I have confirmed that there is no problem with settings of Dummynet. When Host-A/B uses Linux, the throughput of RTT=20ms (using Iperf) is same as that of RTT=0ms.
Host-A/B use FreeBSD v6.0 release. Does anyone have experience/suggestion for achieving high throughput with FreeBSD? Michael Vince wrote: > Zongsheng Zhang wrote: > >> Hi, *, >> >> For testing throughput of a TCP connection, the following topology is >> used: >> Host-A ---GB Ethernet--- Dummynet ---GB Ethernet--- Host-B >> >> Host-A/B use FreeBSD v6.0. Sysctl parameters of Host-A/B are: >> kern.ipc.nmbclusters=32768 >> net.inet.tcp.inflight.enable=0 >> net.inet.tcp.sendspace=2097152 # 2M >> net.inet.tcp.recvspace=2097152 # 2M >> >> When RTT in Dummynet is set to 0ms, the throughput (A--B) is about >> 900Mbps. The buffer size is enough to fill a link bandwidth=800Mbps, and >> RTT=20ms. However, if RTT is set to 20ms, the throughput is only about >> 500Mbps. >> >> Are there other parameters which are necessary to adjust? Does anyone >> have suggestion for high throughput? >> >> Thanks in advance. >> >> >> > What are you following on your hosts? Release/stable or current? I only > use just release or stable. > > For your middle router try net.inet.ip.fastforwarding or net.isr.direct > but not at the same time, then try on top enabling polling. > Personally I found enabling polling worked best combined with > net.inet.ip.fastforwarding. > > Andre Oppermann claimed in a post just recently he gets best performance > using just net.inet.ip.fastforwarding without polling but that might be > for just -current, I am not sure. > > You could also try using current, but if I had to guess you already are? > > Regards, > Mike > > -- Zongsheng Zhang [EMAIL PROTECTED] _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
