From: Michael Wu <flamingice@sourmilk.net>
To: Johannes Berg <johannes@sipsolutions.net>
Subject: Re: [PATCH 0/4] Try #5: Radiotap on Monitor Mode interfaces for rx and tx
Date: Thu, 22 Mar 2007 19:10:30 -0400
Cc: andy@warmcat.com, linux-wireless@vger.kernel.org
References: <20070320103955.600509703@warmcat.com> <1174502809.3944.36.camel@johannes.berg>
In-Reply-To: <1174502809.3944.36.camel@johannes.berg>
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On Wednesday 21 March 2007 14:46, Johannes Berg wrote:
> If the driver does not support radiotap, ieee80211_rx_monitor needs to
> expand the head for each packet. Currently, this is also true, but since
> currently no non-management frames are sent down the management
> interface, this is not an issue. If each data packet needs to be first
> reallocated though, it quickly becomes a problem for low-power embedded
> access points running hostapd.
>
That's why drivers should be modified to support radiotap.

> Additionally, the overhead of tacking on radiotap headers to each
> received frame is also rather high if you're only interested in
> receiving the information for management frames.
>
It's really not that much overhead.

-Michael Wu

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