Andy Dingley wrote:
On 4 Jan 2006 08:03:58 -0800, "Mark Carver"
wrote:

I'm puzzled as to your wiring, and how it got to be this way. What you
describe is typical of older wiring, but unusual for a line that has
been upgraded to ADSL.

Not at all. BT make no changes at all to the consumer's installation
when they enable ADSL. They normally don't even leave the exchange.

BT _may_ visit if they're installing ADSL, and they'll leave you with a
nice NTE5 and ADSL faceplate, which is a tidier job than plug-in
filters. I agree that they don't always visit (probably rarely), but
I'd thought that if records showed the premises to still be wired
without sockets then it would trigger this. My own ADSL install
involved 3 visits by two different engineers , and that was hardly early
days.

I' d still say it's rare. Certainly not seen many examples of your
experience in uk.telecom.broadband, but YMDV :-)


As to ADSL wiring beyond the filter then this is possible, but it will
involve extra plug-in connectors in the ADSL path. I've had to much
trouble with these in the past and I'd rather do it by hard wiring as
much as possible.

Which you can do now with the Clarity master filter which has Krone
terminals for both filtered and unfiltered feeds. Of course the
unfiltered ADSL feed is just that, it's the twisted pair from the
'outside world' presented to the terminals and nothing more. Where
people run into trouble is having non twisted wiring (predominately
plug in telephone extension leads from DIY sheds) feeding their ADSL
modems. This can seriously degrade the SNR (particularly if the cables
run near or alongside mains wiring) [1] and in turn lead to reduced
performance. Providing you extend your internal network using telecom
grade twisted pair cable there should be no drop in performance. After
all think of all the Krone blocks and damp green boxes your line passes
through before reaching your home, another 10, 20, or even 50 metres
and and couple more clean and dry Krones will make no difference at
all.

[1] My ADSL router is 5 metres from my master socket filter. It's fed
by twisted pair BT cable. SNR reads 19 dB. If I replace that cable
with a B+Q extension lead SNR drops to 17dB. Connecting the router
directly at the master filter also gives 19dB.

(Downstream attenuation remains constant in all three conditions at
63.5 dB)

All IME, YMMV