FTTC serious slowdown evenings and weekends

I've just recently had BT Infinity installed. At first I was delighted with it (nearly 37 Mbps download), but over the past few weeks noticed a worrying pattern emerging. It seems that every evening and at weekends the speed drops significantly. For instance most of today and yesterday it's hovered around 3-4, apart from early this morning. When I check in the morning (7 am) the speed is always back at 34-37. I've tried replacing the HH3 with my own Netgear router and ran tests wire/wireless with the same result. Uploads are always rock solid at about 7-8.

Doing a bit of research I've come across various people mentioning congestion issues. I've no idea what technology is used here or where the congestion might occur (is it an issue at the local exchange) or more importantly what to do about it. I had a BT engineer around recently and he just checked the line and said everything was fine (which it was because he checked it at 2.00 on a Friday).

Any advice would be welcome.

Welcome to the forums .

Which exchange is it please? If you don't know, use this checker.

The engineer won't have been looking at through put speeds, just sync rates.

What results do you get from www.speedtester.bt.com on a wired connection ?

I'm on the Shrewsbury exchange

I just tried a bt speedtest wired, and it gave me a download speed of 0 (I'm guessing it's got some issues). I then tried the 'tap3' test (the one where you have you change your login) and it came out at 4Mbps. My ip profile is set to 38.71 Mbps. I tried it a few days ago when it was slow and the bt speedtest result more or less matched the speed I got wirelessly from speedtest.net, in this case around 7Mbps.

There was no reported congestion there on the last date I know of, but the latest report date is 11 March.

I've been getting exactly the same (I'm on the Banbury exchange).
Speed tests (no matter which speed test site I use) struggle to get above my old 4.5Mbps BE connection, yet as soon as we get outside of peak hours the speedtests are a rock-solid 37Mbps.

From August last year, through to a week or two ago, I used to get speed test results of 37Mbps irrespective of the time and day.

Going by many years experience (and regulars of these forums will have seen it many times before with the old ADSL products), there's little doubt in my mind it's either localised congestion (can't be national because the forums would be full of complaints) or BT are throttling web traffic on their Infinity product.
Or BT have a "bad boys" list and are throttling heavy (ish) downloaders.

My issue is definately not with my connection (sync'd at maximum speed and it only ever drops sync when I reboot the modem - it's easy to spot this with a large ISP like BT as your IP will most likely change when your modem re-syncs - between October last year and the begining of March this year, I had the same IP address).

If I set up a Usenet download it will go at maximum speed at any time of the day (even when speed testers give results of around 4Mbps for my 40Mbps connection).
Therefore it's unlikely to be congestion (if the networks - locally or nationally - were congested I wouldn't be getting full speed from Usenet).

Oddly enough it all started around the same time as BT started making 80Mbps connections available to new and existing customers (i.e. came out of any trial phase, and went into roll-out mode).

My money is on throttling.

EDIT: pings are rubbish too - just got 26ms to a server in Coventry (about 30 miles up the road and the one Speedtest/net selected as my closest server).
I normally get pings at (or just below) 10ms.

Edited by adebov (Sun 22-Apr-12 20:40:58)

I reckon BT Wholesale failed to anticipate the 80/20 takeup and the speed test servers aren't geared up for it.

As soon as a small amount of congestion appears on the WBC backhaul, which coped fine with 40/10, we all hit the speed testers. That worsens enormously the load on the backhaul, and also on the BT speed tester.

Result - mayhem!

Without speed testing the congestion may be manageable. Until we look at it using queuing theory.

Any idea how to distinguish deliberate throttling from congestion? I know BT throttle P2P at peak times but I've just tried going onto the thinkbroadband large file download section

http://www.thinkbroadband.com/download.html

And clicked on the 1GB file. It's offering up about 33 mins whereas yesterday morning it was about 2 mins. I can still watch iPlayer thank goodness, but it's worrying the speed has dropped so far.

Congestion should affect all protocols equally.

Throttling will just affect one or two things like torrents and newsgroups