Date   : Sun, 21 Mar 2010 19:27:42 +0100
From   : rick@... (Rick Murray)
Subject: [OT] ADSL capabilities

On 21/03/2010 08:25, Mike Tomlinson wrote:

> This would have been about 1985.

The hurricane was 1987, and this exchange was hardly a big urban area. 
It probably modernised circa Y2K. :-) Heck, I left boarding school in 
1990, and the phone numbers were still given as three digits after the 
town name, plus the payphones were clunky rotary-dial jobbies. Large 
solid metal things.


> Huge room, with two rows of pairs of batteries all wired up to
 > massive bare copper busbars that ran the length of the room just
 > above head height.

I bet it looked a lot more impressive when it wasn't mangled with trees...


 > Wouldn't like to be the one that dropped a tool in there :o)

Back in a past life I once shorted a car battery with a big spanner. 
Huge mistake. But an impressive one. :-)


> I think it's more likely that you have paid for an "up to 8MBps"
> service, which will negotiate the best speed it can given the line
> conditions.

Actually, the service is evolving "up to 20 mega", however your line is 
subcategorised as 1/8/20 megabit. As I am not eligible for 8 mbit, I get 
stuck with one. Sucks.


> A 4132Kbps sync sounds reasonable given your line length and
 > attenuation figures.

Yes, it's 3.5mbit to 4.2, depending on the weather.

Unfortunately I don't have the ability to speak to an engineer. A techie 
would understand that if the lower limit of quality for both 1mbit and 
8mbit lines is 512kbit, then what the hell can it hurt to switch to 
8megabit and sync around 4ish?
Tell that to a girl on the customer support, you'll get no further than 
"you are on one megabit because of the technical specification of your 
line". Say anything, they repeat that line ad finitum.


 > You could try a BT iPlate (I know you're in France, but it's all the 
same)

No it isn't. We run a two-line twisted pair into what might be the 
biggest phone plug on the planet. I think (distant hazy memory) the old 
BT system was designed to try to counteract bell tinkle when hanging up 
the phone?

The incoming line goes directly into the living room. It passes through 
a plug-in filter, and then a cord to the Livebox. Short of picking up 
and moving the house, there isn't much that can be changed with this setup.


 > and borrow a few different routers to try.

Mmmm, there's something of a lack of neighbours here. :-)


> Some are better at negotiating a higher sync speed than others.

I'd have thought a megabit wouldn't be too hard, given the Livebox says 
it can sync 3-4 times that. Smacks of a stupid arbitrary limit.


Best wises,

Rick.

-- 
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