Is this Line Attenuation any good?

Technical Ben · Feb 20, 2011, 21:56:31

For my downstream it's
Noise Margin: 12.0 dB
Connection Rate: 8128 Kbps
Line Attenuation: 2.5 dB

Upstream is not as good...
Noise Margin: 22 dB
Connection Rate: 448 Kbps
Line Attenuation: 4.0 dB

It's always confused me, because all the sites quote 7meg speed download. Is it 7.15mbps? Yet BT/Wholesale quote "up to 8meg" on their adverts. I never get the "8" meg though. What IP profile would I need for "8meg"?
Is this just a mix up in bits and bytes. Or can I squeeze out an extra MB?

Steve · Feb 20, 2011, 22:06:31

You'll never get anymore as the IP profile limits you to a max of 7.15 Mbps on adslmax.

Technical Ben · Feb 20, 2011, 22:11:12

How is that "8meg" then?
Is "20meg" even that then? (advertised as 24meg by some)
I know it has a bit to do with overheads and the like. But it is very confusing. No wonder I could not squeeze any extra performance out of it.

Steve · Feb 20, 2011, 22:20:11

What I'm not sure is how the ATM and other overheads interact with your IP profile, on a non profiled system i.e LLU or Datastream in ideal world you should get nearer the 8Mb but as we know this is rarely if ever the case.

Technical Ben · Feb 20, 2011, 22:30:50

How can you advertise a line that is limited to 7.15mb as "up to 8". Or are they using rounding now?

This is purely a rhetorical question. As I know it's been discussed before. It's just that I only just realised I'm on the ceiling. I've been tweaking for 18 months looking for a better connection.

At least I am getting the best I can get. Now too sneak into the Exchange and turn the lables from "ASDLMAX" to "ASDL2+". When the engineer comes in to inspect, he will see it all needs "fixing".

Lance · Feb 20, 2011, 23:32:05

I thought you lived in the exchange to get that attenuation!

Technical Ben · Feb 21, 2011, 08:59:00

If it halves again, I get 14mb. Another drop I get 28mb! If it goes down to 0.0000001 I get a billion Mbps!*

*_{I guess the log scale is not the best scale to work with in reverse.}

Rik · Feb 21, 2011, 10:28:09

The short answer, Ben is that the advertised line speeds were originally always the maximum possible sync speed. Nowadays they are tending to quote the maximum throughput instead.