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[kezzaman]

Hello fellow gamers.

 
I have discovered that by having a higher than normal SNR (normal being the level that the DLM has chosen for you) you will receive a much better gaming connection.

 
In a BT exchange there is a machine called the DSLAM, this is where the line that runs from your house goes to and within the DSLAM is a system called DLM (Dynamic Line Management system)

 
These machines will automatically chose an SNR level that best suits your line so that you receive the fastest possible speed.

 
BUT, dont think that by having the fastest possible speed that you will gain the best possible gaming connection!!

 
By raising the SNR level 3 or even 6 db will slow down you speed half a MB or so but will seriously improve your gaming connection.

 
SNR means noise margin and you can check what yours is from your routers settings, look here if your need help http://www.kitz.co.uk/adsl/frogstats.php .

... And another thing dont be fooled by the fibre optic commericals, you dont need those super fast speeds for gaming. 2MB is plenty, just as long as your not doing anything else on the net at the same time.

 
I hope this helps you gamers out there. I know how frustrating it can be!

 
Peace.

 
P.S. theres just 1 problem     actually getting Virgin, BT or who ever to change the snr settings for you can be quite difficult.     GOOD LUCK!



[qpop]

Depending on your modem you can tweak the SNR, either through telnet (some Broadcom chips like my old Zoom ADSL 2/2, or a Netgear DG834GT, for example), or through the GUI (Billion 7800N or a custom firmware model of Netgear DG834GT)

[kezzaman]

Depending on your modem you can tweak the SNR, either through telnet (some Broadcom chips like my old Zoom ADSL 2/2, or a Netgear DG834GT, for example), or through the GUI (Billion 7800N or a custom firmware model of Netgear DG834GT)

Yea i know but that only lasts for a few hours and the DLM (im guessing the DLM) just returns it back to the way it was and then you cant tweak it at all for a couple of days.

   

[jeffbb]

Hi
Your SNR margin is normally optimised at 6db .Using that +your attenuation determines basically determines your synch rate ,also taken into account is the amount of noise on the line .If your line has been unstable then you may infact connect with a High SNR margin 9,12,15db this is NOT good news.
The Important thing for Gamers is Latency the lower the better .High latency is associated with noisy/unstable  lines ,the latency is caused by the level of Interleaving.So  if you have a low SNR margin but high latency then  increasing your SNR margin and getting latency down will improve your gaming connection.
Tweaks will stay as long as you do not resynch. You can using the DMT tool save the setting so it works even after a resynch.
Regards Jeff

[kezzaman]

When i raise my snr the latency stays the same but my gaming connection improves. I've used the DMT tool it only lasts for a few hours and then just returns to its original level.

[jeffbb]

Hi
Have you saved the tweak ?
Regards Jeff

[sevenlayermuddle]

Well, here's my theory...

SNR margin is a trade-off against the frequency of transmission (CRC) errors.  Such errors are corrected by higher protocol layers (TCP), but it means the data needs to be retransmitted, which can cause a significant 'pause' in the data stream.  I'm not a gamer, but I should imagine any such pauses would be unwelcome.

Raising the SNR margin should reduce the frequency of CRC errors, hence I would be prepared to accept it is of benefit to gamers.

For similar reasons (reduction of CRC errors) I believe true IPTV (that is TV over IP, without TCP - hence no error recovery)  services often mandate a higher SNR Margin.

- 7LM

[kezzaman]

@ Jeffb,  no i didnt see any save button i just altered the snr and then hit apply/resync.

[kezzaman]

Well, here's my theory...

SNR margin is a trade-off against the frequency of transmission (CRC) errors.  Such errors are corrected by higher protocol layers (TCP), but it means the data needs to be retransmitted, which can cause a significant 'pause' in the data stream.  I'm not a gamer, but I should imagine any such pauses would be unwelcome.

Raising the SNR margin should reduce the frequency of CRC errors, hence I would be prepared to accept it is of benefit to gamers.

For similar reasons (reduction of CRC errors) I believe true IPTV (that is TV over IP, without TCP - hence no error recovery)  services often mandate a higher SNR Margin.

