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[sherlock]

Hi

I have been a BT Broadband customer for just over a year using their HH3 router. Mine is a simple setup with a laptop connected (until now) WiFi to router. No other equipment connected to it. The line socket is the BT master with test socket behind but my connection is to the outer (wall plate) socket.

After initial 10 day settling-in period (Jan 2013) with router on 24/7 I then switched router off every night. D/load speed initially 1.75 Mb but over the year gradually increasing. By Dec '13/Jan'14 typical speed was 3.5 Mbps, burst 3.9 Mbps.

By coincidence at time of renewing contract/package (phone & bb) end of Jan 2014 with new package starting 6th Feb my download speed slumped to 0.5 Mbps. I contacted BT who said they would change my connection but nothing has happened.

I first disabled WiFi and connected the laptop by LAN to HH3.

I checked my stats and line status. There is no problem with line and no line problems in my area. My test and Profile is:
Download speed achieved during the test was - 0.5 Mbps
 For your connection, the acceptable range of speeds is 0.05 Mbps-0.5 Mbps.
 Additional Information:
 Your DSL Connection Rate :0.61 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
 IP Profile for your line is - 0.5 Mbps

My ADSL settings indicate an attenuation of 4.8, and your own speed calculation arrived at between 5 and 6 Mbps potential.

Noise margin is 11.2 dB which other forum sources told me is the cause of dropped speed and that the margin should be 6.0 dB. I was advised to keep my router on 24/7 - and this I did 2 days ago.

However today I found the router had been restarted at around 3.45 am, and a later test showed it had been restarted again at around 11.50 am.

I am at a total loss to understand:
1) why my line capability of 3.5Mb sustained over several months has slumped 86% to 0.5 Mb
2) why my router is being remotely switched off and on, preventing me from even going through the 10 day settling-in DLM process (not that it should need settling in as an ongoing user, not a new customer)

If you can throw any light on this conundrum and what my options are, I shall be very grateful.

[JGO]

"Noise margin is 11.2 dB which other forum sources told me is the cause of dropped speed and that the margin should be 6.0 dB."

A high noise margin can certainly slow you down. BUT why did it happen ?

When I first started ADSL,  my noise margin limit  was ramped up to, 15 dB presumably by BT,  because of interference,  to make it "stable".  When the noise level was reduced (filtered faceplate etc) the limit is NOT reduced automatically - the so called 15 dB trap.

When my ISP leaned on BT to reduce it, the speed was doubled. This was complicated in my case because it seems the actual margin set was higher than the setting indicated (BT firmware corrupt ?)

Your restarts may well be the strong bursts of interference responsible.

Good Luck

P.S.  attenuation of 4.8 dB ?? at 13db/km  that says you are some 200 - 300 m from the exchange ? or is it 48 ? - ties in better with 5 -6 Mb/zec.

[sherlock]

Hi JGO

Yes my attenuation figure is a typo, and should have read 44.8 so rounded 45 dB.

As to why my noise rose I haven't the faintest idea. I have never had the need to check my BT statistics until now as I've never had this problem before.

Other forum advice was to leave router on continuously, one said for 5 days, another for 10 days. I went through this 10-day procedure over a year ago to then set up the HH3 router. This time around, after 2 days the router has been remotely switched off and on because readings I've taken show it was restarted twice today, and neither was due to power outages.

I've carried out Quiet Line Tests twice with no noise whatsover on a corded phone.

I can only hope router remains connected long enough for BT's Dynamic Line System to gradually rebalance my IP profile of 0.5 Mbps and give me back at least some, if not all of the 3.5 Mbps download speed I had until 3 weeks ago.

[JGO]

I suggest monitoring software, such as Routerstats may help you.   The point is that if the actual noise level rises for any length of time, the DLM corrects the increasing error rate by increasing the noise margin in 3 dB steps, dropping speed. This means the extra S/N is needed from then on even if the noise level drops again, so the speed doesn't recover 100% even if the actual noise drops. So is your 11.2 due to a 12 dB margin being set ?

