From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cesar Date: Tue, 28 Jun 2016 11:55:14 +0800 (CST) Subject: [ath9k-devel] ath9k monitor mode injection packet delay Message-ID: <6e91ed7f.6af3.15595258d46.Coremail.caesargo@163.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org Hello all, We?ve recently tried to test packet injection performace in ath9k monitor mode. We set 2 laptops in monitor mode , PC 1 send a 500 Byte packets out, and PC 2 return a 500 Bytes packet back at once when it receives the packet of PC 1. Then we measured the RTT time and found it's about 1000us !!! Test environment: NIC: AR9287 driver: ath9k system: ubuntu 14.04 with kernel 3.14.57 send rate : at a fixed rate 54Mb We tried to send packets as "low" as possible in driver stack, and we're sure that we disabled the CCA and backoff using flags below: AR_DIAG_FORCE_CH_IDLE_HIGH AR_DIAG_IGNORE_VIRT_CS AR_D_GBL_IFS_MISC_IGNORE_BACKOFF besides we change the aifs to 1 and cwmin cwmax to 0 in ath_txq_setup to ensure there's no backoff. we even put our laptaps to a underground garage where channel is almost clean.But the test results is still about 1000us.... We've been stucked for serveral months, Any suggestion? Any feedback welcome... Thnkz in advance!!! Cesar -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20160628/191bdc9e/attachment.htm