General Discussion
>> General Broadband Chatter

Pages in this thread: 1 | 2 | >> (show all)

Print Thread

marcusjclifford
(committed) Thu 12-Nov-15 19:39:38

Example of BT Openreach making phone lines worse.

[link to this post]

Aquiss Home 30
On Exchange ESSTC - via edinbugh-ipsc
Speedtouch 585v6 on BT Filtered Faceplate

MrSaffron
(staff) Thu 12-Nov-15 21:19:31

Re: Example of BT Openreach making phone lines worse.

[re: marcusjclifford] [link to this post]

And your downstream attenuation is what?

Andrew Ferguson, [email protected]
www.thinkbroadband.com
See if your ADSL stats are any good | UK broadband availability checker | Speed test for PC, tablets and mobiles

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.

Zarjaz
(eat-sleep-adslguide) Thu 12-Nov-15 22:03:50

Re: Example of BT Openreach making phone lines worse.

[re: marcusjclifford] [link to this post]

Use of split pairs would provide other symptoms, does your line show any of these ?

Zarjaz

marcusjclifford
(committed) Fri 13-Nov-15 10:10:44

Re: Example of BT Openreach making phone lines worse.

[re: MrSaffron] [link to this post]

38db - It was before and after.

The SNR graph of the tones shows a nice gentle curve so no specific frequencies are suffering, it's just a general large increase in signal noise caused by the crosstalk.

Aquiss Home 30
On Exchange ESSTC - via edinbugh-ipsc
Speedtouch 585v6 on BT Filtered Faceplate

marcusjclifford
(committed) Fri 13-Nov-15 10:11:24

Re: Example of BT Openreach making phone lines worse.

[re: Zarjaz] [link to this post]

What other symptoms should I be looking for?

Thanks

Aquiss Home 30
On Exchange ESSTC - via edinbugh-ipsc
Speedtouch 585v6 on BT Filtered Faceplate

MrSaffron
(staff) Fri 13-Nov-15 10:30:10

Re: Example of BT Openreach making phone lines worse.

[re: marcusjclifford] [link to this post]

The lack of noise rejection can impact on the voice side, so you should be hearing issues too I believe, hence why twisted pair was common decades before xDSL was considered.

Andrew Ferguson, [email protected]
www.thinkbroadband.com
See if your ADSL stats are any good | UK broadband availability checker | Speed test for PC, tablets and mobiles

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.

ian72
(eat-sleep-adslguide) Fri 13-Nov-15 11:01:07

Re: Example of BT Openreach making phone lines worse.

[re: MrSaffron] [link to this post]

In addition, given there was a power cut, there could be some serious noise coming from an electrical device somewhere that would not be operating whilst the power was down.

As a start, if I was the OP, I would flip the main breaker in the house (as the router is on UPS) and see if it makes any difference to the noise margin.

MrSaffron
(staff) Fri 13-Nov-15 11:04:13

Re: Example of BT Openreach making phone lines worse.

[re: ian72] [link to this post]

And if the noise margin flies up at that point to do a resync and see if the modem is happy to make use of the spare margin.

Possibly worth saying twisted pairs while good are NOT perfect at making xDSL services immune to noise. Some noise sources can still cause problems and that even applies if you go all out and use CAT5E

(edit as phone rang, and pressed post before reading to see if I made sense)

Andrew Ferguson, [email protected]
www.thinkbroadband.com
See if your ADSL stats are any good | UK broadband availability checker | Speed test for PC, tablets and mobiles

Edited by MrSaffron (Fri 13-Nov-15 13:04:30)

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.

ian72
(eat-sleep-adslguide) Fri 13-Nov-15 11:12:58

Re: Example of BT Openreach making phone lines worse.

[re: MrSaffron] [link to this post]

I am either very tired or your second sentence doesn't make much sense?

I think you mean that whilst good at reducing noise they aren't perfect and noise.

MHC
(sensei) Fri 13-Nov-15 12:43:46

Re: Example of BT Openreach making phone lines worse.

[re: marcusjclifford] [link to this post]

Why would they randomly connect to individual wires rather than a specific pair? If they did, then at the other end of the cable the job would be ten times worse trying to locate the two wires used.

