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[GigabitEthernet]

How do they connect the JDSU to the line when they're tracing a fault a long a line? I've always wondered this.

[GigabitEthernet]

I want this line!

[NewtronStar]

How do they connect the JDSU to the line when they're tracing a fault a long a line? I've always wondered this.

Via the Master Socket thats all it's supposed to connect to 

[GigabitEthernet]

Via the Master Socket thats all it's supposed to connect to 

No I meant if they're out repairing a fault can they not connect equipment to the line at a joint or something?

[NewtronStar]

Via the Master Socket thats all it's supposed to connect to 

No I meant if they're out repairing a fault can they not connect equipment to the line at a joint or something?

As far as i can see the JDSU will show a fault on the line when connected to your master socket it should show where on the circuit be it 0.5 meters or 1km away and further.

[GigabitEthernet]

And how does it do that?

[NewtronStar]

And how does it do that?

Reflected Pulse you need to talk to Burakkucat for more information 

[GigabitEthernet]

I know FECs aren't important in terms of DLM but I'm wondering if the amount on my line might be yet another indication of an underlying issue?

Is 348514 FECs in nearly 9 hours excessive? In that time we've also had 76 CRCs and 28 ES - this is on the downstream.

The upstream reports 76221 FECs in the same time period.

[les-70]

  I remain of the view that it is hard to be sure whether your line has a mild fault that Openreach has not picked up or whether you just have a rather noisy environment influencing the line.  Could you post the bit loading per tone when the SNRM is a max - typically in the day and also when it is a minimum say ~21:00 in the evening.  I am wondering whether it is possible to spot any signature in the change in bits per tone.

 It would also be good to see what happens if you use the RF3 and what difference, if any, it makes.   From my own experience i suspect that you won't be able to better the HG612 for error rates.   Other modems may give a better sync but they can also give higher error rates.

[GigabitEthernet]

The thing is that we're in a very quiet semi-rural area.

There is nothing between us and the cabinet that immediately pops out as being a source of interference. There is a pub but since the interference appears to be there all the time, not just when the pub is open, would seem to indicate that that isn't the cause.

The fact that previous fault tests have picked up a seemingly intermittent fault that magically goes away would seem to indicate an issue of some kind. The telephone line has been crackly in the past (I didn't actually know about this but other family members have indicated this) so this would seem to indicate some external issue.

I remain puzzled by the missing upstream tones because as has been said by others, the graph is looking quite healthy when suddenly all the tones just vanish.

[tbailey2]

Could you post the bit loading per tone when the SNRM is a max - typically in the day and also when it is a minimum say ~21:00 in the evening.  I am wondering whether it is possible to spot any signature in the change in bits per tone.

Here you go .. anyone can do this if they want....

[GigabitEthernet]

The strange thing about my line is that with only half (?) the tones for the upstream being available, the upstream is still syncing at almost 8Mb.

Looking at other lines with similar attenuations, some achieve lower upstream syncs with more tones available.

Can the modem dedicate more power to the tones that are available? I remember previously it was stated that the bitloading is better on the tones that are available.

[les-70]

  Tony's helpful addition has both educated me and answered my question - thanks Tony.   Looking at the bits per tone it looks like it is the higher frequency band that being hit most in the evening and with a dip towards the highest frequencies that are used.  That does make it look like RF noise but an indication of such noise can mean lots of noise about or a line which is prone to picking what ever noise there is.  Usually indicated by poor AC balance -- which the engineer ruled out.   

   As you say the absence of any bit loading at all in the higher frequency upstream band is odd given the preceding bit loading in the downstream band.

   Not much help I am afraid but the slow drifts in SNRM up and down do seem to be RF noise and not cross talk.   If and it is a big if, the noise is common mode, the RF3 should help but often the noise is not common mode.

[GigabitEthernet]

I still couldn't get the RF3 to work and I tried multiple cables

I'll see if I can get the engineer to fit one on Monday.

[GigabitEthernet]

Usually indicated by poor AC balance -- which the engineer ruled out.   

The particular test he ran passed yes but the issue I believe to be intermittent (TalkTalk did have one failed line test for instance, as did Plusnet a few years ago).

I'm just going to try my best to get the engineer to do a D-side change which he may or may not do