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[old bill]

Hi,
     First post here so hope I have this in the correct place. I recently switched over to Sky and wondered if my line stats were any good ?

DSL Connection Details
DSL Line (Wire Pair):   Line 1 (inner pair)
Protocol:   G.DMT2+ Annex A
Downstream Rate:   8190 kbps
Upstream Rate:   764 kbps
Channel:   Interleaved
Current Noise Margin:   7.7 dB (Downstream), 13.2 dB (Upstream)
Current Attenuation:   47.1 dB (Downstream), 26.9 dB (Upstream)
Current Output Power:   20.4 dBm (Downstream), 12.3 dBm (Upstream)
DSLAM Vendor Information:   Country: {0xFF} Vendor: {GSPN} Specific: {0x1000}
PVC Info:   0/38


Collected for 2 days 6:55:47
Since Reset   Current 24-Hour Interval   Current 15-Minute Interval   Time Since Last Event
ATM Cell Header Errors:   787   105   0   0:28:04
ATM Loss of Cell Delineation:   212   16   0   1:01:33
DSL Link Retrains:   1   0   0   1 day 12:45:28
DSL Training Errors:   1   0   0   2 days 6:55:10
DSL Training Timeouts:   0   0   0   0:00:00
DSL Loss of Framing Failures:   2   0   0   1 day 12:45:28
DSL Loss of Signal Failures:   2   0   0   1 day 12:45:28
DSL Loss of Power Failures:   0   0   0   0:00:00
DSL Loss of Margin Failures:   2   0   0   1 day 12:45:28
DSL Cumulative Errored Seconds:   428   66   0   0:28:04
DSL Severely Errored Seconds:   2   0   0   1 day 12:45:28
DSL Corrected Blocks:   17351   2292   54   0:00:03
DSL Uncorrected Blocks:   844   114   0   0:28:04
ISP Connection Establishment:   2   2   2   18:11:09


DSLAM:   Country: {0xFF} Vendor: {GSPN} Specific: {0x1000}   
DSL Line (Wire Pair):   Line 1 (inner pair)
Downstream Rate Cap:   8192 kbps
Downstream Atten. at 300kHz:   40.9 dB
Uncancelled Echo:   -17.1 dB   Ok
VCXO Frequency Offset:   -6.7 ppm   Ok
Final Rx Gain:   23.3 dB   Ok
Impulse Noise Comp. Tones:   0   Ok
Excessive Impulse Noise:   0   Ok
Impulse noise protection:   1.20
Delay of latency path:   15.25 ms

Thanks for any advice.

[roseway]

Hi old bill and welcome.

I would say that your stats are pretty good for your level of attenuation (47.1 dB). There's nothing really to comment on.

[old bill]

Hi,
    Thanks for the welcome. On basic ADSL (8meg) my attenuation is 42 ad I sync at 7616 on Sky. Sky have capped my line at 8190kbps is the best I am most likely to get or should I see if Sky will uncap my line ?

[kitz]

Hi Bill

As eric says for your attenuation (which relates to the length of your line), your sync speed is excellent.

Looking at your SNR Margin (7.7 dB), the default for most ISPs is around 6 - 6.5 dB therefore you dont really have that much "spare" to get that much additional speed.  SNR Margin normally changes throughout the day, and gets slightly worse in the evenings, so to be honest you are likely very near the maximum speed for your line as it is.

If sky uncapped your line, it may give you a couple of hundred kbps,
You could always ask... but the risk is that it may cause instability problems and/or dropped packets.
IMHO I think Sky have done the correct thing capping it where it is.

Saying that I take it you have already done all the usual things  to try and increase your SNR Margin?
http://www.kitz.co.uk/adsl/lowSNR.htm

[mr_chris]

Yeah, it would be worth following Kitz's advice and trying to get the best out of your line first, before seeing if it's a good idea to uncap it or not.

Your speed is excellent for your attenuation... compared to your 47dB attenuation, mine's 42dB on Be (also ADSL2+, same as you) and I sync at anywhere between 8 and 9Mbps depending on time of day, so you do seem to have a decent line anyway.

I would see what happens to your stats if you completely optimise your internal phone wiring

[setecio]

Your speed is excellent for your attenuation...

Is there a chart that converts attenuation into average expected line length so that it shows if there are other issues on a line causing a larger attenuation ?

eg showing for example with an attenuation of 40 dB, the average expected line length should be around  ? km .

[roseway]

In the UK the average attenuation is about 14 dB per kilometre, but it can vary quite a bit. So 40 dB would probably be a line length of just under 3 km.

As it happens, my attenuation is 42 dB, and I've measured the line length at 3 km (overhead lines which follow the road).

[kitz]

>> Is there a chart that converts attenuation into average expected line length so that it shows if there are other issues on a line causing a larger attenuation ?

There obviously anything accurate, due to the fact that SNR can also play a part into it.
Theres also the fact that some longer lines may have higher guage copper which will give better attenuation.. and also aluminium on some lines will have the opposite effect.

The nearest that I could find was the internode graph.  Although there are some "odd points".. on a whole it mostly is around 14dB.

Last year I coded a maximum speed calculator which was primarily based around the Internode data, it involved quite a bit of graph plotting.. and rechecking Richards linear calculations..  and then finally I spent about the best part of a day checking it against just about any UK line data I could and it did seem to work out within acceptable parameters.

So by all means try putting your attenuation in the Maximum speed calculator and it should return an approximate Line length.

Just bear in mind the caveats above.. and that the figures are based on attenuation readings at 300Khz.