Variable download speeds - exchange or me?

[Wivelrod]

Hey,

I hope I can get some advise.

I'm on Home SuperMax, have been for a while now, and for a long time the connection was rock solid. I could download at around 780 kB/s at all times of the day.

In recent months though my connection has been getting increasingly iffy. Download speeds are often halved, mostly in evenings and what I would consider peak times.

My exchange (THOK) shows no congestion however.

A visit to http://test.speedtester.bt.com/ this evening yeilded:

Code Select Expand

Download speedachieved during the test was - 3705 Kbps
For your connection, the acceptable range of speeds is 1200-7150 Kbps.
Additional Information:
Your DSL Connection Rate :7616 Kbps(DOWN-STREAM), 832 Kbps(UP-STREAM)
IP Profile for your line is - 6500 Kbps

My router shows:

Code Select Expand


ADSL Link         Downstream Upstream
Connection Speed 7616 kbps 832 kbps
Line Attenuation 41.0 db 25.0 db
Noise Margin         6.1 db         11.0 db

I understand the Noise margin might be a little low, though I've had rock solid connection before.

What (if anything) should I try next? A new filter perhaps?

Any advice is appreciated. It's somewhat annoying that with some in the country getting faster and faster connection speeds (Cable, LLU, FTTC with BT pushing Infinity Ads down our throats), my connection is getting worse and I've no upgrade path available in my area...not for a long long time yet it seems!

[Steve]

I'm guessing the exchange unless you've got a wifi connection that's not performing well. The exchange details available on the internet are not entirely accurate,support should be able to tell you for certain whether or not your on a congested vp.

[armadillo]

bt speedtester is the only speed test BT will consider. But it is no use in showing you when congestion is occurring. Actually, it's not much of a guide to speed either.

Download networx
http://www.softperfect.com/products/networx/

I use the portable version as I prefer never to install anything that can be run without.

It has a speed graph.

Fire off some downloads of several largish files simultaneously and preferably from several different servers - e.g a video or two from somewhere and some podcasts from the BBC.

If your networx speed graph looks solid like this



then you are not suffering congestion at that time.

If it looks "combed" like this



then the line is congested.

In the congested case, you get close to your maximum speed but only in bursts when the data gets through. The average throughput, as measured by all speed testers, including networx, is reduced.  In the uncongested case, the data gets through constantly at maximum speed and the average is close to full speed.

By trying this test at various times, you can identify when congestion usually happens.

The BT speed test will itself be affected by exchange congestion and also by heavy loading of the BT speed test server. The exchange checker rarely seems to indicate congestion problems.  Perhaps BT need to have had thousands of reports of speed problems and analysed the pattern of bt speedtester reports before they will acknowledge any possibility of exchange congestion. Even so, they regard dial-up speeds as "normal". (Or am I being too harsh on BT?)
 

[Wivelrod]

Ahh, yes then thats it I guess. I've been using the Think Broadband monitor for a while and when I'm not able to max my line out it always look combed. I'm downloading something at the moment and it looks like this:



I'm assuming there isn't much I can do then? My area doesn't have LLU or Cable, and has around 2500 house holds, so the exchange is not a priority for upgrades. Thus no date for FTTC.

Thanks for the insight.

[armadillo]

Yes, that's a congested picture. There's probably nothing you can do except try to download your big files at off-peak times. Download managers are useful.  7pm to 11pm is usually the worst time. I normally find it is plain sailing from about 1am! If you get a congested pattern all the time, I don't know if idnet can get you shifted to a different VP. But it would probably have to be very bad close to all the time for that to be done. Otherwise you could easily end up on a worse VP. But I'm no expert in what idnet can do.

I too am in an area with no LLU, no cable, and no prospect of ever getting FTTC.

[Wivelrod]

Yes, I tend to download big files overnight any way (for off peak usage). Thought often I forget to turn off/change windows auto update and find the machine rebooted at 3am

What is more annoying is not being able to watch a 720p YouTube vid or steamed movie when the Exchange is busy, or just do a ad-hoc download. I fear is that as peoples demand for bandwidth increases (more and more HQ online content), the problem for the likes of us on exchanges like this will get worse and worse. But nothing we can do about it other than have a good gripe. Hehe.

Thanks again for the help

[armadillo]

Windows Auto Update is always off on my PC!

I have pretty well given up on 720p Youtube. Until mid December, there was a great Firefox extension that would download youtube mp4 vids so you could save and watch after download. But they have changed their coding so none of the downloaders will work any more. Streaming has never worked for me - too frustrating.

[.Griff.]

Yes, that's a congested picture.

Not necessarily.

You have to remember that when downloading something not only is your connection a key factor but also the source you are downloading it from. I could download a file from "Server X" and produce a graph with "hills and valleys" all over it. I could then download the same file one minute later from "Server B" and get a consistently smooth and flat graph.

I'm in no way dismissing your suggestion that it may be congestion rather I'm saying there's more to it than that and I don't believe you can simply look at a throughput graph and say with any certainty that the cause of erratic throughput is simply congestion.  

