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Excellent fast connection and wireless, request to change target SNR ?

Rickkk
Dabbler
Posts: 10
Registered: 02-12-2014

Excellent fast connection and wireless, request to change target SNR ?

Hello. I have a very good set up which includes...
Asus DSL-N66U acting as the Plusnet ADSL2+ modem and router (connected directly into Openreach faceplate at the master socket), and to extend wireless around the home a Asus RT-N66U set up as a 'wireless extender'. This gives flawless results with full wireless signal all over.
Before moving to Plusnet, I was with Sky Broadband, and I had a steady 20Mbps connection with a SNR of 3db.
Now I obviously have a target SNR of 6, which is taking off ~4Mbps.
The Asus DSL-N66U is obviously ready for the easy change over to VDSL2+, but for now until I upgrade my package, is there any chance you could fix the target SNR to 3db to increase my connection speed?
16 REPLIES
Plusnet Help Team
Plusnet Help Team
Posts: 12,859
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Registered: 27-04-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

Hi Rickkk,
It's not guaranteed to work but we're happy to give this a try for you.
I've submitted an SNR reset specifying the downstream at 3dB so you should hopefully start to see some difference over the next 24 hours.
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
Rickkk
Dabbler
Posts: 10
Registered: 02-12-2014

Re: Excellent fast connection and wireless, request to change target SNR ?

Thanks, nothing changed yet.. did that reset go through ok?
Superuser
Superuser
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Registered: 22-08-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

Something is not entirely right here!  Something has changed though.
The DS SNRM has gone up, but so has the synch rate, which is not what one would expect.  Can you monitor the SNRM - this is not a fixed metric, it will vary in response to line noise.  Is the phone line quiet?  Dial 17070 option 2.  Do it regularly to see if you have intermittent noise.
Given the latest SNRM I suspect the target is 9dB or you have had a modicum of noise on the line.  The current line speeds are right on the nail for a reported attenuation of 30dB.
Edit: Do you recall what was the reported line attenuation when you were with Sky?  Remember they use different technology in the exchange compared to BTOR and a direct comparison might not be appropriate.
Plusnet Staff
Plusnet Staff
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Registered: 05-04-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

The SNR reset failed yesterday. I'd suggest against a fixed SNR of 3db as that could cause intermittent connection issues, I'm happy to reset this to a target of 3db and allow DLM to make changes where required. It's also worth noting that a 3db decrease in SNR will generally give just less than 1Mb increase in speed.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
Plusnet Staff
Plusnet Staff
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Registered: 05-04-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

Looks like the reset has been successful this time. Let us know how it goes and keep an eye on your connection for issues.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
Rickkk
Dabbler
Posts: 10
Registered: 02-12-2014

Re: Excellent fast connection and wireless, request to change target SNR ?

Thanks Chris, looks much better now  Smiley
As for the SNR before, the first one (6.8dB) was in the middle of the night when noise is at its highest, the second (8.9dB) was at mid day.
I'll see how it goes  Smiley
Rickkk
Dabbler
Posts: 10
Registered: 02-12-2014

Re: Excellent fast connection and wireless, request to change target SNR ?

Having said that, download speed is still around 14Mbps and on the Plusnet page it shows Current Line Speed as 13.6Mbps ?

Is there anything else that needs to be reset or will this update itself in good time? Thanks.
Plusnet Staff
Plusnet Staff
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Registered: 05-04-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

It will update in the next few hours, but I'll go do it manually now. Give me a couple of minutes, then log in to your router and do a disconnect/reconnect.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
Superuser
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Registered: 22-08-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

Quote from: Rickkk
As for the SNR before, the first one (6.8dB) was in the middle of the night when noise is at its highest, the second (8.9dB) was at mid day.

Ouch!  A 2.9dB swing between day and night could mean that at night time, you will get "blown out" with only a 3dB target and the DLM might quickly set you back to 6dB.
You advised that the router is plugged into the master socket.  Are there any extension sockets?  If yes, what kind of wiring do the have (number of wires and colours).  Is there a wire connected to terminal 3 on the back of the faceplate(s).  What kind of master socket have you got?
I am wondering if you might have issues with internal wiring which is amplifying the night time AM/MW interference.  I usually see less than 1dB day / night variation and therefore live very happily on a 3dB SNRM even on a 50dB attenuated line.
Rickkk
Dabbler
Posts: 10
Registered: 02-12-2014

Re: Excellent fast connection and wireless, request to change target SNR ?

Internal wiring is very old, but its all recently been disconnected and the modem and phone have been moved next to the master socket. Phone line is crystal clear.
All the premises in the block had new copper wires installed to the pole, and the master socket has an Openreach Mk2 faceplate on ready for VDSL.
To be honest ive never noticed that much SNR difference between night and day, but obviously I don't always check it. Very few disconnections other than ones done by me anyway (usually reconfiguring router).
Thanks for your reply  Smiley
Rickkk
Dabbler
Posts: 10
Registered: 02-12-2014

Re: Excellent fast connection and wireless, request to change target SNR ?

Thank you Chris, you're a star  Smiley



If DLM changes me back to 6dB then so be it, hopefully not though I can't think why it would  Huh
When your VDSL is less then ~£36 a month, i'll be upgrading anyway, but for now this connection is perfect  Cool
Superuser
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Registered: 22-08-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

I suggest that you keep a regular watch / record of your SNRM for a couple of days.  If the variations look untoward, then may be we might look at 24x7 monitoring / logging with something like router stats to see if there are any patterns to be concerned about.
At the time of a resynch, that will be done at a speed which delivers the TARGET SNRM.  Thereafter if noise increases, the SNRM will fall, if it decreases it will rise.  Therefore if the target is 3dB and you...
Resynch at night whilst AM/MW noise is present, the synch speed will be slower and during the day you will see an elevated SNRM reported
Resynch during the day (no AM/MW noise) you will attain the best synch speed and during the night you will see a reduced reported SNRM - if this falls too low, you will at best see high error rates with slow performance, at worse you will have a disconnection, but then the above will become effective.
If the latter happens too often, the DLM will move the target to 6dB again.
The cause of the interference could be something completely different to night time AM/MW radio transmissions - detailed stats plotting usually makes this possibility plain... if you want to put the effort in!
EDIT: Those tone plots you posted whilst I was typing look interesting - there are regular gaps in the spectrum.  I'll point Anotherone here and see if he has any thoughts on this, as it looks to me like there might be harmonic interference here... but he knows far more about this stuff than do I.
Community Veteran
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Registered: 31-08-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

Hi there Rickkk, welcome to the Forum by the way.
At a quick glance, I was surprised you were getting a 20Mbps connection with Sky on a 3dB Target SNRM on a 30dB line. You were obviously lucky, maybe the dedicated DSL processor in your Asus means it can bit swap very effectively. Anyway all supposition.
With regard to Townman's comment regarding the tone gaps - I think his memory is fading a bit Wink
Whilst the clarity of the scale on the graphs is abysmal, I can see that with the exception of the gap immediately above tone 64 (looks like it's around tone 70) all the other gaps are standard gaps at particular tones seen frequently with a number of 21CN MSANs and certain modem chipsets - there are 7 such gaps, so nothing to worry about. But as I've said I have no idea what the gap around tone 70 is.
Superuser
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Registered: 22-08-2007

Re: Excellent fast connection and wireless, request to change target SNR ?

If I never knew, then my memory could not have faded!  Cheesy
As I said, you know lots more about this space the do I.  In all the tone plots I've looked at, I have not discerned such regular gaps before, which I now know to be a function of the combination of router and exchange chipsets!  Learnt something new today, so thank you for the illumination!  Grin