- 7LM

Hi 7LM,

I really like your theory and i was wondering maybe you know of some alternate methods of reducing CRC errors? They might be helpful.

Thx

[jeffbb]

I don't use the DMT tool but I thought that there is an option to save .Any DMT users ??
regards Jeff
edit

enabling the Hidden 5th Tab to change your Target SNR
•From the top toolbar select ◦Special
◦Misc. Options

•A new window will open Misc. Options/Settings
•From Expert Settings -
•Tick the checkbox "unlock experimental area Panel/Last Tab
•Click the "Save/Close" Button

The slider allows you to adjust your SNR with 100% being your existing the BT set figure.

The slider is not entirely accurate, and because each line is different then you will have to experiment
see more at
http://www.kitz.co.uk/routers/DMTv8.htm
 

[kezzaman]

Hey Jeff yea i did that, u save the snr slider in the 5th tab and then all u do is set it to what you want and hit apply/resync.

[sevenlayermuddle]

Kezzaman,

I trust you are aware that the SNR will always vary following the initial connection - that is completely normal.   It willoften follow a 24 hour cycle,  dropping to a 'low' in the hours of darkness, and rising to a 'high' in the daylight hours.

For example, if you connect at 7am with a margin of 9dB, you may find that by 1pm is has risen to 10dB, yet by 3am next day is has dropped to 7dB.  These figures are only examples, of course.

Conversely, if you connect at 1pm with a margin of 9dB, you find it drops to a low of (say) 5dB overnight, before recovering to 9dB again.

The way to turn that to your advantage, if you are in pursuit of a generous SNR margin, is to force the router to reconnect in the hours of darkness, say around midnight.  You might then find the the SNR margin gets better as the day goes on, then drops back towards its initial value overnight, but rarely drops much below that initial value.

- 7LM

[KHell]

The OP is spot on about this in his first post.

I'd just like to add that Noise Margin is a resultant figure calculated from several factors:
Length of wire from Exchange; Speed applied to length of wire; Quality of wire.
The noise margin can be calculated from these values & nothing more. Cross-Talk can also deplete Noise Margin & that is very difficult to calculate. Also, your Noise Margin should only ever fluctuate by 1db, 2db @ worst. Mines doing 15db in the day & 3db in the evenings atm.
You hear ISP's talking about Target SNR which is just as bs as them talking about Interleaving. Interleaving is something thought up by BT to help customers with poor quality phone lines stay connected, instead of doing the right thing & replacing the crap copper Network they have screwed us all over for the last 10 years. Having loaded the Copper beyond comprehension, they install Fibre without releasing the bottlenecks they have caused on Copper & then still expect you to pay for a fibre experience that relies on heavily overloaded D-side copper in order to get to the Fibre Cabinet. Reduced Noise Margins on ADSL will mean Reduced signal to get to the Fibre cabinet, yet Corporate dickwads alegedly working for BT Wholsale can not see this.

I know I can get 23db Noise Margin downstream on my wires with an 8192 Speed applied. However, it now sits @ 15db for the last weeek since complaining to my ISP 3 weeks ago for only seeing 6/7db with a 5022 speed applied. For the last 7 months, it was hanging @ 12db & my noise margin just get totally annihilated by the evening. Last night I was down to 3db leaving me almost dead in the water & this morning it only recovered to 11db @ best. Re-setting the Router gave me 15db....

See my very long & still on going issues here:

http://forum.kitz.co.uk/index.php/topic,9900.0.html

Unless you can have ALL the Noise Margin your wires are capable of delivering, your Gaming will be useless & Surfing will be clunky. It's looking like my ISP might the root cause of my bad experiences atm, but I am also convinced BT are involved in this as well. One blames the other & nothing is done to resolve customers issues, but both parties still take your money for services that do not perform as they should. Ofcom & such are set up to protect customers & their mandates are just as pathetic as your ISP & BT corporately shafting you in any manner they can. I guess it depends how much one wants to bleed.
 

[kezzaman]

I was wrong about this! 

Sorry.