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Hi

I have a Wireless capture between a client (Phone used for banking) and an AP. What i see from this cap is that when the client first associates to the AP (as always) it goes to PSP mode and then sends PS-Poll every 4th or 5th Beacon. Fair enough...

After the client is reset, not a proper disconnect but removing the clients battery etc. The client assoicates again and as always goes to PSP mode. but this tym sends PS-Poll every 8th or 9th Beacon.

My question is, What persuades the client to send PS-Poll (other than the TIM bit in the beacon) ... am quite confused over this functionality ...

Pls help!!

If the TIM doesn't list the AID of the STA, then there's no need for the STA to poll the AP. So, the amount of downstream traffic is what drives the number of uplink PS-POLL frames. Use a protocol analyzer to monitor downlink traffic to the phone (either on the wire or wirelessly with an analyzer that can decode the TIM virtual bitmap) in both cases (before and after). That should dispell the mystery.

Hope this helps.

Devinator

Hi Devin,

Thanks for the inputs ... the issue was found to be client behavior. Before resetting the client everything works fine. After reset client wakes only after the DTIM expires and hence causing the delay ...

Thanks for your help.