From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailsrv0.aau.at ([143.205.180.48]:33807 "EHLO mailsrv.uni-klu.ac.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751963AbaFDG3Q (ORCPT ); Wed, 4 Jun 2014 02:29:16 -0400 Received: from mailsrv.uni-klu.ac.at (localhost [127.0.0.1]) by mailsrv.uni-klu.ac.at (Postfix) with ESMTP id D15C41608DC for ; Wed, 4 Jun 2014 08:23:03 +0200 (CEST) Received: from [192.168.0.103] (91-114-145-220.adsl.highway.telekom.at [91.114.145.220]) by mailsrv.uni-klu.ac.at (Postfix) with ESMTPSA id B62901608D8 for ; Wed, 4 Jun 2014 08:23:03 +0200 (CEST) Message-ID: <538EBB1C.3060106@aau.at> (sfid-20140604_082920_030895_697AA1E9) Date: Wed, 04 Jun 2014 08:22:20 +0200 From: Severin Kacianka MIME-Version: 1.0 To: linux-wireless@vger.kernel.org Subject: A question about monitor mode Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hello, I have a question about monitor mode and the monitor interface: When will a frame show up in the monitor interface? If I understand 802.11 correctly, there will first be a Request to Send (RTS), then a Clear to Send (CTS) signal. Then the actual frame will be send followed by an ACK. I did some testing and it seems, that the frame shows up in the monitoring interface after the ACK is received. My test setup was to record the socket.send call of an UDP packet with an unique ID and then measure the time it takes for that packet to be read on the monitor interface. As the measured time was not constant, but seemed to vary in relation to the network conditions I suppose that the frame only shows up after its delivery was acknowledged. Is this observation correct and where in the kernel's source (or elsewhere) should I look for more details? Thank you for your time and best regards, Severin