Wireless connection drop with large files and thumbnail view.

[shawndavis]

I just installed 2 D-Link DWL-G520 NICs in two different machines, which are connected via ad-hoc mode. My server is running 2000 Server, and the other machine is XP MCE. I've got ISA server doing the routing, and all is well with internet connectivity and downloading. I tested this by downloading a 100Meg file from Microsoft, I was averaging ~280Kbps.

The only problem I'm having, is with large file transfers and any file which has a thumbnail (pictures for example). I don't even have to initiate the transfer (cut/copy and paste) to lose connection. Basically, if I browse in explorer, to a directory which contains pictures or large movie files, there is a ton of tx and rx activity between the two machines, and I will lose connection. This happens continually for about 3.5 minutes; I lose connection for about 2 or 3 seconds, and then it will come back for anywhere from 2 to 10 seconds, and drop again. After about 3.5 minutes, the tx and rx will esentially stop completely, and I'll have a solid constant connection. The whole time (even when the link status reports "No Connection to Network&quot, my signal strentgh reports as excelent, and the speed reports as 54Mbps.

At first I thought I'd be ok if I just disable thumbnail view, and set up explorer to list files as icons instead. This clears up the problem of browsing into the directory containing all of the pictures or video files, but as soon as I click on, or hover over one of the files, the tx and rx spike again. If I wait a couple minutes for the tx / rx to to settle down, and copy / paste the file across the network, the connection starts dropping like crazy again. To transfer a 600Meg file, explorer reports that it will take ~90 minutes. If I cancel the copy, I regain my solid connection. I have tried installing the Windows XP wireless rollout update, and I've also tried disabling the the wireless zero configuration both with no change in the problem. I am not using encryption, and and I have my signal speed and channel setup to auto. I've also tried defining all channels, and speed settings. I apologize for the huge post, I just wanted to make sure I gave all the information I can think of. Does anyone have any suggestions, or is anyone else having this same problem. Also, I have the lastest drivers, and have tried adjusting the preamble on the NICs. Should I return the cards and purchase a different brand? Any help is greatly appreciated.

 

[bcastner]

Occasionally you won't be able to delete or even move an AVI file, because as soon as you click on the file, Explorer hangs while trying to offer a preview of it. This usually happens when the AVI file is incomplete or corrupt. A quick Registry fix will unlock your AVIs so you can move or delete them.

Click on Start | Run; now type Regedit and click on OK. Browse to HKEY_CLASSES_ROOT\System FileAssociations\.avi\shellex\PropertyHandler and delete the Default key contained in this folder.

2. This works too to resolve the issue:

http://w3.uqo.ca/durp01/en/avifixp/news.html

 

[shawndavis]

Thanks for the reply bcastner. The only thing is, I'm not trying to open or delete these files, I just open the directory, and this happens. Also, this isn't just media files, it's really anything over 3 megs that I notice the problems, plus the files aren't corrupt. The larger the file, the longer it takes for the connection to stablize. I figured it had something to do with the auto preview, which is why I set my view to icons only, but that doesn't correct my problem of transfering the files. Even still, should auto preview of an icon wipe out my net connection. All other machines are connected via wire, and they have no problems at all. This machine was on wire previously, but I finally got 2 802.11g NICs, to get rid of the cable running from my den out to my back yard, and into the living room. Thanks again for the help.

 

[bcastner]

The issue to me is that Explorer can stop responding, even in the absence of any notice, and in the absence of a copy operation. It can spend nearly forever reading to the end of a video file to read the header/property information for the file (which is stored at the end). When it stops responding your connection appears as if disconnected.

One other common item for this problem is either the lack of a suitable codec, or a bad codec.

 

[shawndavis]

Thank you again, but it's not just media files. I have the most information based on media files, because that is the main thing I need to transfer to the PC in my living room. I have tried .zip files, .rar files, .iso files, everything. It's not the files that are causing this, it's something else. If I copy a file that is ~2 megs or less I'm ok, it's as though there isn't enough time for the connection to drop. Anything above 2 meg has time to drop, and boy does it drop.