Congestion is much more likely to show itself via latency. The TBB QM is ideal in this situation.

[Wivelrod]

Hey Griff, thanks for your feedback.

I think I said that I'd been running the TBB meter for a while and that the graph always looks combed. That is no matter what download source (or sources) I'm using (I understand that speed depends on the source, the destination and everywhere in between).

No need to feel you are dismissing people opinions. I've come here for advice, so please give it freely.

If this other tool (TBB QM) will be of use, then I shall download it this evening and install it on my server which tends to be always on (though I'll stress I disconnect everything from the network bar one PC when testing bandwidth/speed ).

Cheers.

[tehidyman]

Download networx
http://www.softperfect.com/products/networx/

Does running this add to your download allowance by much?

[Bill]

If this other tool (TBB QM) will be of use, then I shall download it this evening and install it on my server

You don't download it- it's a server-side application that you set up and keep an eye on as required.

Details here:

http://www.thinkbroadband.com/ping

Only really works properly with a static IP.

[armadillo]

Not necessarily.

You have to remember that when downloading something not only is your connection a key factor but also the source you are downloading it from. I could download a file from "Server X" and produce a graph with "hills and valleys" all over it. I could then download the same file one minute later from "Server B" and get a consistently smooth and flat graph.

I absolutely agree. That's why I said that he should download multiple files simultaneously from several different servers and then display the graph. The picture he showed would be typical of congestion if it was when doing that, IMO. It is best to pick files from servers in different time zones. When I get a picture like that while downloading large files from the US, UK and Europe, simultaneously, I reckon I can be fairly clear that the likely cause is local congestion. The combing correlates well with local UK time.

[Wivelrod]

Thanks Bill.

I've set that up. I think my router is set to block pings though, so getting 100% loss. Will have to fix that when I get home this evening.

[armadillo]

Download networx
http://www.softperfect.com/products/networx/

Does running this add to your download allowance by much?

Not at all. It just sits on your machine and monitors throughput.

[armadillo]

Here's a nice illustration of the effect of too few servers, especially when you get a silly server.



Before the middle hump, there is a download of a large file from a slow server with a deliberate throttling policy. In the middle, there is a period of downloading also several files simultaneously from one fast server (with a little hiccup). After that, the download from the slow server continues as before.

I think the OP's main concern was to distinguish between slowness caused by his own machine and slowness caused by circumstances beyond his control. Exchange congestion and source server slowness would both be in the latter category.

[davej99]

I have a graphical & numerical traffic monitor sitting on my windows sidebar, just under CPU and memory dials. It is a really useful indicator of download conditions and I agree very much with what has been said that the shape of the envelope tells all.

A rectangular envelope, flat-lining at the max profile ceiling, indicates that the profile rather than congestion is the limiting factor. I set the graph Y-axis to my max profile of 7150, so I can see how my connection is performing. If my profile gets reduced I can see this straight away because the ceiling has fallen.

A spikey profile indicates congestion somewhere; download site, ISP, or exchange. When running a BT speed test 1, a spikey envelope indicates ISP or exchange congestion, or in the case of IDNET, just exchange congestion. You also begin to see why some speed testers are less than accurate, compared with BT, when you see speed drop outs not present in a BT test, or when you see that the download very short. Think broadband is longer; speedtest.net is shorter. It is also clear when download sites have problems, when you will often see very eratic, stop start behaviour, drop out, or a maximum envelope flat-lining below the profile ceiling. It is clear why a video stutters.

Because this little graph is running all the time you build up a picture of how certain sites behave, how your connection is running and the state of congestion, so changes become instantly obvious. You can also detect unexpected or nuisance activity, important if you are using a low bandwith gprs dongle.

Finally it tells me just how rubbish my home network is, why backups take so long and how slow it runs when moving many small files.

Update: Thanks Armadillo your graphics say much more than my words, especially the last one, that a beauty.

[Rik]

I rather liked your prose too, Dave.

[Wivelrod]

I rather liked your prose too, Dave.

Me too

Thanks!

I think I'm relatively confident from what you guys have been saying that it is the exchange. After all, when I tried to download a 2nd file from another source last night the bandwidth graph barely changed, and with just the one download going (from a source which I know people with super fast broadband have downloaded in minutes not hours), browsing the net felt like I was back on 56k. Clearly there was no overhead at that time.

I'll keep watching it and keep my fingers crossed (probably in vain) that it gets better instead of worse.

And I'll see what the TBB QM meter shows once I unblock ping on the modem/router.

[Rik]

Sadly, the usual situation with BT is that it gets worse before it gets better.

[armadillo]

Update: Thanks Armadillo your graphics say much more than my words, especially the last one, that a beauty.

Modern art  Thanks Dave. I liked your prose too.

[Wivelrod]

FWIW, I got the TBB QM meter running...

[RobertoS]

@Wivelrod
What does this checker say about your exchange?

[Wivelrod]

@Wivelrod
What does this checker say about your exchange?

Good question,

I didn't make it clear in my oridinal post that is was this site I used when I said "My exchange (THOK) shows no congestion.".

Thanks