On 09 Aug 2014, at 22:22, hiren panchasara <hiren.panchas...@gmail.com> wrote:
> On Sat, Aug 9, 2014 at 12:51 PM, Michael Tuexen > <michael.tue...@lurchi.franken.de> wrote: >> >> On 09 Aug 2014, at 20:42, John-Mark Gurney <j...@funkthat.com> wrote: >> >>> Niu Zhixiong wrote this message on Fri, Aug 08, 2014 at 20:34 +0800: >>>> Dear all, >>>> >>>> Last month, I send problems related to FTP/TCP in a high RTT environment. >>>> After that, I setup a simulation environment(Dummynet) to test TCP and SCTP >>>> in high delay environment. After finishing the test, I can see TCP is >>>> always slower than SCTP. But, I think it is not possible. (Plz see the >>>> figure in the attachment). When the delay is 200ms(means RTT=400ms). >>>> Besides, the TCP is extremely slow. >>>> >>>> ALL BW=20Mbps, DELAY= 0 ~ 200MS, Packet LOSS = 0 (by dummynet) >>>> >>>> This is my parameters: >>>> FreeBSD vfreetest0 10.0-RELEASE FreeBSD 10.0-RELEASE #0: Thu Aug 7 >>>> 11:04:15 HKT 2014 >>>> >>>> sysctl net.inet.tcp >>> >>> [...] >>> >>>> net.inet.tcp.recvbuf_auto: 0 >>> >>> [...] >>> >>>> net.inet.tcp.sendbuf_auto: 0 >>> >>> Try enabling this... This should allow the buffer to grow large enough >>> to deal w/ the higher latency... >>> >>> Also, make sure your program isn't setting the recv buffer size as that >>> will disable the auto growing... >> I think the program sets the buffer to 2MB, which it also does for SCTP. >> So having both statically at the same size makes sense for the comparison. >> I remember that there was a bug in the combination of LRO and delayed ACK, >> which was fixed, but I don't remember it was fixed before 10.0... > > If you are thinking of r256920, I believe it did make it into 10.0R. Yepp, that is what I was thinking of... Best regards Michael > > cheers, > Hiren > _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
