Neighbour gets 2x bandwidth

[#1]

So, I've been with Plusnet for a few years now and enjoyed a reliable service.  Living out in the country some 3 miles from the exchange, never really expected to get a high bandwidth.  But fairly recently I was a bit shocked when I found out my neighbour just a few houses down was getting twice the download speed!
Here are his download stats:
Attenuation: 49.0 dB
SNR: 14.5 dB
Bandwidth: 3,808 kbps
and here are mine:
Attenuation: 52.5 dB
SNR: 16.5 db
Bandwidth: 1,856 kbps
So clearly, I have worse attenuation, but slightly better signal to noise.  So how come he gets more than twice the download sync speed?  This is reflected with a similar data throughput as well.
Incidentally, I have my router (DrayTek Vigor 2800 series) plugged into the face plate and have eliminated the extensions (essentially the same stats after a reboot).
Is there something I need to do to get my sync speeds recalculated (by BT?) other than just reconnecting by a router reboot?
Regards,
Richard.

[#2]

With your attenuation, I'd have expected a much faster speed.  I mean, my own attenuation is over 63.5dB and I still get a speed of around 2mbit/s.
Your high SNR margin is a little worrying.  Is your connection prone to dropping?  It could be that the DLM has given you a either a 15dB target SNR margin, or that you've been possibly speed banded.  As I don't know whether you're on ADSL2, I can't answer that further.
It might be worth borrowing/stealing a different ADSL router from a friend... or asking Plusnet for their branded Speedtouch 585v7 one.  I know the Draytek is a good router, but I've seen lots of posts about how the ADSL side of it isn't 100% compatible with ADSL2.
Personally, I like the Netgear DG834Gv4, as it is very stable on long distance lines.  Can be picked up very cheap on e-bay.  I hear the 'GT version is good too.
-- gyre --

[#3]

Yes, I keep an 834GT on standby for fault checking. Ultra reliable. I don't use it all the time as I need 5ghz N to broadcast across the house.
I'd raise a ticket or ask the staff here to look at it.

[#4]

Quote from: swinfen

Living out in the country some 3 miles from the exchange, never really expected to get a high bandwidth.

I'm in a semi-rural position, 3 miles as crow flies, approx 6 miles of cable, apparently.  Also didn't expect wonderful speeds, but have seen reduction from 1.5 Mbps to 750 kbps and then 250 kbps or even 160 kbps sync speed, 128 kbps throughput, and if it rained, nothing at all for a few days. 
I have the same downstream sync speed (since yesterday, when BT replaced the drop wire and fitted a new master socket, with some filtering built in [not an I-plate]) but as you can see, attenuation (if it can be believed) is a bit higher (and has in the past shown 59, 59.5, 60.5 db). 
noise margin ... downstream: 16 db ........  upstream: 22 db
attenuation ....... downstream: 57 db ........  upstream: 31 db
Speed: .......  Downstream 1856 kbps  ...  Upstream: 448 kbps
I'm using a Zyxel wireless router (bought on Ebay for under 6 quid inc delivery) because I noticed a better performance from another Zyxel Prestige router that I had on loan a few years ago, when living elsewhere and had first upgraded to 8 Mbps (but Conexant chipset was unable to cope with it for more than a few hours at a time),

Quote

So clearly, I have worse attenuation, but slightly better signal to noise.  So how come he gets more than twice the download sync speed?

Is the neighbour also connected via the BT equipment, or could he be on LLU kit from Sky / TalkTalk / other ?  Just in case his router / exchange hardware is working together more reliably...

Quote

Is there something I need to do to get my sync speeds recalculated (by BT?) other than just reconnecting by a router reboot?

Think you need to raise a ticket so PlusNet can get the exchange reset to have SNR back down at 6 db and just make sure you keep your router on and don't mess with it, so the exchange can see it is stable at 6 (or maybe 9 db).  As the SNR goes up the download speed will be cut more and more... but I am a little surprised neighbour SNR is also similarly high - wonder if there are electric fences or other types of interference affecting both lines (?)
I'm hoping to see higher throughput in a few days as it will take time for BT kit to accept my line is stable.  May leave it a couple of weeks and keep monitoring to see if it stays connected, and if so, I will ask PN to see if they can get the SNR reset back down to 6 db and then keep my fingers crossed that connection stays stable (and faster!)
Can only suggest trying different routers.  I do have the PN router, a SAR (non wireless), at least one other (AR41) and the Zyxel (perhaps another Zyxel in the garage).  If you can find a bargain s/h on Ebay it's always useful to have a spare and won't always break the bank, either, if you are patient...  Hope you see improvements in due course.

