From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ed W Date: Tue, 16 Aug 2005 22:04:15 +0000 Subject: [LARTC] Packets being coallesced Message-Id: <430262DF.6000608@wildgooses.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Here's a peculiar one. I'm trying to simulate some speed effects due to varying sized packets so I have written a quick perl app which spits out packets of a fixed size (<1500 bytes). What I'm finding is the despite apparently turning off nagle and everything else I can think of I still notice that when the receiver isn't keeping up that the sending side (linux 2.6.11) is coalescing the packets and sending fewer large packets...? Is this a known and expected thing to do, or am I likely suffering some buffering effects in my perl app? Note: I am observing the effect based on tcpdump traces, so I can clearly see when it's sending the expect 1000 byte packets, and when it's suddenly packing them altogether into max MTU sized packets. Note also that it's *sending* them like this, it's not just the the receiver is buffering and receiving them like this... Seems odd to me? Ed W _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc