Broadband speed slowing down. [Archive]

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Oldie

30-07-2009, 22:27

Hello All
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Machine spec: Year old fairly cheapish box. 4600 AM2 64bit chip, on-board graphic, sound, Ethernet card. Cat5 cable to Linksys router, cabled to silver NTL-100 cable modem. Running Ubuntu 9.04 64bit.
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Sorry if this has been asked before. I responded some time ago to the Virgin-Media email regarding the 2 to 10 Megabit upgrade and was told my modem was OK. I noticed the speed increase a couple of weeks ago. I've had a reliable 2 Megabit download option for some years with NTL and Virgin-Media. Since the upgrade to 10 Megabits I've had a problem with the connection speed slowing right down.

I've check the speed at broadbandwatchdog-co-uk. When I first turn on my computer it tests at over 6 Megabits but after the computer has been on for a few hours the connection slows right down to less than 512 kbs. I reboot my computer and cable modem and this increases my speed. I have another old box connected to the router as a backup and if I turn this on when the speed slows down it has the same problem.

So, I think the problem is probably not my end. Can anybody tell me why rebooting the modem cures the problem and why the speed slows down so much.

I hope I've given enough information. Regards to all.
Oldie.

Sephiroth

31-07-2009, 10:21

Usually re-booting "cures" a speed problem by resetting your line and then the errors build up again. Something in your line could be wrong. Can you log onto your modem and let us know the SNR ratio?

http://192.168.100.1 with user/Pw = root & root

Click on Downstream

Let us know the Power Level & SNR.

Oldie

31-07-2009, 10:54

Thank you for your response Sephiroth.

I've logged into modem. I didn't see a Downstream link to click but as soon as I logged-in the information included:
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Type : Ambit ETH/USB Combo Cable Modem
Cable modem : Ambit Cable Modem

Downstream Receive Power Level : -0.75 dBmv
Downstream SNR : 35.81 dB
Upstream Transmit Power Level : 47.00 dBmv
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I hope I've understood you correctly.

Oldie

Sephiroth

31-07-2009, 11:27

Your report is what I'd call top dead centre. The power levels and SNR are perfect.

It means also that the line back to VM isn't suspect in my eyes.

You mentioned that this happens after a few hours. Might you be into the VM throttling hours having regard for your usage?

http://allyours.virginmedia.com/html/internet/traffic.html

Oldie

31-07-2009, 12:10

Sephiroth

Thanks for the suggestion, I've looked at the traffic management chart on that page. I can't see I get anywhere near those maximum levels. My heaviest download would be BBC iPlayer stream and YouTube steaming. The thing is, I often spend hours writing CSS or a little Javascript (hours because I'm really slow at it) without much incoming traffic at all - apart from Internet Radio that is.

Anyway, thanks again for your help. I'll just have to keep rebooting to cure the problem. I switched to Linux about two years ago and I've read several times that Linux is so stable it's happy to run for years without a reboot, so it's a little irksome I have to use this method to solve the problem :-)

Oldie

Sephiroth

31-07-2009, 12:36

The internet radio won't take you anywhere near the throttle threshold.

Anyway, I checked out your broadbandwatchdog.co.uk speed test. It gave me 10% of what I'm really getting (verified by real download).

Try:
http://www.broadbandspeedchecker.co.uk/

Oldie

31-07-2009, 13:05

Sephiroth

That link recorded 8.56 Mbs download and .48 Mbs upload. Plenty fast enough for an oldie. It's when it slows down to treacle speed that's the problem. At least I have a better understanding of why a modem reboot seems to repair it. And that probably rules out throttling (sounds like something one might do to a noisy parrot).

Thanks again, I really appreciate your suggestions.

Oldie

Sephiroth

31-07-2009, 13:21

Did you try the other speed checker? Is there a difference? And what is your practical download speed as measured in a Save File dialogue box? Like a Router manual or something.

Speedtest.net is another one that reports wildly and I can't rely on it.

