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[giverny]

Hi

I'm newish to ADSL Max (upgraded last November) and still learning this new world with the wierd BT rules of operation.

Most recently, I've had a stable connection synced non stop for some 30 days at 2016 downstream rate (getting fairly consistant 1.5mbps data rate downstream using speedtests). Today had a power failure and noticed that box (Orange Livebox) had resyned at a lower rate, circa 1500. Tried again but still only getting around 1700 sync

So, decided to bite the bullet and take the opportunity to tidy up all the computer wiring and the telephone sockets. Result (see below) box is now syncing slightly better at 2432 downstream. Ran a BT speed test and interestingly, the BRAS profile was temporaily reduced down to 1mbps data rate for a while (no doubt due to the poor syncs at 1500 and 1700), but within a couple of hours or so of achieving the higher sync, the profile has improved and is now stable at 2mpbs (I was expecting to have to wait 3 or even 6 days for this improvement).

Connection mode : G.DMT
Type : Interleave
Noise margin (dB) : 15.6
Attenuation (dB) : 53.0
Attainable download rate (kbps) : 2720
ADSL status : Connected

Downstream Upstream
Rate (kbps) 2432 448

Anyway sorry for waffling, my areas of lack of knowledge are:

1) I know I am a fair distance from the exchange (highish attenuation) so should I be expecting any better sync rates than this, or is this reasonable ?

2) key question - despite having had a stable connection for 30 days, my Noise Margin has not reduced from 15.6 - I thought the exchange reduced it by 3 every 14 days if the connection is stable. (I had a lot of problems/reboots during the 10 day test period so suspect this may be why I ended up with a high value to start with but was expecting it to start going down, now that connection is stable)

3) relative to 1 and 2 above, would a lower noise margin give me any chance of better sync rate ?

4) how can I tell whether having interleaving on is helping my stability, the Livebox does not seem to keep any details of error rates ? (does Interleaving on/off have any affect on improving sync speed or does it just affect the data throughput ? )

5) do sync speeds vary much according to what time of day you connect or good/bad weather etc ?

6) what is the difference in the Livebox stats between downstream rate and attainable download rate ?

Thanks for taking time to read this. Any bits of info appreciated. Sorry to ask so many questions in my first post.

Kevin

[roseway]

Hi Kevin, welcome to the forum.

1) It might be possible to get a faster connection with more attention to wiring and local noise sources. Have a read of http://www.kitz.co.uk/adsl/lowSNR.htm for some ideas.

2) This is rumoured to be the case, but actual results are not so easy to find.

3) Yes, connection speed and noise margin are interrelated - as one goes up the other goes down. A lower target noise margin would result in a higher sync speed. Several routers have the capability to force the target noise margin up or down, but I don't know about the Livebox.

4) Interleaving will almost certainly improve stability, and won't reduce your sync speed or data rate (unless you are on a good line with a sync speed of 8 Mbps, which you're obviously not).

5) The noise levels vary all the time, and tend to increase at night, due to interference from medium-wave radio stations and other things like street lights. The amount of variation depends on individual circumstances, but can be several dB. If you have overhead telephone lines, these can be affected by weather.

6) I think the difference is overheads.

Eric

[kitz]

2) key question - despite having had a stable connection for 30 days, my Noise Margin has not reduced from 15.6 - I thought the exchange reduced it by 3 every 14 days if the connection is stable.

This really is a weird one "supposed to" and "doing" are different things.
I know someone whose target SNR was being reduced every 14 days, and causing him pain, because hed just get stable, then it would upset things again.
Yet Ive seen other people wait over a month and nothing happen.

6) what is the difference in the Livebox stats between downstream rate and attainable download rate ?

Not sure on the livebox - roseway could be correct - and probably is if the figure is lower.
However on some routers its a crude estimation of the maximum speed that the line could acheive.