Internet sync speed drop at the same time each day

Hi
We live about 4 miles from the exchange, so is generally slow.
However between 15:00 and 16:00 the downstream sync rate drops from ~1400Kbps to around 350 Kbps, I only spotted this this after getting a better router and noticing the internet speed had increased by 4 fold but then dropped after a day. With the previous router I could barely load Google.
After noticing the speed drop resetting the router caused the sync speed to increase back up to 1400 ish and after about 6 hours ish the internet speed increased up from 0.2 Mb to 0.9Mb.

The router stats when it is working ok is:
............................. Upstream.........Downstream
Current Rate (Kbps)... 448 .................1344
Max Rate (Kbps)......... 908 ..................1440
SNR Margin (dB)......... 15 ...................10.1
Line Attenuation (dB)... 31 ...................57.4
Errors (Pkts) .................0....................... 0

Here is the log for that time, I've tried researching the errors but didn't really get anywhere.

2013-12-03 15:52:19 [3] PPP: ppp1 User request
2013-12-03 15:52:19 [3] PPP: ppp1 LCP down
2013-12-03 15:52:25 [3] PPP: ppp1 User request
2013-12-03 15:52:25 [3] PPP: ppp1
2013-12-03 15:53:09 [3] PPP: ppp1 Timeout waiting for PADO packets
2013-12-03 15:53:09 [3] PPP: ppp1

The router is a TP-link W-8970 and we are using ADSL1 with AOL.

Any ideas on what the problem could be?

Cheers for any help
Owen

Install Router Stats Lite and run it for 24 hours with 30 second updates - plotting both sync speed and SNR for up and down.

Host the images on a suitable site, then post a link here. That will show what is happening and when.

In reply to a post by owendev:

We live about 4 miles from the exchange, so is generally slow.

Attenuation indicates line length is 4.1 km, so exchange must be < 2.5 miles away. Sure right exchange?

On that line ADSL1 should get 3.2 Meg.

I live in the middle of the countryside, but just double checked the exchange is exactly 4.5 miles by road. I know I should be getting a bit faster than 1 meg but at the moment I'm happy just getting your standard webpage loading in under 40 seconds.

As for the routerstats software, it doesn't like my router, so had to use the user defined settings, which the software just gave me the login page script, no matter what URL was entered.

I have plugged in the old router as that one works with routerstats. I'll post that data in 24 hours give or take a bit.

Cheers for the replies
Owen

Hi again
Here is a picture of the Rx-Noise margin which was the only thing that changed.
http://postimg.org/image/7nh4h0rmt/


Tx-Noise=14.0
Rx-Sync=1120
Tx-Sync=448

This is with the old router, which oddly the sync speed didn't drop for a change. Though does run slower.
But the the new router sync drops at the same time there is a large shift in the SNR margin, at 15:54 and 08:22.

Is this likely to be the new router being too sensitive, in which case is there a setting somewhere to change.

Cheers
Owen

I would guess that something somewhere is switching at 08:20 and 16:00 ... could be in the house or a neighbour or a street light ...

Thoughts - it is something that is electrically very noisy and at 8:20 AM when it turns off there is enough noise to totally fill the line for a very short period and sync is lost. As the noise source has, by then, disappeared you resync at 9dB. The 9dB has been set because of line issues.

At 16:20 the same device turns on and kills sync, then for the next few seconds it still creates a lot of noise which is when sync is being negotiated. It actually syncs at 9dB, but the noise then drops off a little resulting in the 13dB level ....


The overnight drift from 13 to 9 and back to 12 is quite normal - there is more background noise at night.

Run it for a few more days and see if it happens at the same time. On one day, try doing a manual resync at around 21:00

I don't think you mentioned what the original router is?
See the link in my signature - router choice (chipset) can make a massive difference on longer lines.

That afternoon spike is just as darkness falls so is expected - but as others are saying it could be connected with equipment being turned on at the same time.

I live in a village with about 10 houses in it and 5 miles from the nearest pub let alone anything else, so figuring out what is switching off and on is fairly easy.

We have 4KW of solar panels which are tied into the houses electrical grid and the two times coincide with sunrise and sunset and within a couple of minutes of the solar panels. So I imagine that when the inverter switches on and off it sends a pulse of some type through the electrical grid.

Though oddly the SNR ratio goes up when the inverter switches off and goes down when the inverter switches on.

Just a thought as to why the there is more interference when the panel are off, on mains power our house gets lots of power cuts and fluctuations in power, so when we are on mains there is more interference but the solar panel inverter is new and only 20m away from the house so provides a 'smoother' current and therefore less interference.

I have no real electrical knowledge so it's a guess as to how electricity works.

I'll give the installers of the solar panels a call and see what they can do as it's their installation.

cheers

The original (old) router is a netgear dg834pn and the replacement is a TP-link TD-W8970

I never thought about chipsets and all the other variables of the router other than good price, good reviews and being faster than the old one. live and learn

Cheers

SNR going up when the inverter switches off suggests that the inverter is very noisy and creating interference. Inverters do create quite a lot and that is transmitted through te cables and can either be radiated or picked up by the modem or modem power supply.

A higher SNR - Signal to Noise ratio means that the noise is lower so a greater difference between the two.. Your "Oddly" comment shows your understanding is reversed.