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[Starman]

It is but it also says you line is still showing the effects of HR fault those RFI signal should not be penetrating the D-side unless the joint is impaired.

Yeah you are right but not like OR or PN would take any action if I reported it. Future line fault for another day I guess. Still useful information to keep an eye on.

[NewtronStar]

Yeah you are right but not like OR or PN would take any action if I reported it. Future line fault for another day I guess. Still useful information to keep an eye on.

I know how you feel and even had it come from the horses mouth an OR engineer our joint is badly corroded and is impairing all premises who use this distribution pole and nothing in my eyes is being done to rectify it, My guess is they want it to degrade to the point were it fails 

Openreach are supposed to look after their network and not neglect it.

[S.Stephenson]

What effect would having a UPS and resyncing during a power outage have?

I suppose I'd get a nice looking QLN graph, and be able to see what effect vectoring would have.

[S.Stephenson]

Noise margin Jumped again but didn't fall back to its original level, could this be due to DLM taking action on my crosstalker?

Also attached one showing last 10 days.

[WWWombat]

I was one of the first FTTC users connected to my cabinet back in 2011.

I didn't really see much in the way of crosstalk etc. until January 2013, when it gradually worsened in small steps for around 18 months.

See the attached animated gif for my connection.
QLN hasn't really worsened much since September 2014.

Up to tone 1500, that pretty much looks like a 1:1 ratio between dB change in the QLN vs dB change in SNR. With changes as high as 15 dB.

Above tone 1500, there seems to be much less interference, around 3dB ... but still not enough signal to actually use any of these tones.

That probably suggests that most of your crosstalk comes from people whose line also only achieves tone 1500 - with only a few disturbers on shorter lines.

The QLN graphs from before the SNRM reduction & after the connection resynced as mentioned in the above message are attached.

Those graphs perhaps demonstrate the effect a single disturber can have on QLN.

Indeed. I reckon on those differences being around 3dB, restricted mostly to D1 - though, of course, most of your speed comes from D1.

[WWWombat]

The distance between the PCP and the ECI cabinet is quite large compared to what I've seen elsewhere, I'd say it's around 50m.

I'm pretty sure I'm near the worst case for crosstalk as I've not seen anyone with my attenuation have such relatively low speeds.

It is a little worse than mine, but not by a huge amount; until your line, I don't think I'd come across anything noisier!

My PCP and FTTC cabs are about 5m apart; the line is only about 100m long altogether, and the D-side that feeds my DP must split off from any other D-sides (fed by the same cab) after around 25-30m.

On the downside, my drop wire runs along the side of a building from the DP, in parallel to a lot of others; the drop wire probably amounts to a third of the total line length.

I haven't figured out why this particular line just seems so noisy.

[WWWombat]

The problem with QLN is that it's never refreshed until there's a resync.

Always tricky to grab new QLN data when the modems are shouting at each other. Having QLN can help analyse situations, we do have to try to remember that we're not looking at live data. As yours shows, we can make some wrong assumptions.

[WWWombat]

Soon i'll be setting up a the NooElec NESDR Mini 2 USB RTL-SDR & ADS-B Receiver Set to look a the radio spectral graph but have done most of my testing using the handheld radio receiver and the QLN graphs and tones confirms the location from where the RFI comes from

http://www.amazon.co.uk/gp/product/B00P2UOU72?redirect=true&ref_=pe_1980281_98137581_em_1p_1_ti

Wow! The stuff you can get in a USB stick these days!

[WWWombat]

What effect would having a UPS and resyncing during a power outage have?

I suppose I'd get a nice looking QLN graph, and be able to see what effect vectoring would have.

Yes - you'd find out what the line would look like if you were the only subscriber in the world. You'd see how clean it would look from external RF, for example.

So, yes, it would also give you the baseline for the best environment that vectoring could hope to replicate.

[WWWombat]

Noise margin Jumped again but didn't fall back to its original level, could this be due to DLM taking action on my crosstalker?

Yes, I think it could show that - especially on downstream.

On upstream, things are slightly more complex, because the upstream power can be adjusted. I resynced today, and upstream power reduced by 0.6dB, reducing my attainable by 1Mbps (from 33 to 32). That probably had an impact on the neighbour's crosstalk - even without DLM changing anything.

[S.Stephenson]

My line is around 320-350 metres and the drop wire to the DP is only 20m, I must just have the worst pair in the bundle and/or a port in the cabinet prone to crosstalk.

I have now set up my UPS that'll last for like 2-3H so all I have to do is wait for a power cut and maybe even reboot the modem and then see what happens.

Question is how long does the battery in the cabinet last for....

Speaking of Power would you say 14.0 for 14.2At is high as Chrystalis has 4.8 PWR on 14.7?

[Starman]

Question is how long does the battery in the cabinet last for....

I can't say for definite but the few times I've dealt with an LV mains fault affecting OR FTTC cabs - I know OR engineers were visiting the cabinet daily to swap out the batteries.

[burakkucat]

Question is how long does the battery in the cabinet last for....

I can't say for definite but the few times I've dealt with an LV mains fault affecting OR FTTC cabs - I know OR engineers were visiting the cabinet daily to swap out the batteries.

I have a vague memory of reading of about 8 hours.

I'm sure Walter will probably be able to tell us what his Surrey clients have discovered and Black Sheep will be able to give us the "official line" on the subject.

[S.Stephenson]

Well it beats my backup time, generally when I do get a power cut its normally back within the hour.

My current plan is to wait for a power cut and resync the modem to see what it syncs at and hope it somehow holds on when the power is back on.

If nothing else it'll be interesting to see.

[burakkucat]

My current plan is to wait for a power cut and resync the modem to see what it syncs at and hope it somehow holds on when the power is back on.

If nothing else it'll be interesting to see.

Indeed, it will. I'm sure I won't be the only one interested to see the result.