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Sinking Sync Rate!

MrT
Grafter
Posts: 379
Registered: 30-06-2010

Sinking Sync Rate!

Since the end of May, my line seems to have become ‘unstable’ and has been resyncing pretty much every day with the odd exception. Sync Rates have varied between 3904 and 3008.
The rate has dropped below 3424 on 3 occasions with the resultant drop in my IP Profile to 2500.  Cry
During the whole of this time my line attenuation has been constant at 56dB and the SNR Margin has varied between 4dB and 6.5dB.
I am uncertain as to what my best course of action might be and would welcome any advice on this.  Undecided
I don’t have one of those fancy master sockets (i.e. one with a test socket).
I have 2 telephones – 1 in the master socket and the other in an extension socket.
The router (14 months old PN supplied Thomson TG585v7) is plugged into the extension socket.
I have done a quiet line test – there is a continuous very low level of noise on the line.
I have tried removing both phones.
I have changed both ADSL filters.
The only other options I can think of involve spending money (which I don’t mind provided the desired result is achieved).
I could ask BT to fit a new master socket – I’ve read somewhere they would charge £170 (+VAT?).
I could buy a new router – perhaps a Billion 7700N (£50) or an Edimax AR-7284WnA (£21).
I’m tempted to buy a new router and see if that fixes the problem. Beyond that I have really no idea what I should do.
Router Stats just after restart and a Noise Margin graph from RouterStats are attached.
All ideas welcome.
23 REPLIES
lexusuk
Grafter
Posts: 567
Registered: 20-10-2009

Re: Sinking Sync Rate!

Hi MrT,
I'd suggest that you obtain the same line stats but from the master socket directly before spending any money.  That way we can make a direct comparison to see if your internal wiring is causing any issues.
MrT
Grafter
Posts: 379
Registered: 30-06-2010

Re: Sinking Sync Rate!

Hi Alex,
When I test from the master socket, should I disconnect both telephones? This would leave the extension open circuit (unless I leave the ADSL filter in the extension socket) - I'm not sure what effect that might have ; it may make a very good aerial!
lexusuk
Grafter
Posts: 567
Registered: 20-10-2009

Re: Sinking Sync Rate!

Leaving the extension circuit shouldn't cause any issues.  However, it would be worth obtaining stats with phones connected and phones disconnected if you want to be thorough.
MrT
Grafter
Posts: 379
Registered: 30-06-2010

Re: Sinking Sync Rate!

Thanks Alex. I'll record line stats tomorrow with and without telephones connected.
Stumpy21
Rising Star
Posts: 156
Thanks: 6
Fixes: 1
Registered: 13-06-2011

Re: Sinking Sync Rate!

Quote from: MrT

I don’t have one of those fancy master sockets (i.e. one with a test socket).


I take it that you have already checked and disconnected the ring wire, as here http://www.kitz.co.uk/adsl/socket.htm
Derek
MrT
Grafter
Posts: 379
Registered: 30-06-2010

Re: Sinking Sync Rate!

Hi Stumpy21,
Thanks for the thought. Yep, I disconnected the ring wire last November and got an increase in sync rate from 2080 to 3744. The uptime at that rate was 61 days  Cheesy
Since then the best I've achieved is 27 days. I'm currently lucky if I get 3.
I just wonder whether this very dry summer we're having in the Midlands is, at least partly, to blaim for my routers' declining stability.
Stumpy21
Rising Star
Posts: 156
Thanks: 6
Fixes: 1
Registered: 13-06-2011

Re: Sinking Sync Rate!

Quote from: MrT

I just wonder whether this very dry summer we're having in the Midlands is, at least partly, to blaim for my routers' declining stability.

I have heard that routers can suffer from overheating! People have recommended raising or angling them higher off the table etc. if horizontally mounted.
You will need the knowledge of someone better than me, but I understand it can be good practice to restart the router regularly, to clear out any noise generated bit swaps
and get your original sync rate back!  Undecided
Derek
MrT
Grafter
Posts: 379
Registered: 30-06-2010

Re: Sinking Sync Rate!

Quote from: Stumpy21

I have heard that routers can suffer from overheating! People have recommended raising or angling them higher off the table etc. if horizontally mounted.

I've tried the router both horizontal and vertical over the past 6 months. No discernible difference in stability.
Quote from: Stumpy21

You will need the knowledge of someone better than me, but I understand it can be good practice to restart the router regularly, to clear out any noise generated bit swaps
and get your original sync rate back!  Undecided

An interesting suggestion. Perhaps an expert might comment on this.
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Sinking Sync Rate!

There's no harm in rebooting the router once a day at quiet times (like first thing in the morning or before you go to bed.
I'd avoid doing it more regularly than that.
MrT
Grafter
Posts: 379
Registered: 30-06-2010

Re: Sinking Sync Rate!

So tomorrow, when I move my router to the master socket and record stats with and without phones plugged in are you saying that I should not reboot at each change of telephone? I was thinking of using the GUI to disconnect PPP, then restart the router, then connect PPP.
My current profile is 2500 so hopefully I would not go below that.
dick:quote
Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: Sinking Sync Rate!

Quote from: Jameseh
There's no harm in rebooting the router once a day at quiet times (like first thing in the morning or before you go to bed.
I'd avoid doing it more regularly than that.
and that will pretty well guarantee a low sync speed and may solve the problem but then again you wouldn't necessarily appreciate a lowered IPprofile either
Superuser
Superuser
Posts: 9,465
Thanks: 814
Fixes: 52
Registered: 06-04-2007

Re: Sinking Sync Rate!

Quote from: MrT
So tomorrow, when I move my router to the master socket and record stats with and without phones plugged in are you saying that I should not reboot at each change of telephone? I was thinking of using the GUI to disconnect PPP, then restart the router, then connect PPP.

Once you've moved the router I wouldn't re-sync again when plugging in and disconnecting telephones (and the unused filter in the extension socket). I wouldn't even disconnect from Plusnet. Changes in noise margin are what should be looked for. Significant changes there would (most likely) lead to sync speed changes if you did re-sync but checking noise margin gives a better feel for effects.
Try to plug in and remove phones cleanly to minimise risk of noise spikes causing a re-sync.
David
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Sinking Sync Rate!

Sorry - I should have said that my suggestion would be likely to give you the best possible speed, but there's a decent chance of a drop during the day.
As spraxyt has suggested, there wouldn't be any value in resyncing again after moving the router on that day.
Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: Sinking Sync Rate!

To clarify.
This is my noise margin over the last 24 hours
You can see that the noise margin reduces during the hours of darkness.
A resync during that time will give a lower sync speed but may allow the router to hold sync as the noise margin will trend to increase from the low point. It may drop a bit further due to the vagaries of the bit swapping algorithm.
If however you resync during the day this will give the highest sync speed but the noise margin which was set at the default value will reduce as night draws on and may cause a resync.
In the first scenario you may get a lower IPprofile but with a better chance of holding sync over the 24 hours.
You can only try it and see.