Connections problem has me stumped ...

[Carol Haynes]

Here's the situation:

New BT Broadband 2.0 Hub/Router setup and working fine.

Desktop computer (Win XP SP3 Home) connecting wirelessly using a D-Link USB WiFi dongle. Browsing seems to work fine and often downloads are fine but some files stubbornly refuse to download past 90%.

I can download the offending files wirelessly on my laptop no problem but the Desktop just stops downloading and never completes. This seems to eliminate the connection which seems rock steady and fast on the laptop.

Things I have tried on the Desktop:

1) Installed the latest D-Link drivers - connection seems stable - 100% strength (only about 10 feet from the router).
2) Cleaned browser cache and flushed DNS cache.
3) Scanned (Malwarebytes and Avast Antivirus) and all seems clean.
4) Reset Winsock settings.
5) Used MSCONFIG to disable everything except MS services.
6) Checked HOSTS and Proxy settings - both are at standard windows settings.

Nothing seems to make any difference. There are no errors in Application or System logs (not even any warnings).

I just can't figure out what is happening on that computer to make downloads so difficult.

Anyone got any ideas please - I'm stumped!

[cmpm]

Could be Avast stopping, or slowing the download.
Or Malwarebytes website blocking, not sure.
Is Avast on the other computers?

Disable or remove Avast and try on a trusted file that was a problem.

Just a guess and a shot in the dark.
With your knowledge, you've done more then I could.

[skwire]

Different browsers exhibit the same issues?

[nudone]

it's not using one of those nvidia network drivers is it? if so, i'd blame that.

[Dormouse]

What do you use to download? Have you tried a download manager?

[40hz]

+1 w/Nudone on Nvidia drivers. I lost half a week on a desktop my sister owned due to network issues caused by those.

Also, are you plugged into a 1.1 or 2.0 USB socket? I have a Belkin USB wireless card that works beautifully as long as it's not in a version 1.1 port. If it is, it sporadically exhibits behaviors very similiar to what you're seeing: long files hang or abort towards the end of the download, but browsing always seems to work fine.

I never bothered to find out exactly what the problem was although I suspect it's either some sort of ack/nak lag issue due to the slower usb port, or some sort of buffer clog/overflow problem.

Either way, I installed a USB 2.0 card in the PC and the problem disappeared.

Try disabling the internal wifi on your laptop and see if plugging in the 'problem child' results in the same symptoms. If it does, you just might have a bum dongle.

Luck!

[4wd]

It's unlikely to be nvidia network drivers since the problem is on a computer that's connected via a DLink WiFi dongle is it not?

I've had a problem similar, Zyxel router/modem to a computer with a Netgear W111v2 - small transfers OK, large transfers just stop.  Even though signal is max the transfer rate was sub-500kB/s.

I can download the offending files wirelessly on my laptop no problem but the Desktop just stops downloading and never completes. This seems to eliminate the connection which seems rock steady and fast on the laptop.

-Carol Haynes (December 07, 2010, 10:57 AM)

But it doesn't eliminate the WiFi segment of the connection unless you are using the same DLink dongle for it as well.

There could be incompatibilities between the DLink dongle and the router - I would try the DLink dongle on the laptop to eliminate the WiFi segment and even then you can only eliminate it if the laptop is also running XP-SP3 so you can run the exact same driver.

Try another WiFi dongle also if you can.

Does transferring a large file over WiFi from laptop -> desktop, (and vv.), suffer the same problem?

[Carol Haynes]

To answer the questions (ish):

Avast on both computers - no probs on laptop.
Tried IE and Firefox - same problem. Tried download manager (same problem).
Not sure what LAN driver at the mo. - not using LAN but I suppose I could try disabling LAN.
Not sure whether it is USB 1.1 or 2 - have to check.
Using windows firewall - but no effect if it is disabled.

I'll have a look tomorrow at the LAN installed.

I wondered if it could be the D-Link USB WiFi adapter? It is about 5 years old apparently. Can't hink of a rational reason except that there is occasional flakiness to the connection (not consistent though). The same stalling downloads happened with the previous router - which was a D-Link so unlikely to be incompatible with a D-Link USB dongle.

Could it be mismatched packet sizes causing this sort of effect?

[Carol Haynes]

Does transferring a large file over WiFi from laptop -> desktop, (and vv.), suffer the same problem?

-4wd (December 07, 2010, 04:13 PM)

Haven't tried direct transfer across network but bothe computers have TeamViewer installed and I can transfer the files directly from laptop to desktop via the TeamViewer servers!!

[4wd]

Silly question but.....if it's a desktop computer that is only 3m from the hub why not just use a wired connection?

The BT Hub seems to include 4 LAN ports, (from info on the web), it'd be faster and more reliable.   Or are all the ports in use?

Someone's not microwaving popcorn when the transfers die are they?

[Carol Haynes]

Silly question but.....if it's a desktop computer that is only 3m from the hub why not just use a wired connection?

-4wd (December 07, 2010, 05:24 PM)

Geography - and there aren't spare sockets for powerline adaptors.

[Stoic Joker]

When the download stalls, does all network access stall with it? Or can you still load a webpage during a stalled download.

Reason I ask is that if everything slows to a crawl/stop at the same time you can use ping to identify where the problem exists. If you can ping the local ip address but not the gateway (router) then it's a WiFi issue. However if you can't ping the local IP or even the loopback address, then it's a LM/driver/protocol issue.

When you reset winSock did you reset TCP/IP also?

If IPV6 is an option on any of the equipment involved, disable it as it tends to be a real PITA and the root cause of all sorts of weird behavior & performance issues.

[Carol Haynes]

Web pages still load and other files will download - just the one stalled fie remains stalled.

No IPv6 in the network.

I didn't reset TCP/IP just Winsock - I'll give it a go.

Thanks guys for all the feedback - much appreciated.

[mrainey]

Maybe run this tweak tool and see if it gives you any ideas?

http://www.dslreports.com/tweaks

[Shades]

The files that go wrong...do they have a size bigger than <value>? Do these files crash the first time, but the second time they manage to squeeze through?

In those cases I would suspect time-outs and package sizes.

[Stoic Joker]

Web pages still load and other files will download - just the one stalled fie remains stalled.

-Carol Haynes (December 07, 2010, 07:07 PM)

That kind of eliminates the network shutting down angle. But it would be interesting to see what copying a large file across the LAN to that machine would do.

If another machine can still DL the same file at the same time just fine, it doesn't look good for a server timeout either.

Any chance it something off-the-wall like a file system issue? - (I'd been pondering this for a bit but didn't want to say it) - Run chkdsk /r and a defrag and see if the behavior changes.