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[boost]

Engineer is here.

AC balance was fine, all tests on his JDSU passed, so he's trying to build a REIN case.

What was the figure?

[GigabitEthernet]

What was the figure?

59 I think?

[GigabitEthernet]

I just had a thought: if I purchase a JDSU I could constantly monitor the connection and then that might help in the fault diagnosis?

[roseway]

You could, but wouldn't you want to use your internet connection?

[GigabitEthernet]

I've got a backup 4G connection

I'd just like to know if it would work?

[lf2k]

However, the Hlog still looks odd.

Howdy - scraped some numbers from MDWS and put together this little graph, comparing your HLOG with a couple of others (hope BE1 and Kitz don't mind me picking on them!).

The "problem" with the graphs on MDWS is that if you flick between users and compare, they're not on the same scale.

By picking people with different attainable speeds (forgetting interleaving etc), you can see (hopefully) that this probably shows where the useful tones are.  What you really want is a continuous line (like Kitz) - where it starts to look "spotty" they're probably tones that cannot be used.

So, in a round about way, your HLOG isn't really odd it just shows you have a longer line than Kitz or me, and a shorter line than BE1 (or at least that's how I read it).

[les-70]

  Given that your line passed tests I don't think you would learn much that can't seen from running and using your connection.  The SNRM is giving an indications of the varying noise and any attenuation changes can be seen. Bitswaps per tone in DSlstats are a guide to troublesome frequencies.

 As I mentioned before you could try using an RF3 to see if that helps.  If the noise is common mode noise it will give some improvement through noise reduction.  If the noise is differential mode then there will be no improvement and all it will do is cost you about 1Mb/s.   Some engineers would have fitted one in case it helped.

[lf2k]

Les, looking at the graph I posted, do you know what the "cut off" dB would be for HLOG/useful tones?

I suspect that the modem is super sensitive and can register things below -80dB but there's insufficient headroom to do anything useful at those frequencies.

In which case we should discount anything below the -80dB line - and then it doesn't look noisy as such, it's just a long line.

Can anyone else shed any light on this?

*edit*
Just checked the bit loading vs dB on the HLOG.  It seems that (dependent upon frequency) the cut off for getting a "bit" per tone seems to be in the region -65 (higher tone) to -68dB (lower tone).

[GigabitEthernet]

Is 750m considered long?

[lf2k]

I'm not sure if 750M is long or not - but it's longer than (say) Kitz's or my line (about 500-600M).  Everything is relative and speeds tend to "fall off" the longer the line more quickly than with ADSL.

I might be wrong, but I seem to recall BE1 is about 1200M from the cabinet.

[GigabitEthernet]

Oh I see, yes that makes sense then.

I think what I'll do is to get another modem (Billion 8800NL I think) to see if that handles the noise any better and perhaps I'll consider getting the JDSU, just out of curiosity really

[burakkucat]

I just had a thought: if I purchase a JDSU I could constantly monitor the connection and then that might help in the fault diagnosis?

You could. A JDSU HST-3000c can be configured to act in place of the CPE (modem) and with two Ethernet patch cables you would be able to use the service whilst monitoring it. (I believe the same is true for an Exfo AXS-200/635.)

However are you prepared to pay £thousands for a new device or a significant number of £hundreds for a used device via, say, eBay? 

An example: Exfo AXS-200/635. Three examples: JDSU HST-3000c, No 1, JDSU HST-3000c, No 2 and JDSU HST-3000c, No 3. 

[GigabitEthernet]

Does this look okay, burakkucat?

http://www.ebay.co.uk/itm/jdsu-hst-3000-Bt-Telecom-Tester-/271894200837

[burakkucat]

Does this look okay, burakkucat?

http://www.ebay.co.uk/itm/jdsu-hst-3000-Bt-Telecom-Tester-/271894200837

At a quick glance and without sight of any precise details other than "Used for copper and fibre installs" (there is no mention of which SIM is included) I will tentatively say "Yes".

[GigabitEthernet]

Sorry, SIM?