Network busy error copying large files

[wamontgomery]

I have an 802.11 network (Linksys BFW11S connected to a cable modem and 3 PCs with Linksys wireless cards), and have been using it with no problems until I tried to transfer large .wav files (200Mb) from one machine to another. The transfers work only one time in 10, the rest of the time it stops somewhere and usually gives me a "network busy" message. I can look at the network activity on either the linksys base station or on the PCs (using the lights on the cards or a system monitor), and all tell the same story -- the network transfer proceeds erratically, a few packets at a time and long delays inbetween. None of the machines have trouble reaching the cable modem and short files don't seem to be an issue. I've tried upgrading the firmware on all the machines and the base station with no effect. It looks like either some kind of flow control problem or like data is being lost in the wireless network and not properly recovered. I am usually sending from a Windows ME machine to a Windows XP machine during this, but I've seen the same problems XP to XP. I don't really know whether this is a LInksys problem or a Microsoft problem.

What else can I try?

[Greenstead]

It might be worthwhile to check everything is up-to-date (Linksys firmware and windows).

[wamontgomery]

Thanks, I downloaded new drivers and firmware and updated them a couple of weeks ago, though I really don't know that I did it right. The directions for installing drivers and other things on the PC connected cards (one is a WPC PCMCIA card and the other is a USB interface) aren't all that clear, and when I look at the dates on the drivers under windows they look old (a year ago, though that's more recent than my original purpose so it may just be that the most current driver is a year old).

I have installed all the OS and driver updates Microsoft windows update offers for all the machines.

Near as I can tell all the driver bindings look okay (MS file and printer sharing and client on TCP/IP, which is on the wireless network).

What really puzzles me is I regularly upload and download largish files (5 megabyte mails, 3 megabyte web pages, etc.) through at least one of these machines, and don't seem to have any problems playing streaming video or audio through the network, it's just the MS filesharing machine to machine that seems to screw up.

[Greenstead]

What are the model numbers of the router and cards?

There should be a linksys configuration utility which may display the driver and firmware versions for the cards. The router should tell you its firmware in its web configurator.

btw Are you using XP to automatically configure the wireless cards - do. Also disable power save on wireless cards. If you are using the linksys utility on XP try disabling it. Then try transfers.

It might be useful to watch the transfer on-going. Get the Analogx Netstat utility and watch the transfer.

(btw - I don't know the answer - just poking around for clues).

[wamontgomery]

[QUOTE]Originally posted by Greenstead
[B]What are the model numbers of the router and cards?

The router is BEFW11S4 (The original one), and the cards are

WPC11v3, (on a laptop running Windows ME)
and WUSB11v.26 (on a desktop running Windows XP)

There should be a linksys configuration utility which may display the driver and firmware versions for the cards. The router should tell you its firmware in its web configurator.

These seem to match the versions on the latest download, though the XP machine makes this hard to figure out. (The driver data you bring up on the device manager is old, but if you look at the details it gives you the version that matches the download)

btw Are you using XP to automatically configure the wireless cards - do. Also disable power save on wireless cards. If you are using the linksys utility on XP try disabling it. Then try transfers.

I don't use it on the XP system, just XP's stuff. I do use it on the ME system. In fact this is a bit of a pain. Since updating the software I discover that I have to run the utility and unlike the earlier one I had for the 3rd machine (which has a WPC11v1) it won't come up minimized. Yuck.

It might be useful to watch the transfer on-going. Get the Analogx Netstat utility and watch the transfer.

Did this, thanks for the pointer, it's a better tool than the built in performance tools on these machines (less cluttered at least). What I see in general matches what I said before though -- periods of steady activity with breaks of a few seconds of nothing. Actually my one attempt to transfer a big file worked, naturally, but did show the stoppages. One really interesting thing that I don't know what to make of -- Netstat on the ME machine showed a rate of about 180KB/sec out, while Netstat on the XP machine showed about 360KB/sec in AND 180KB/sec out. The only hint I have as to why is that when I poked around with the microsoft performance tool it showed an MS TCP Loopback driver that nothing else showed. Can there be some goofy loopback on this machine that it's picking up? I don't have any firewalls on the XP machine, but I do have ZoneAlarm on the ME machine. (I've tried running this without Zone alarm -- same results). The advanced properties for TCP show settings for TCP Filtering, all disabled.

(btw - I don't know the answer - just poking around for clues).

Thanks for trying to help. A fresh perspective is often useful even if you don't have the answers.

[Greenstead]

OK - interesting.

Some comments:

- the loopback driver is used for testing the local connection. It is not a concern I believe.

- You have to use the utility on pre-XP windows. On XP M$ say it may interfere and should be disabled.

- When observing Netsat be wary not to confuse KB (bytes) and Kb (bits). There will be a return flow of acks which should be in the Kbits level. (I think you configure Netstat to show either Bytes or Bits).

- If your observation of Netsat is accurate then of course there should not be the same flow back as the flow from the source. I was wondering - back in the good old DOS days when you did a file transfer there was a verify switch which read back what had been written - it almost sounds like that is happening - it should not be. Maybe the ME PC has a system setting to require verification of all copies - I dunno - I don't have ME. A verification would certainly disrupt the flow, especially bearing in mind that wireless comms is half duplex, not full - you probably would not notice on a fast wired FD connection.

- What happens when you transfer XP to ME. (It may also depend on if you push or pull the transfer - i.e. which PC you initiate the copy from).

- If its any consolation I also see the bursty type flow when I copy between wireless PCs (though I don't get transfer failures). I don't know why. It is quite different for internet downloads which pour down at a steady max flow. I guess its to do with TCP versus UDP methods - I dunno.

- It would be interesting to try a TFTP transfer between the PCs. (TFTP is Trivial FTP which uses UDP and does no packet acknowledgement so should flow as fast as possible - of course errors are undetected). I don't know how to try this offhand.

- Another interesting (free) utility is Qcheck which will do throput tests for you.
http://www.netiq.com/qcheck/default.asp

- It is probably worthwhile to reset TCP/IP. Uninstall and reinstall on the ME PC. You can't do that on XP - reset by this:
http://support.microsoft.com/default.aspx?scid=kb;en-us;299357



As you can see, I am in the guessing zone and exposing my lack of real knowledge. In my experience wireless is great for internet browsing and downloads, but aweful for LAN comms. It would be interesting to solve this.