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Bad SNR?

N/A

Bad SNR?

If I undersatnd it correctly, I think my SNR thingy is terrible.

Attenuation is 45 local and 19 remote

Margin is 5.5 Local and 11.5 remote.

Although this sucks I still seem to be getting decent speeds (448kbps up and approx 3.4mbps down). I'm about 2 miles from exchange (which is on another island and the cable runs under the sea).

Do these figures make sense?

Thanks again,

Oliver
9 REPLIES
Community Veteran
Posts: 14,469
Registered: 30-07-2007

Bad SNR?

What you are seeing is exactly what happens with MaxDSL. As your sync speed increases, your SNR decreases. BT put the lower limit on SNR of 6dB so it tries to sync at the best possible speed while still remaining at or above 6dB.

This is why your SNR is more critical with MaxDSL that previously which only used line attenuation. The higher your SNR to start with, the higher you will be able to sync at with MaxDSL and thus the faster you can receive data at.
N/A

Bad SNR?

Thanks. This makes sense! Just hope I can keep these good speeds up!

Oliver
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Bad SNR?

Has anybody any links to a calculator which could be used to work out the theoretical speed based on given stats?

eg:
DS Attn:48db
DS SNR: 10db

Speed likely to be in range Huh? to Huh?

Or if there is no online calculator about, does anybody know the formula to work it out?
shellsong
Grafter
Posts: 2,191
Registered: 03-08-2007

Bad SNR?

@sallyandjames

It depends on the speed at which the stats were measured because the SNR is speed related-- the rule of thumb is double the speed drops the SNR approximately 6dB although other factors can affect this that can be difficult to allow for

There is an online calculator at http://212.23.23.177/calc.htm
N/A

Bad SNR?

Hmmm looks like I'm right the the poo then - speed test this morning (06.30 when I made a note of the stats) was 60k Cheesy Cheesy
shellsong
Grafter
Posts: 2,191
Registered: 03-08-2007

Bad SNR?

It's the sync speed at the time your stats are measured that's important, not a speedtest result-- you should have been able to obtain it with the rest of the stats
N/A

Bad SNR?

Sync speed is 1Mb - anybody any ideas on how to work it out with the three nuggets of info?
shellsong
Grafter
Posts: 2,191
Registered: 03-08-2007

Bad SNR?

The calculator I linked to reckons 1139 Kbps, I think that's a bit pessimistic and somewhere around 1500Kbps is more like it-- you really could do with improving your SNR if at all possible!

See if http://www.kitz.co.uk/adsl/lowSNR.htm is of any help!
N/A

Bad SNR?

Sorry - going blind - completely missed your link - Thanks Cheesy