Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: parkdale on May 17, 2016, 06:26:12 PM

Title: Noisy Line - sorry if it's long and rambling
Post by: parkdale on May 17, 2016, 06:26:12 PM
I used to have a very quite line :blush: then I upgraded to 40Mb John Lewis BB (AKA Plusnet) and I was quite happy with the result see pic 8 June 15.
About 2 months ago I started hearing noise on the line (Voice) really annoying as well!! sounds like tearing paper with occasional Cat scratching thrown in for good measure.
Phoned JL tech dept (Plusnet) complained about it (Making sure that the noise was really bad so they could hear it as well ;) phoned between each visit ... yes can you hear it too!!
1st visit swap pair (no I said it's a voice issue) still hearing noise can you?
2nd visit plays with top of pole.... no change
3rd visit no noise found!!!
4th visit can't do anything cos neigbours wire hanging too low!! although plusnet found a copper joint impairment!
5th visit changed overhead wire to pole ( ::) wire was old style 2 core black sheath and been hit by lightning, frayed, repaired, relocated etc) tested new wire measured -55db on his tester with green lights across all tests. As he's putting his tools in the van, we run a quite line test, oh dear right at the end .... the noise came back! his face was a picture!, plugged his unit in, you can hear the noise and the line measured perfect!!!!!
6th visit today came in from work, did quite line test, no noise, looked at Fritz box stats no crc errors. But what caught my eye was available broadband speeds gone up by 10Mb!
have attached pics showing progress to date.
Well done Plusnet tech for keeping with it, as even their tests did not show any problem!
Realised wrong pic :-[
Title: Re: Noisy Line - sorry if it's long and rambling
Post by: NewtronStar on May 17, 2016, 08:17:51 PM
Its a pity it took 6 engineer visits to gain back 10mbps but I will salute you on your determination to get the noisy line fixed, I would have gave up after 3 visits  :blush: 
Title: Re: Noisy Line - sorry if it's long and rambling
Post by: burakkucat on May 18, 2016, 12:06:37 AM
A good result . . . eventually.  :)
Title: Re: Noisy Line - sorry if it's long and rambling
Post by: aesmith on May 18, 2016, 01:45:48 PM
... plugged his unit in, you can hear the noise and the line measured perfect!!!!!

Took them six visits to fix our noisy line as well.   Several of those visits were exactly as you say there, engineer agrees theres noise on the line but tester says it's OK.   To be fair the fifth visit would probably have fixed it if the guy had been equipped to deal with the heat sealed joints.
Title: Re: Noisy Line - sorry if it's long and rambling
Post by: parkdale on May 18, 2016, 05:52:49 PM
Have more info... visit 6 "Pair changed from PCP to joint at base of pole". :fingers:
So it's a waiting game now as to whether the noise has gone or not, hopefully I can get a word in during my conversations with my Dad (He's a bit mutton jeff ::))
So over the past nearly year i've got my Attenuation down by 2db and the potential line speed has got from 39Mb up to 55Mb.
Persistence pays in the long run...
Tried explaining to our cat the tech details of how broadband works ;D see pic below for interest level
Title: Re: Noisy Line - sorry if it's long and rambling
Post by: WWWombat on May 18, 2016, 06:23:02 PM
In all of those pictures, your line is showing that DLM has intervened, and set INP=3 and delay=8. That means it is using an error correction method on your line, eating some of your spare bandwidth. That's probably why your first photo shows a speed of 37.7Mbps.

It also means your latency is 8ms higher than without, so ping times will reflect this extra latency.

Hopefully, one hidden effect of the change will have been to reduce the errors (which you probably would have seen as a FEC count), and to allow DLM to de-intervene (setting INP and delay to zero).

If that happens, then your ping times should reduce. You might also see that "attainable" speed of 57Mbps reduce to around 49Mbps - a lot of modems estimate this value "optimistically" when DLM has intervened.