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How to reduce my SN Margin margin and maximise my IP profile

Thomastank
Dabbler
Posts: 17
Registered: 08-10-2008

How to reduce my SN Margin margin and maximise my IP profile

I have until recently been running  my router of a hardwired telephone extension and decided to try and improve my line by moving my router to the main telephone master socket and connecting directly to the computer by Ethernet cable cutting out all extension wiring and plugging into the main master telephone point.
My Bandwidth  is (Up/Down) [kbps/kbps]: 448 / 7,616
My IP profile is 6500 while I know this is very good but I feel with the line Attenuation (Up/Down) [dB]: 16.0 / 26.0 it could be improved upon.
The SN Margin is (Up/Down) [dB]: 22.0 / 15.0 !!!  I think the target noise margin is set to 15 as it goes to this when the router is rebooted and fluctuates between 14 and 16
I feel if I could reduce the noise margin and with the improvements in the  telephone line set up !! my Ip profile would improve slightly.
I would prefer not to try to adjust the noise margin manually by the DMT tool which I believe you can use on the thomson router as to be honest I am not that technically adapt.
I will post my router stats below and if any one has any ideas in what i could do to improve things  .I do wonder if the target noise margin has been set at 15 from when i had the hard wired extension !!
While I know many people would be more pleased with the IP Profile that I have I have paid to get the Ethernet cable done and hopefully would like to see an improvement on the IP Profile
Many thanks for any replies
Thomson TG585 v7

Uptime: 0 days, 0:35:28
DSL Type: G.992.1 annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 7,616
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 0.00
Output Power (Up/Down) [dBm]: 11.5 / 19.5
Line Attenuation (Up/Down) [dB]: 16.0 / 26.0
SN Margin (Up/Down) [dB]: 22.0 / 15.0
Vendor ID (Local/Remote): TMMB / ALCB
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 0 / 0
FEC Errors (Up/Down): 0 / 61
CRC Errors (Up/Down): 0 / 2
HEC Errors (Up/Down): 0 / 2

7 REPLIES
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: How to reduce my SN Margin margin and maximise my IP profile

We could turn off interleaving, which may result in an improvement in sync speed.
It's worth pointing out that you probably won't see any improvement in throughput speed bar 100-200Kbps if you're lucky.
Thomastank
Dabbler
Posts: 17
Registered: 08-10-2008

Re: How to reduce my SN Margin margin and maximise my IP profile

Thank you James for your quick reply  !!
For the line Attenuation I thought i could receive a IP profile of 7150 !! would this increase make any real difference to my speeds and what would your advice be !! Is it best to leave it alone and be satisfied with an IP Profile of 6500 or would turning interleaving off be beneficial in reducing the snr margin and in turn probably increase my IP profile !! What would you suggest if you were in my position
paulby
Grafter
Posts: 1,619
Registered: 26-07-2007

Re: How to reduce my SN Margin margin and maximise my IP profile

7616 is tha maximum you can sync at with interleaving turned on and 6500 is the profile that BT will assign.
Turning interleaving off will give you a sync of 8128 and will likely result in a profile of 7150.
Your SN margin is already excellent (6dB is the lowest you can go without problems - if you're syncing at 6716 or 8128 without interleaving then a higher number is good as it shows you've more signal and less noise!). Removing interleaving won't reduce your SNR but it will allow you to sync at 8128 (the maximum possible).
I'd ask to have interleaving removed - you can do that here.
Have a look here for a description of interleaving.  As you're quite close to the exchange (from your stats) and have a good high SNR margin you should be able to turn off interleaving without any problems.
Also have a look at this post and the one following it by Barry Zubel for an expalnation of SNR margin.
Thomastank
Dabbler
Posts: 17
Registered: 08-10-2008

Re: How to reduce my SN Margin margin and maximise my IP profile

Many thanks Paul for your reply !
If you could confirm that I have got this right in that the maximum rate with interleave on will be 7616 kbps(as my router stats show) and no matter how low my noise levels are it will not improve at all .( my line profile is 6500)
To achieve the full rate 8128kbps and improve my profile  the only way to do this is to remove interleaving of my line I also understand that by turning interleave off it could effect the stability of my line
What confused me was that I understood that noise margin is set at 6db by BT and will increase by 3db each time if you have a unstable connection and in turn reduced your sync speed( hence I have improved the line quality by fitting an Ethernet cable directly to the computer and moving the router to the master telephone socket) but I did warn you that I am not very technically adapt
Thanks Thomas
paulby
Grafter
Posts: 1,619
Registered: 26-07-2007

Re: How to reduce my SN Margin margin and maximise my IP profile

That's correct.
Maximum rate with interleave on is 7616.  You can get 8128 with it turned off.
Because you've got a very good line turning interleaving off shouldn't cause any instability problems - you can get it turned back on again if it does.
Hopefully the posts I linked to explained how SNR etc. works.  You've synced at the maximum rate at a high SNR margin as you have a good line with very little noise (SNR = Signal to Noise Ratio, i.e you've a lot more signal tha n noise).
Community Veteran
Posts: 1,571
Thanks: 3
Registered: 13-04-2007

Re: How to reduce my SN Margin margin and maximise my IP profile

Have you got any phone extensions if so removing the bell wire may improve things or failing that a Iplate if you dont feel happy  removing the bell wire
paulby
Grafter
Posts: 1,619
Registered: 26-07-2007

Re: How to reduce my SN Margin margin and maximise my IP profile

@Samurai
He doesn't need to do anything!  His line is already syncing at the maximum rate possible for Max DSL. 
Removing the ring wire won't make any difference in this case as the line has a very good SNR as it is (22dB).  Turning interleaving off will allow the full 8128 to be achieved (7616 is the maximum achievable with interleaving turned on).
The high SNR means that there's more headroom on the line for faster speeds when ADSL2+ comes along.  With his stats the OP should be looking at 20meg+.