From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ali Abedi Date: Tue, 23 Oct 2012 16:36:51 -0400 Subject: [ath9k-devel] Performance degradation when monitor interface is enabled In-Reply-To: References: <5086EA9A.6030400@mailservices.uwaterloo.ca> Message-ID: <5086FFE3.4010108@mailservices.uwaterloo.ca> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org Thanks Adrian. But there is no problem on the receiver side I assume (monitor mode is not enabled on the receiver). There are gaps between frames sent by the sender. It seems that the sender is waiting or doing something between frames (other than back-off, DIFS, ...) when the monitor mode is enabled on the sender. Ali On 10/23/2012 3:20 PM, Adrian Chadd wrote: > On 23 October 2012 12:06, Ali Abedi wrote: >> Hello, >> >> I asked this question once before but didn't get a satisfying answer. In >> our experiments, with two laptops running Ath9k driver we get about 29 >> Mbps bandwidth (802.11g configuration + UDP traffic), but when the >> monitor mode interface is enabled on the sender the throughput drops to >> 25 Mbps. This is not a performance issue. The performance is unaffected >> if monitor mode interface is enabled on the receiver (no monitor >> interface on sender). I really appropriate your answer. > Start by looking at what's different. The only real change monitor > mode makes int he driver is fondling the RX filter. > > It's possible that with monitor mode on, there's more stuff being > punted up to the driver on the receive side (all the other stuff in > the air) and that's causing things to slow down. > > > Adrian