Date: Mon, 21 Jun 2004 08:19:45 -0400 From: Long Le <le@unc.edu> To: freebsd-net@freebsd.org Subject: Blasting UDP packets on a 1-Gbps link Message-ID: <20040621121945.GB18534@quartet.cs.unc.edu>
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Hi all, I've been trying to get iperf to blast UDP packets for 10 minutes on a 1-Gbps link. However, iperf stops after a few seconds and complains that it can't write to the socket because no buffer space is available. 'netstat -m' shows that there are lots of mbufs available. I modified iperf source code to set the socket's send buffer to 200000 bytes (*) but it didn't really help much. In another attempt, I modified iperf source code such that it would not quit after failing to write to the socket. However, this caused iperf to hang. I use iperf 1.7.0 and FreeBSD 4.5. The machine I am using has a 1-GHz CPU and 1 Gbytes of memory. I could try to write my own program to blast UDP packets but would prefer to use available software if possible. Has anyone successfully blasted UDP packets on a 1-Gbps link for a sustained period and can anyone give me some useful hints? Thanks, Long (*) Apparently, iperf doesn't have an option to set the socket buffer for UDP sockets. And there seems to be a limit that doesn't allow to set a larger buffer size than around 200000 bytes (this is not related to iperf but FreeBSD in general).
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