Re: ath client bridge

On Oct 20, 2005, at 3:24 AM, Jim Thompson wrote:

 >     1                0          DA      BSSID       SA        X

more importantly, when a device "behind" the AP sends a packet for  
and SA that is behind your "client bridge", how does the AP know  
where to send the frame on the wireless medium?

Or, in this case:
 >     0                1        BSSID     SA          DA        X

When a device "behind" your client bridge sends a frame through your  
client bridge, and "SA" is this "device behind", how can the AP  
possibly accept the frame.  It doesn't (appear) to come from an  
associated STA (SA isn't the address for the device that sent the  
packet), and the AP certainly can't ACK the frame, (so why would it  
forward it?)

This is why the "4 address" frame type (with FromDS and ToDS both  
set) exists.

      1                1          RA          TA          DA      SA

RA = device on wireless media "receiving" the frame
TA = device on the wireless media "transmitting the frame"
SA = original source of the packet
DA = original (and ultimate) destination of the packet

jim