I hace recently started to use the HIbernate option when closing down my XP SP2 PC. I did this for various reasons, quicker startup and shutdown for one. But I have noticed increased instability with my wireless connection after a startup from a hibernate shutdown. The wireless connection just keeps dropping out. That doesn't happen after a normal startup.
Has anyone else experienced this? Is it a known issue?
On 6 Feb 2007 03:07:49 -0800, "mercury" wrote in :
I have no such problems with the wireless in my ThinkPad T41, which works perfectly after resuming from hibernation. Your likely problem is your wireless driver. Get the latest version. If that doesn't help, try a different wireless adapter.
"mercury" hath wroth:
It seems to be a problem that's equally distributed between the access points and the clients. I have an HP ze2000 XP laptop with some Broadcom wireless card that recovers from hibernate just fine with my WRT54GSv4 (with DD-WRT) in both my home and office. However, the same laptop has to bludgeoned into cooperation (enable/disable, repair, etc) at some customers locations. I recently switched from the v3 to the v4 client drivers on the HP, and recovery was dramatically improved.
My guess(tm) is that the access points seem to think that they run things. That's the way 802.11 was written for infrastructure mode. When I client just disappears (during hibernation), the access point eventually flushes the MAC address table, clears the WPA encryption key register, and removes the SSID from the connection table. In other words, the client is history.
Then, the client magically re-appears as if nothing unusual has happened. The client assumes that the wireless connection is still active and proceeds from where it left off. Obviously, this isn't going to work and the access point is going to reject everything. At this point, a reasonably intelligent client will recognize the problem, and re-initiate the entire session starting with the probe request, encryption key exchange, DHCP request, etc. A stupid client will just continuously bang on the access point until the user does something to restart the connection. I've seen both.
I have the same problem with my PDAphone (Verizon XV6700). It has wi-fi which is really handy. However, the wi-fi section really eats battery power so various power saving features are used, including hibernate. Reconnnection is just as slow as an initial connection, which suggests that it's restarting the connection every time it comes out of hibernate. Brute force conquers all.
Eventually, we'll have 802.11r (fast roaming) which will allow for fast connects and disconnects for roaming between multiple access points. This should (hopefully) have the added beneficial side effect of also quickly restarting hibernate connections. Meanwhile, it appears to be a crap shoot.
On Tue, 06 Feb 2007 10:05:59 -0800, Jeff Liebermann wrote in :
Not if it's properly written. Windows notifies all drivers and applications (1) before hibernation and (2) during wakeup and reinitialization. The usual problem is third-party software that doesn't handle hibernation properly.
The Atheros mini PCI Wi-Fi card in my ThinkPad T41 using Windows XP WZC has no problem waking up from hibernation and properly reconnecting either to the last access point or to a new access point. It just works.
On Tue, 06 Feb 2007 18:46:00 GMT, John Navas wrote in :
I was wrong: I ran more careful tests with my ThinkPad, connecting to Wi-Fi network A, hibernating, and awakening to connect to Wi-Fi network B. I found that Windows WZC had retained DHCP settings from network A (gateway, etc.), which didn't work on network B. I had to "Repair" the connection to get the correct settings for network B from DHCP. This is indeed a bug, and I stand corrected.
Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.