Downstream Margin versus SNR

i am sure this is simple but I have pput new LInksys Router in and it shows Downstream Margin and not SNR . Are these the same thing?

Old DLink DSL504 Downstream Att 33 SNR 11.5
New LinkSys WAG200 (_ new filter) Downstream Att 32 Downstream Margin 26
On 1MB ADSL

Is Downstream Margin the same as SNR - I need to try and work out what my new SNR is so can predict the max speed.

thanks

Well, yes and no. A few routers show the margin as being the number of dB over that required to make a stable connection, rather than raw dB's, but although many don't, the "margin" thing has stuck. I wouldn't worry about it - the difference is only 2 to 3 dB anyway.

33dB attenuation should give you at least 6 Mbps, but a lot depends on line noise.

Thanks

After much debate thought & research probably going to join you on Zen

In reply to:

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Are these the same thing?

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Yes. Almost everything reports the SNR margin or Noise margin against a value defined in the standards. The actual SNR is probably well over 20.

I look forward to seeing you in the Zen forum

In reply to:

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Yes. Almost everything reports the SNR margin or Noise margin against a value defined in the standards. The actual SNR is probably well over 20

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As I understand it, if you are on BT's default 6 dB SNR and your margin is shown as 6 dB then you are actually on 12 dB in reality.

If your SNR margin falls to 0 dB then you are still on 6 dB in reality and when you go into a negative SNR then you start to eat at your 'real' SNR.

Someone please correct if me if I'm wrong but this is how I think it works?