Attenuation versus distance from exchange?

Has someone got a table of average attenuations versus 'as the crow flies' distances from an exchange? I know the parameters will vary according to the number of cable joints, general age and state of the copper or aluminium conductors etc. Would BT do any maintenance work if my attenuation was way above average?

My modem Status:
Connection Status Connected
Upstream Rate (Kbps) 448
Downstream Rate (Kbps) 6080
US Margin 23
DS Margin 10
Modulation MMODE
LOS Errors 0
DS Line Attenuation 21
US Line Attenuation 24
Path Mode Interleaved

I used to sync at 8126 as I'm only 312 m from exchange but sync has dropped to 6080 recently.

TIA for replies

Nick

originally BT used to approximate 10 dB to the km, probably measured at 300 kHz. So the 5.5 km distance limit was a 55 dB attenuation, etc.

My line is 2.5km (I can follow it along its length) and one pair has an attenuation of 37 dB and the other 33 dB measured by router at 8128k. This suggests 13-15 dB per km.

You'll only get maintenance if there's a fault reported (speed less than 288 for example !)

It doesn't answer the question, (but may point to a problem which is causing the low speed), but the downstream and upstream attenuation figures are incompatible with each other.

What do you get with the router connected to the test socket inside the master socket, using just the short ADSL cable and a couple of different filters?

I would work out at 14-17db per km.

the lower figures I seen banded about like the 10db yarwell quoted seems far off reality.

I would think from that you would get the full 8Mb, i have similar stats and can get 8Mb on regular ADSL

Hi

DS Line Attenuation 21
US Line Attenuation 24

The upstream attenuation seems odd . It is unusual to have thUS Higher than th DS attenuation. Normally the US is about Half of the Ds (upstream lower frequency ). Just wondering if this indicates a problem that is only affecting Low frequencies . Not enough to reduce the US synch ,but reducing the BIN loading of the DS frequncies .Might be worth checking that your internal wiring has not developed a problem. There will be some loss to your DS synch ,It looks as if your Target SNR is at Least 9db.
Regards Jeff

Doing as the crow flies is worthless, as the answer will vary from exchange to exchange as cable routing will vary based on local geography

Currently BT Openreach only has to meet a 28Kbps USO, the newer 2Meg USO is not statute yet, and BT may not have to abide by it if an alternative is available (e.g. wireless/satellite)

In reply to a post by MrSaffron:

Doing as the crow flies is worthless, as the answer will vary from exchange to exchange as cable routing will vary based on local geography

Currently BT Openreach only has to meet a 28Kbps USO, the newer 2Meg USO is not statute yet, and BT may not have to abide by it if an alternative is available (e.g. wireless/satellite)

Good old Lord Carter. It does you good to laugh.

I don't see the 2Meg thing being a legal USO in the way we're used to. It isn't going to be an Obligation on a particular provider, the wording tends to be along the lines "delivering a universally available broadband in the UK by 2012 through a public fund, including funds released from the digital television switchover help scheme;" and will be the repsonsibility of the �Network Design and Procurement Group� not a particular operator or group of operators.

Bear in mind that the diagnosis of the problem is as follows:

Problematic home wiring (c.1.9m homes);
Telephone line too long (c.550k homes);
Random network effects (c.300k homes).

It is going to be a woolier concept for sure, and the NDPG is still an unknown. Also the report mentioned that for some areas accepting 1 to 1.5Mbps from mobile would be OK.

Alas many people will want to keep email addresses etc, so there will be people remaining with ISP A rather than switching to get a faster speed.