Oldie

31-07-2009, 14:11

Sephiroth

I appreciate what you're saying, but when the problem happens, pages load exceedingly slowly. That's when the original test gave me a 512 kbs download result. BBC iPlayer just stutters to a halt. As I said, it's like treacle. As for the download speed in a Save File dialogue box, wouldn't that depend upon the host server and routed path. I assume these speed test sites can somehow measure the speed regardless of congestion along the way. I'm aware that whatever band width Virgin Media offer me is only between my modem and the VM server. So I don't expect consistent performance from wherever data is served from. But again, treacle is my best description of what has happened on occasion lately. I'm not complaining by-the-way. I've spent most of my life without the Internet :-) In fact, before I got interested in computing, I used to have a life :-)

Oldie

Sephiroth

31-07-2009, 14:45

To go back to first principles and then move forward - what happens if you connect directly to the cable modem cutting out the router?

Thinking here is to eliminate components however iomprobable it at first seems.

Oldie

31-07-2009, 16:30

Sephiroth

I did think of that - and you are right of course - I should and will try it. However, as the only thing that has changed is the upgrade from VM, I thought it more likely this was where the issue lay. I've learned quite a bit today reading through the posts. I'll come back for more.

Oldie

fatassmichael

31-07-2009, 17:38

Oldie, you're best off phoning ts on 151 from a vm landline and asking for a modem replacement, the 100 series are garbage at the 10mb. you will be sent the ambit 256

Oldie

31-07-2009, 17:53

Michael

OK. That's a piece of advice I didn't expect. Thanks.

fatassmichael

31-07-2009, 17:58

no problem, if you read some of the posts on the 2 - 10 meg upgrade, most of the people who posted with 100, 120 and 200 model ambits had problems with speed, which was cured when a new modem was sent, quite surprised vm said a 100 model would be ok, considering its age and unreliability.

Oldie

31-07-2009, 18:25

Michael

I've just phoned 151, spoke to a very polite man. Told him of your advice from the Cable Forum and he said I will receive the new modem within 3 to 5 working days. Thank you and best regards.

Oldie

fatassmichael

02-08-2009, 19:12

glad to hear it Oldie, hopefully it will solve your issues

Oldie

03-08-2009, 21:32

Sephiroth

03-08-2009, 21:55

Thanks to help above I'm waiting for an Ambit 256 modem to arrive. I've been reading some other posts on installing the new modem and it looks as though it will connect to the DNS server when powered.

My question is that from the other posts it looks as though I need to go to https://autoreg.autoregister.net/ to register the new modem. I've had a quick look at that URL but it won't allow me to proceed past an OS warning telling me I need Windows or Mac. I'm using Ubuntu Linux and haven't a machine running Window or Mac.

I suspect I'm going to lose my connection so I'm asking for advice first. Please don't advise me to get Window or Mac. I love my Ubuntu box. :-)
if this is a registration requirement, get a friend/neighbour in who has a Windows laptop to do the business.

Peter_

03-08-2009, 22:15

Thanks to help above I'm waiting for an Ambit 256 modem to arrive. I've been reading some other posts on installing the new modem and it looks as though it will connect to the DNS server when powered.

My question is that from the other posts it looks as though I need to go to https://autoreg.autoregister.net/ to register the new modem. I've had a quick look at that URL but it won't allow me to proceed past an OS warning telling me I need Windows or Mac. I'm using Ubuntu Linux and haven't a machine running Window or Mac.

I suspect I'm going to lose my connection so I'm asking for advice first. Please don't advise me to get Window or Mac. I love my Ubuntu box. :-)
All you need to do when you receive your new modem is to call Quickstart on 0800 953 9500 and tell the HFC MAC address from the base of the modem which they will add to your account and send signals to it and within 5 minutes you will be back online.

The is no need whatsoever to use that link to activate your modem.

Oldie

03-08-2009, 22:21

Sephiroth, Moldova.

Thank you both very much. Much appreciated.