[#5]

Thanks for the feedback.  I don't believe I've been upgraded to ADSL2, but as you say the DrayTek is supposed to be compatible so if/when it happens, it should presumably take advantage - unless it's true it isn't great at ADSL2!  The exchange appears to be upgraded to 21CN at least.  I did actually buy a Sky DG934G router the other day, but screwed up the firmware upgrade - the software crashed and bricked it!  So might just go buy a 834 and try that.
The SNR does vary (now that I've been watching it a bit) seen it down at 12dB and as high as 18dB - syncing at 1.4Mb/s just now
Neighbour's ISP is O2, but other than that, should be the same - cable will only be a few hundred feet longer.  Was wondering if I could try to get BT to switch to a different cable in case that's the cause, but the router's stats would suggest it should be possible to attain higher sync rates.
So yeah, guess I'll raise a ticket and see what PN can do.  Had to raise one a few weeks ago as they had somehow capped my bandwidth at 340kbps for some reason.  They since have reset the cap to around 1.3Mbps - bit annoying they have to cap it.  They didn't respond when I queried why.  Clearly if I can get my sync speed up, I'll be pushing them to recalc my cap.
Any more comments welcome.

[#6]

So looking into this a bit more, isn't it the case that a higher SNR margin means lower noise level?  http://en.wikipedia.org/wiki/Noise_margin
Also http://www.kitz.co.uk/adsl/max_speed_calc.php suggests I should be able to attain an IP profile of ~3.5Mbps.

[#7]

O2 / Be Unlimited have their own kit so there is a chance your neighbour is connecting to completely different kit in the exchange (I know they can offer access via BT but the advantage in lower price and higher speeds/ traffic allowances are wiped out unless customer on their LLU kit, as far as I know).
The 340 kbps was probably the PN just doing a 'follow BT setting' as the exchange may have changed speed in response to you switching routers a few times, or having a load of disconnections in a short period...  Then, like some other instances, when the BT end increased again, PN didn't follow suit for some reason (seen a few comments in last day or two about this situation, don't know how common it is - lots of users will not know their transfer speeds so probably don't chase PN for increase).
As for the SNR - "higher the better" - well, the Wiki page seems a bit odd to me - just about every discussion I've seen (and will try to find FAQ which confirms) is that the exchange will compromise to increase the speed while maintaining a stable connection...  so if your connection remains stable at 6 to 9 db, while the Wiki article implies this is at the poor end of the range, it will give a stable connection with maximum speed (which is what most people are after).  If it is unstable, then pushing up the SNR should bring stability at cost of some speed.

[#8]

Kitz notes about ADSL2 says
"SNR /SNR Margin
The Signal to Noise Ratio on the max product is more flexible than on traditional adsl. On the older fixed line speed products an SNR Margin of less than 6dB suggested that there was a problem with the line.
With Max a target SNR margin is set on the DSLAM and its your router and the DSLAM that agree the best way of meeting this target margin. The target margin range is between 3dB and 15dB and rises in 3dB increments - although it is normal for it to fluctuate either side during the training period. The default is 6dB without interleaving."
Seems to me the Wiki article may still refer to situation for ADSL 1 with speeds of 500 kbps, etc (remember the bad old days? 🙂 )

[#9]

Is it just the case that he could be on ADSL2+ with O2?  Take it the effect would be 2x sync speed, if it is performing as specified?
Any way I can 'encourage' PN to upgrade me to ADSL2+?

[#10]

Might be best to see what PN staff response is tomorrow - I'm not going to speculate as to response but clearly you'd have an incentive to switch to O2 (even if it needed a PAYG and topup at a fiver a quarter, or whatever it costs) if you don't see any change on your PN connection.

[#11]

Agreed - worth giving them a chance, but I want my neighbour's speed - he doesn't even need it!
Looks like ADSL2+ might not prove much different at my attenuation level: http://www.adsl2forum.co.uk/showthread.php?t=6490

[#12]

Neighbour is not on ADSL2+.  Also don't think the exchange has any LLU equipment and in fact, appears ADSL2+ is not scheduled for the exchange at all.

[#13]

So - if I understand it correctly, the SNR Margin indicates the scope for additional bandwidth.  So if my IP Profile was increased Iby reducing my target SNR margin), my router's SNR margin would reduce, right?  With a high SNR margin right now, I'm inferring I have scope to do this.  Currently sitting at 20dB, which would indicate a fair scope for increasing the bandwidth!
Have raised with PN hopefully they can make conduct the change.
I see it is possible to fiddle with the target SNR with the Netgear DG834.  Bought one of those tonight to do so if I can't get any joy with the powers that be.

[#14]

Hi swinfen,
It appears that your profile has been lowered now to 1250, this is probably due to a number of disconnections since friday, so the fact that you've raised a speed fault is probably the best cause of action at this time. There's no reason why you should not expect speeds greater than you're experiencing, and if you could try another router then that may save you time in getting the fault solved. If you are not in a position to do that then we will have to see what the faults team find. We could always supply you with a router on a deferred contract so it would only cost you 4.99 for P&P to get one.
Jojo

[#15]

Quote from: swinfen

With a high SNR margin right now, I'm inferring I have scope to do this.

It is perhaps not quite as clear cut - given your neighbour has similar SNR there might be a reason for it (based on line length)...
However, looks like the course of action you've taken, going through PlusNet support with a ticket, will get this looked at for you.
Would suggest you try the Netgear router without messing with the SNR settings...