Re: Fixed DWL900AP frame captures

From: Jouni Malinen (
Date: 2002-09-21 12:55:10 UTC

On Thu, Sep 19, 2002 at 06:20:59PM -0400, Jason Boxman wrote:

> eth0 -- DWL900AP (AP mode) ~~ DWL900AP (Client AP mode) -- Laptop

Interesting.. Client AP mode uses WDS frames, but this time there were no frames with broadcast RA. In addition, WDS frames seems to be used only when needed (i.e., when the frame has two non-local addresses).

This mode looks "better" from the viewpoint of the Host AP driver and Prism2 firmware. Standard compliant WDS frames can be sent and received in Managed mode and I just added support for this kind of mode to the Host AP driver. I do not have DWL900AP, so I haven't tested this in real setup. However, I simulated the test and the driver was able to receive WDS frames from the AP and was able to send WDS frames that looked correct.

I would like to hear if anyone manages to test this with DWL900AP (or any other AP supporting such feature). Host AP driver should be set to Managed mode with AP client mode enabled:

iwconfig wlan0 mode Managed
prism2_param wlan0 wds_type 2

The card should then associate to an AP and one should be able to setup Linux bridge code to bridge packets between wired and wireless interface (example brctl commands for Master mode should be fine also for this). When incoming frames have local hwaddr as the destination or outgoing frames have local hwaddr as the source, the driver uses 3-addr FromDS and ToDS frames (this is the method normally used in Managed mode). If these addresses are non-local (e.g., device behind other bridge port), 4-addr WDS frame (FromDS + ToDS, IEEE 802.11 standard compliant) is used.


The capture with PtMP AP did not show any broadcast frames and I did not notice any difference to PtP mode.  

Jouni Malinen                                            PGP id EFC895FA

This archive was generated by hypermail 2.1.4.