Here's a real stumper for you. An IBM thinkpad connects beautifully to a Belkin F5D7230-4 (2000) UNTIL you pull the laptop's power plug out of an outlet. Then, the connection is lost.
And, it's not the laptop. Connects to Starbucks T-Mobile hotspot fine
-- and stays connected even after pulling the plug. Same story with a friend's netgear. So, it's the Belkin router.
Any suggestions?
Well, the card is part of the computer and is controlled by the computer and is not the router. If the computer had a connection before the computer went on the battery, then how does the router have a problem?
That's what makes it a stumper. I have not been able to duplicate the error using either a netgear router (with the exact WEP) nor at the t-mobile network at starbucks. Makes me think it's not the laptop - otherwise it would have the problem with any router.
W> snipped-for-privacy@gmail.com wrote:
How does the router know that the laptop went on a battery and it did something at that point to stop transmitting to the card? It doesn't.
Did the laptop loose the IP, and is still connected to the router, but it doesn't have an IP being used on the router, therefore, it can't access the Internet?
Did you issue an IPconfig /all at the DOS Command prompt to see what IP(s) the machine has when it's on the wall plug, as opposed to it being on the battery?
Have you tried IPconfig /release and IPconfig /renew when the connection is lost when you switch to battery power.
Have you booted the machine on battery power and can it access the Internet at that point?
Have you had anyone come to your place with a laptop to see if the problem follows?
Perhaps the wireless goes into some power-saving mode that the AP doesn't support. Check the AP configs to see if there are any power-saving features that need to be enabled.
Jerry
Check the router's DTIM interval setting.
snipped-for-privacy@newsguy.com (Neill Massello) hath wroth:
Good idea except for one problem. The DTIM (Delivery Traffic Indication Message) only works when the wireless client is in power save mode. It's unlikely that the client would be in power save mode with one access point, but not another.
A typical default DTIM interval of 1 means that data will be sent immediately after every beacon frame. A DTIM interval of 3 means that data will be sent after every 3 beacon frames. Basically, it tell the client that there are some number of data packets to follow and that the client can go to sleep while the packets are being sent (unless they're destined for a particular client in which case the client stays awake). Since the default beacon rate is 10 beacons per second, it's highly unlikely that a client will disconnect because it missed a beacon frame.
Some notes on power save mode:
DTIM also has a big effect on thruput, especially when using multicast.
An access point buffers all multicast frames and sends them immediately following the next DTIM (delivery traffic indication message) if any one client associated with the access point enables power saving mode. When all stations have power saving off, then the access point transmits a multicast frame as soon as possible and doesn't wait for the next DTIM. Note that power save mode has to be off for this to work.
I have no idea what's actually happening with the Belkin router, but I do agree that there's probably something amis with the router. Check if the power save mode is enabled on the wireless card properties. If so, turn it off and see if it helps.
But what if the client card is in power-saving mode with all three APs but only the Belkin's high DTIM setting is somehow incompatible with the ThinkPad's card (or firmware or driver)? I took the OP to be implying that this problem only arose between one AP and one client on battery power, although he didn't specify whether any other clients had the same problem with the same AP.
snipped-for-privacy@newsguy.com (Neill Massello) hath wroth:
Well, one out of 3 access points is good enough to point to the Belkin as the probable culprit. My comments were in reference to the DTIM interval. The only way I would guess(tm) it could generate a disconnect is if the DTIM interval was set to a fairly large number to improve performance and the unspecified model IBM laptop client missed a few management frames for some reason. It's probably an older model or the OP would have said it was a Lenovo laptop. Reading the original description, it seems that the disconnect was instantaneous upon removing the AC adapter.
Most IBM Thinkpads use Intel MiniPCI cards with Intel Proset drivers and IBM ThinkVantage client. The Proset 9.x drivers were marginal.
10.x work quite nicely. There are plenty of options in the wireless card advanced properties that could easily screw things up. Methinks (not sure) 10.x has a "reset to defaults" button. 10.x does have a wireless troublshooter which enables event logging.ThinkVantage and drivers:
Proset:
It's an IBM ThinkPad model T40.
Jeff Liebermann wrote:
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