Something plusnet dont seem able to get right..

A problem manifest with my line a few mnths ago and I'm wondering what the technical reasons bedhind it could be..

for many months before i'd have a script that rebooted my draytek router at midnight and at 7am, as without it i'd often find traffic would just stop flowing. everything else seemed fine in terms of sync speed, downstream snr etc.. it was like it wasnt a dsl link layer but a hgher up the tcp stack problem

around the start of feb, internet suddenly became very unreliable, with more than 50 disconnects or lost syncs per day and long periods that the router couldnt get sync. when on, syncing was at 256kb, normally 6.5mb

plusnet blamed my reboot script, saying the regular disconnects had caused their kit to see the line as unreliable and changed profile. they reset the line and told me to stop rebooting the router

i was still suffering slow speeds and eventually the took me off the restricted profile. internet was unreliable though SNR was fine at around 9

SNR gradually fell to 4 and internet became unreliable. an engineer visted and said the line was perfect, but he changed the faceplate and twiddled some screws anyway

since then i've had a merrygoround with plusnet where the snr drops to 0, i complain, they say theyll set the snr to 8 (how can you "set" the noise of a line?), it ends up at 4 and gradually drops to 0, i go on a restricted profile, snr goes up a bit, i complain of slow speeds, they unrestrict me, set the snr higher, reset the line, it craps out again..

i've had 4 different routers, 3 filters and wires and i'm plugged straight into the master socket..when snr was low but internet was functional i noticed that actually using it killed it.. i'd reboot the router, web would work fine, but watch youtube vids or start a torrent download and the whole thing would collapse in a heap minutes later. pinging google would take anything up to 3.5 seconds to respond even after other activities were stopped. at first i thought it was the router but 3 different models of draytek and a netgear all behave the same..


what complex interplay of issues is at work here? why do 4 different routers say my line has a poor snr, bt say its perfect, and the net works fine for light browsing but as soon as you hammer it, it claps out? snr now hovers around 1db no matter what PN say theyre gonna do with it.

is it relevant that i'm in an area that was supposed to be FTTC by mar 2012?

I have a similar issue on my Plusnet FTTC service.

The differences are that mine is an intermittent issue that usually lasts for a few days, then more or less disappears & that ISPs are unable to reset anything as DLM in the street cabinet has full control of connection profiles etc.

Basic engineer tests CAN & OFTEN DO report LTOK (Line Tests O.K.) due to the type of test.

Have you noticed an increase in line/signal attenuation that coincides with the start of this issue, or maybe switched to ADSL2+ which uses higher frequencies & is more sensitive to noise "interference"?

What you have described so far sounds like either "something" has massively increased noise levels, or that "something" (like increased attenuation) has massively decreased signal strength.

While connected at the master test socket, using a filter, does SNR alter or your connection drop when using a telephone?

The cause COULD be as simple as one dodgy joint (corrosion/water ingress etc.).
Basic tests will not always detect such an issue as voltage can still pass through, but a something like a TDR test MIGHT detect it.

Another cause COULD be a "bridge tap" that has been added to your cable (think of it as a sort of branch wire).
These tend to cause similar issues.

I have suffered similar issues for many months, the problem being that it is intermittent & has disappeared by the time Plusnet have been able to arrange an engineer's visit.

Your issue, as it appears to be permanently evident, might have a better chance of being located/fixed as it SHOULD be present if/when an engineer is instructed to carry out the "relevant" line tests.

FTTC Engineering enabling/preparation works MIGHT have disturbed a previously good cable/joint.

EDIT:

Would you be able to set up a monitoring program such as RouterStats that would graphically display how your connection performs (or doesn't perform) over a period of time?

Edited by deleted (Sat 31-Mar-12 08:44:59)

My bet is on the area getting WBC and ADSL2+ and this is showing up issues on the line, that ADSL tolerated.

Different modems handle ADSL/ADSL2+ differently, for example, a DG834GT on my line would reboot several times a day, but a DGN2200 held the line almost without fail.

It is worthing borrowing a friends modem just to see how things behave.

Interesting Mr Saffron, as both routers use a Broadcom 63xx series chipset.