"Noise" doesn't mean audible noise, if the quiet line test shows anything then you are in real trouble !  Noise means any sort of interference in the ADSL bandwidth - this is real radio bandwidth in Hz, not IT people's bandwidth which means information rate ( to confuse people IMHO) Possible causes are a electric motor with a defective suppressor maybe in a 'fridge. For ADSL a portable radio tuned to about 612 kHz (because it is a quiet spot) may detect it.
 
Switching off your modem is interpreted by the DLM as a line fault (= noise) too, so a rule of thumb is don't do it more than once in 24 hrs - various opinions.
 
If your statistics show a S/N consistently high the margin this has been raised at the DLM and needs to be reduced again toward the starting point of 6 dB. Some routers allow you to DIY, otherwise you have to get BT to do it.

[sherlock]

Thanks for that, and I'm glad to say that I don't need to monitor anymore as I have traced the cause of my problem. It was down to noise as you say, as that percieved by DLM. In my case it was introduced by a corded bedroom phone replaced a few weeks ago. The old phone was connected to a wall socket via a filter on the end of a short cable, the filter obscured by furniture.

The new phone was replaced directly into the wall socket, at the time failing to remember there was a filter somewhere below out of sight!

During the 3-week problem period the noise margin was around 11.2/24.0 dB. It is currently 8.2/24 but my d/l speed has already risen from 0.5 to 3.0 Mb! If normal noise is 6.0 (although I don't know what mine was) and DLM continues to reduce noise level then the speed should increase even further over the next few days. Router uptime is now continuing without interruption.

It illustrates how easy it is for a simple change of domestic equipment or conditions to be overlooked where the complexities surrounding broadband speed are concerned. I have learned a valuable lesson and some very useful knowledge about broadband At my age (90 in 2 months time) it can be a trifle difficult to comprehend at times! Thanks for your advice.

[JGO]

[sherlock]

Yes - my wall socket filters are the dangly type as supplied by BT. It was the dangly filter out of sight that led to my temporary misfortune.

I had read of the filtered faceplate but with just two sockets - the master in lounge and extension in bedroom - I think all is now back to a happy medium without further change. I suspect I could cause more harm than good if I tried to replace those fine wires into a new faceplate even with the special tool so will let well alone!

With ageing populations and technology advancing at a disproportionate speed to human comprehension, tomorrow's world is becoming a minefield involving the most humble of domestic apparatus. The thought that my next fridge could become part of a botnet or the means to invade my privacy is less than comforting. Fortunately from previous work experience (and personal interests) I manage to keep up with ongoing technical changes. I was also taught to touch-type at school 75 years ago - another boon and something I have kept up ever since. Especially useful for e-mails/forums and other textual needs.

Having recently acquired a 7" tablet, not that I actually needed one but just to get in on the act, I find its touchscreen surprisingly easy to use. Maybe your USA friend could try one out?

[JGO]

Yes with only two sockets not that much to gain, or as the engineers proverb has it =
 " If it ain't bust don't fix it !"

"With ageing populations and technology advancing at a disproportionate speed to human comprehension, tomorrow's world is becoming a minefield involving the most humble of domestic apparatus." 
Yes,
 Possibly you have seen a report of possible malware takeover of appliances ?
Also there is the extra piece to Moore's Law, (about computer power expanding 2* every 10 years). This states that human stupidity expands to nullify any nett gain !
Certainly some designers are more interested in the aesthetics of their design than the usability by ordinary mortals.

 

[sherlock]

I'm pretty sure that Moore's law is now way behind the times, already said by some boffins to be on the point of collapse. Quantum computing where the bits are superpositioned as 0 or 1 at the same time will render the law obsolete.

Possible malware in appliances?  No - actual, if I am allowed to use a hyperlink here (or you can prefix your own http etc)  phys.org/news/2014-01-cyberattack-hacked-refrigerator.html reports where last month a large botnet was traced to internet connected appliances. And with Stuxnet on the loose - oh dear!

[Black Sheep]

[sherlock]

[Black Sheep]

I can't speak for others, but I find it fascinating how far we've leap-frogged with technology in such a relatively short amount of time. Your 'back-story' is testament to this fact.

Thank you very much for sharing, and there are quite a few others on this forum who can probably also add to the debate of, 'Then and now'.

PS...... where's my manners ?? Welcome to the site, Sherlock.