may help fill the picture a bit more. I'll post back later with a few things worth checking through.

Community Veteran
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Registered: ‎26-09-2015

Re: SNR has suddenly increased and speed dropped

The router has now started to reboot it's self during the day as well as at night.

Do you actually mean "reboot" or do you mean the DSL disconnects and reconnects?