And, if a BT tech was found to be working in that way, he would certainly have been dealt with and the terminations remade.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C

taurus excreta cerebrum vincit

MrSaffron
(staff) Fri 13-Nov-15 13:05:02

Re: Example of BT Openreach making phone lines worse.

[re: ian72] [link to this post]

The joy of answering phone, and pressing post thinking you had typed something else smile

Edit may make some sense.

Andrew Ferguson, [email protected]
www.thinkbroadband.com
See if your ADSL stats are any good | UK broadband availability checker | Speed test for PC, tablets and mobiles

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.

ian72
(eat-sleep-adslguide) Fri 13-Nov-15 13:24:15

Re: Example of BT Openreach making phone lines worse.

[re: MrSaffron] [link to this post]

RobertoS
(elder) Fri 13-Nov-15 14:02:24

Re: Example of BT Openreach making phone lines worse.

[re: ian72] [link to this post]

In reply to a post by ian72:
I am either very tired or your second sentence doesn't make much sense?

I think you mean that whilst good at reducing noise they aren't perfect and noise.

Ditto?

_{^{The indispensable man or woman passes from the scene, and what happens next is more or less the same thing as was happening before.}}
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 59997/15142kbps @ 600m. - BQM

ian72
(eat-sleep-adslguide) Fri 13-Nov-15 14:32:32

Re: Example of BT Openreach making phone lines worse.

[re: RobertoS] [link to this post]

LOL. Indeed. I had written more than that but deleted a load - obviously I should have deleted another 2 words... I said maybe I was tired wink

deleted
(deleted) Fri 13-Nov-15 15:10:24

Re: Example of BT Openreach making phone lines worse.

[re: ian72] [link to this post]

In reply to a post by ian72:
In addition, given there was a power cut, there could be some serious noise coming from an electrical device somewhere that would not be operating whilst the power was down.

As a start, if I was the OP, I would flip the main breaker in the house (as the router is on UPS) and see if it makes any difference to the noise margin.

Certainly a good start. My 3 local interference generating incidents were all faulty switched mode power supply units. The most ironic one was the plug-in wall wart PSU for an ADSL broadband router - the supply degraded over a couple of months to the point where sync was unobtainable for its owner. I replaced the PSU with a non faulty equivalent and problem solved for owner and me (living a street away - I'd seen 10dB or so of margin/equivalent speed lost) In all cases they produced a broad band (ha!) radio frequency spectrum of noise which had the consequence of decreasing the signal to noise ratio of the wanted broad band radio frequency carriers used for ADSL (&VDSL) - in other words all 'tones' were similarly affected.

It's not unheard of that UPS produce produce nasty mains waveforms (and harmonics)

deleted
(deleted) Sat 14-Nov-15 14:24:27

Re: Example of BT Openreach making phone lines worse.

[re: marcusjclifford] [link to this post]

"I know what they did... they didn't use correct pairs (twisted) and connected the wiring just to random wires in the bundle."

How would you know ? have you seen the joints close up ? if not how can you know for a fact ? Very unlikey to be spilt pairs but could well be "random jointing" but that does no harm.

Gadget
(committed) Sun 15-Nov-15 17:15:55

Re: Example of BT Openreach making phone lines worse.

[re: marcusjclifford] [link to this post]

possibly also worth asking the question if your UPS is a sine-wave or a filtered square-wave output - some (more expensive) UPS try to mimic the mains sine-wave output for exactly the reason of minimising noise.

MHC
(sensei) Sun 15-Nov-15 19:30:10

Re: Example of BT Openreach making phone lines worse.

[re: Gadget] [link to this post]

It would not be the UPS output causing problems as the OP says he saw a significant SNR improvement when power failed.

Any pointing at the UPS should be at the input side where the incoming 230v is converted down to a 12v DC (niminal) to charge the batteries - that power supply could be a good . That will be operational when powered up but quiet when there is a power cut.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C

taurus excreta cerebrum vincit

Zarjaz
(eat-sleep-adslguide) Sun 15-Nov-15 21:49:42

Re: Example of BT Openreach making phone lines worse.

[re: MrSaffron] [link to this post]

That's the one, overhearing.

Zarjaz

Pages in this thread: 1 | 2 | >> (show all)

Print Thread

Jump to