That's a good question. Let me tell you what I think I know -- that is to to say, what I have actually experienced -- with a few surmises thrown in.
I have had participated in several threads with people here and elsewhere in which this and similar behaviors were discussed. It appears that there are at least two fairly common issues which can lead to periodic disconnection of 802.1b wireless clients running under Windows XP. One of the issues seems to cause sporadic failure of the connection and periodic dips in network throughput during file transfers. That issue seems to be caused by poor firmware and / or driver design, and, so far, I've only seen users of the Linksys wireless clients complain of that behavior, though I'm certain others may experience it, too. Ostensibly, a fix for the Linksys firmware is due Real Soon Now (TM). The other issue appears to have cropped up with SP1 for Windows XP, and it seems to cause regular periodic disconnection with an announcement that there are wireless networks available (which means, of course, that you've been disconnected from the network to which you had been connected). The 802.1x authentication for wireless networks is enabled by default, but it doesn't apply to people with consumer-grade SOHO wireless routers like most of us use at home. These routers have no ability to use certificates, of course. In Windows XP prior to application of SP1 (or perhaps a combination of SP1 plus one of the subsequent security updates) leaving the 802.1x authentication feature enabled didn't seem to adversely affect the ability of wireless clients to use wireless routers in a reliable fashion for access to the Internet. Nevertheless, I had turned authentication off on my own machines because it appeared that it interfered with their ability to get access to shares on the LAN. Then I started noticing some problems in maintaining wireless connections following application of SP1, but they were tolerable. Then after I applied one of the recent security patches for IE I saw wireless connections become really unreliable -- dropping every couple of minutes or so. Because of the behavior (with the client manager announcing the presence of wireless networks) I figured that it was the Wireless Zero Configuration Service that was causing the problem. I learned that disabling Wireless Zero Configuration after getting a connection enabled me to hold that connection trouble-free for as long as I wanted. In the course of discussing this issue with others online someone reminded me that SP1 had tightened down the authentication behavior for wireless clients. I went to the authentication setting and, sure enough, found that it had been re-enabled -- apparently when I applied either SP1 or a subsequent patch. As soon as I turned off the authentication feature I found that all wireless connection functions returned to normal, and that it was no longer necessary to turn of the WZC service to maintain connections.
I don't think this exact behavior is actually intended by Microsoft, but I could be wrong. I hope someone who actually knows may be able to contribute some information. But I suspect that authentication is supposed to allow a wireless client to get to the Internet through a router even though it can't authenticate, and that authentication is supposed to be necessary only for acquiring access to shares on the network. My guess is that the periodic disconnection results from authentication continuing to look for a certificate server by having WZC look for "momma", but I could be dead wrong on that. However, if I'm wrong about this I'd like to know why turning the service off after getting a connection allows the client to maintain a wireless connection indefinitely.
Turning of the WZC Service appears to solve the wireless connection failure problem for people who have authentication turned on in the inappropriate setting (like the vast majority of home networks) and for many people who have problem drivers that aren't truly compatible with Windows XP and Wireless Zero Configuration. But, obviously, the better solution is either to turn off authentication or to get a better driver / firmware for the client, whichever applies to the given situation.
I hope you'll give this a shot and let us know how it turns out by post back to this thread.
Good luck!
- prosaic