 

[jmbuis]

****** sorry, long post - but major issue ******


Shawn

I am sorry I am not providing any solution but my experience brings further information.

I experience the same kind of issue with my wireless lan i.e. whenever large files are transferred or rather a file transfer with a long connection is required, the connection is lost at a random point in time. Most times the wireless lan is then crippled (I will elaborate below)

My wireless hardware consists of the following :
1 Netgear Router WGR 614 Firmware 1.1.26
1 Netgear Cardbus WG 511 Driver 1.6
1 Netgear PCI WG 311

All computers
- run XP Home or XP Pro
- do *not* use XP wireless network management

The wireless lan does not use encryption.

With this setup, when the connection is lost, the only way to restore the wireless lan is to reset the router. However, I know that the wired lan from the router still works (I tried)

Now for other various tests :

(1) I have tried transfers on the same wireless lan between my desktop running XP Pro and a laptop running Win 2K Pro, the same problem arises BUT the wireless lan recovers, it is just Windows' file sharing which is down (e.g. I can still browse the internet)

(2) I have tried replacing the Netgear wireless connectivity with a Linksys adsl router, the same issue arises

(3) I have tried replacing the Netgear WG-511 pcmcia adapter with a Linksys 802.11g pcmcia adapter, the same issue arises

MY CONCLUSIONS :

* the issue is not - only - brand dependant. At least, it is an issue with both Netgear and Linksys hardware, on both the AP and adapter side

* the issue is somehow OS dependant, the behaviour with Win XP and Win 2k being significantly different

 

[bcastner]

I vote with jmbuis that it is an OS issue. As a first cut, take some clues from the pure server side and resolve SMB signing and opportunistic locking issues on the clients. This MS KB article is a kind of catchall for client-server issues, and I would apply all of the SMB and op lock workarounds suggested:

http://support.microsoft.com/default.aspx?scid=kb;en-us;814112

 

[shawndavis]

Yeah, I gave up after a couple weeks of racking my brain and trying to find the problem using ethereal to snoop the traffic. I dilled two holes in my house, dug a small trench in the backyard, and ran a cable through some pvc pipe into my living room. It was a lot more work of course, but saved me any future head aches and about $140, not to mention the fact that it's 100Mbps and not 28Mbps if I was lucky. Good luck to you though, I hope find a solution.

 

[bcastner]

http://support.microsoft.com/default.aspx?scid=kb;en-us;821400

If XP, be certain you apply the new wireless rollup hotfix package:

http://support.microsoft.com/?kbid=826942

 

[bcastner]

I note that using a different client can resolve these problems.

I particularly like Funk Software's Odyssey client, a free trial download is available:

http://www.funk.com/radius/wlan/wlan_radius.asp

 

[fugitivepope]

Shawn and jmbuis:

I'm experiencing the exact situation as described by both of you using a D-Link 614+ wireless router. One of my tests was with a 2 mb text file using three different browsers on a Windows XP Professional box which caused the same temporary lockup.

I'm going to install the XP wireless roll-up as suggested. Shawn, have you done that and fixed the problem? I'll chime in if it fixes mine.

Other tests: is this just a browser issue or throughput in general? I get the exact behavior whether I use Mozilla or MSIE. Will try ftp and see if the same things happen (I predict it will).

More fodder: I also have a Windows XP (Home) box that exhibited the EXACT behavior with a direct DSL connection telling me that there definitely is an issue with hardware, drivers, OS, etc. (as usual). When I hook up with my crappiest Win98 box, everything works fine telling me that the DSL connection isn't directly the issue.

If I can get stuff working I'll chime in here.

 

[shawndavis]

I installed thewireless package when I was still troubleshooting, but have since given up on wireless. When you test FTP transfers, if your problem is indeed the same as mine, FTP will transfer fine, no drops at all. Good luck buddy.