Date: Sat, 9 Aug 2014 09:51:49 +0000 From: "Eggert, Lars" <lars@netapp.com> To: Niu Zhixiong <kaiaixi@gmail.com> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, Bill Yuan <bycn82@gmail.com> Subject: Re: A problem on TCP in High RTT Environment. Message-ID: <A6B17C10-F72F-4182-9A1C-FD787448E068@netapp.com> In-Reply-To: <CAOENNMA_CiBDJc0kchzUbTcf_JBwTJPF=PdBAUB6FPo-KzYkeQ@mail.gmail.com> References: <CAOENNMA_CiBDJc0kchzUbTcf_JBwTJPF=PdBAUB6FPo-KzYkeQ@mail.gmail.com>
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--Apple-Mail=_F3479225-B71E-45E7-9BAC-EAF4DAEF047F Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 At 400ms at @ 20Mbps, your are probably receive window limited. Bump = net.inet.tcp.recvspace. (Your net.inet.sctp.recvspace is much larger, = which probably explains the performance difference.) On 2014-8-8, at 14:34, Niu Zhixiong <kaiaixi@gmail.com> wrote: > Dear all, >=20 > 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=3D400ms). > Besides, the TCP is extremely slow. >=20 > ALL BW=3D20Mbps, DELAY=3D 0 ~ 200MS, Packet LOSS =3D 0 (by dummynet) >=20 > This is my parameters: > FreeBSD vfreetest0 10.0-RELEASE FreeBSD 10.0-RELEASE #0: Thu Aug 7 > 11:04:15 HKT 2014 >=20 > sysctl net.inet.tcp > net.inet.tcp.rfc1323: 1 > net.inet.tcp.mssdflt: 536 > net.inet.tcp.keepidle: 7200000 > net.inet.tcp.keepintvl: 75000 > net.inet.tcp.sendspace: 32768 > net.inet.tcp.recvspace: 65536 > net.inet.tcp.keepinit: 75000 > net.inet.tcp.delacktime: 100 > net.inet.tcp.v6mssdflt: 1220 > net.inet.tcp.cc.algorithm: newreno > net.inet.tcp.cc.available: newreno > net.inet.tcp.hostcache.cachelimit: 15360 > net.inet.tcp.hostcache.hashsize: 512 > net.inet.tcp.hostcache.bucketlimit: 30 > net.inet.tcp.hostcache.count: 0 > net.inet.tcp.hostcache.expire: 3600 > net.inet.tcp.hostcache.prune: 300 > net.inet.tcp.hostcache.purge: 0 > net.inet.tcp.log_in_vain: 0 > net.inet.tcp.blackhole: 0 > net.inet.tcp.delayed_ack: 1 > net.inet.tcp.drop_synfin: 0 > net.inet.tcp.rfc3042: 1 > net.inet.tcp.rfc3390: 1 > net.inet.tcp.experimental.initcwnd10: 1 > net.inet.tcp.rfc3465: 1 > net.inet.tcp.abc_l_var: 2 > net.inet.tcp.ecn.enable: 0 > net.inet.tcp.ecn.maxretries: 1 > net.inet.tcp.insecure_rst: 0 > net.inet.tcp.recvbuf_auto: 0 > net.inet.tcp.recvbuf_inc: 16384 > net.inet.tcp.recvbuf_max: 2097152 > net.inet.tcp.path_mtu_discovery: 1 > net.inet.tcp.tso: 1 > net.inet.tcp.sendbuf_auto: 0 > net.inet.tcp.sendbuf_inc: 8192 > net.inet.tcp.sendbuf_max: 2097152 > net.inet.tcp.reass.maxsegments: 15900 > net.inet.tcp.reass.cursegments: 0 > net.inet.tcp.reass.overflows: 0 > net.inet.tcp.sack.enable: 1 > net.inet.tcp.sack.maxholes: 128 > net.inet.tcp.sack.globalmaxholes: 65536 > net.inet.tcp.sack.globalholes: 0 > net.inet.tcp.minmss: 216 > net.inet.tcp.log_debug: 0 > net.inet.tcp.tcbhashsize: 32768 > net.inet.tcp.do_tcpdrain: 1 > net.inet.tcp.pcbcount: 4 > net.inet.tcp.icmp_may_rst: 1 > net.inet.tcp.isn_reseed_interval: 0 > net.inet.tcp.soreceive_stream: 0 > net.inet.tcp.syncookies: 1 > net.inet.tcp.syncookies_only: 0 > net.inet.tcp.syncache.bucketlimit: 30 > net.inet.tcp.syncache.cachelimit: 15375 > net.inet.tcp.syncache.count: 0 > net.inet.tcp.syncache.hashsize: 512 > net.inet.tcp.syncache.rexmtlimit: 3 > net.inet.tcp.syncache.rst_on_sock_fail: 1 > net.inet.tcp.msl: 30000 > net.inet.tcp.rexmit_min: 30 > net.inet.tcp.rexmit_slop: 200 > net.inet.tcp.always_keepalive: 1 > net.inet.tcp.fast_finwait2_recycle: 0 > net.inet.tcp.finwait2_timeout: 60000 > net.inet.tcp.keepcnt: 8 > net.inet.tcp.rexmit_drop_options: 0 > net.inet.tcp.per_cpu_timers: 0 > net.inet.tcp.timer_race: 0 > net.inet.tcp.maxtcptw: 26070 > net.inet.tcp.nolocaltimewait: 0 >=20 > kern.ipc.maxsockbuf: 4000000 > kern.ipc.sockbuf_waste_factor: 8 > kern.ipc.max_linkhdr: 16 > kern.ipc.max_protohdr: 60 > kern.ipc.max_hdr: 76 > kern.ipc.max_datalen: 92 > kern.ipc.maxmbufmem: 2073962496 > kern.ipc.nmbclusters: 253170 > kern.ipc.nmbjumbop: 126584 > kern.ipc.nmbjumbo9: 112518 > kern.ipc.nmbjumbo16: 84388 > kern.ipc.nmbufs: 1620285 > kern.ipc.maxpipekva: 66736128 > kern.ipc.pipekva: 16384 > kern.ipc.pipefragretry: 0 > kern.ipc.pipeallocfail: 0 > kern.ipc.piperesizefail: 0 > kern.ipc.piperesizeallowed: 1 > kern.ipc.msgmax: 16384 > kern.ipc.msgmni: 40 > kern.ipc.msgmnb: 2048 > kern.ipc.msgtql: 40 > kern.ipc.msgssz: 8 > kern.ipc.msgseg: 2048 > kern.ipc.semmni: 50 > kern.ipc.semmns: 340 > kern.ipc.semmnu: 150 > kern.ipc.semmsl: 340 > kern.ipc.semopm: 100 > kern.ipc.semume: 50 > kern.ipc.semusz: 632 > kern.ipc.semvmx: 32767 > kern.ipc.semaem: 16384 > kern.ipc.shmmax: 536870912 > kern.ipc.shmmin: 1 > kern.ipc.shmmni: 192 > kern.ipc.shmseg: 128 > kern.ipc.shmall: 131072 > kern.ipc.shm_use_phys: 0 > kern.ipc.shm_allow_removed: 0 > kern.ipc.soacceptqueue: 128 > kern.ipc.numopensockets: 14 > kern.ipc.maxsockets: 130350 > kern.ipc.sendfile.readahead: 1 >=20 > sysctl net.inet.sctp > net.inet.sctp.sendspace: 2097152 > net.inet.sctp.recvspace: 2097152 > net.inet.sctp.auto_asconf: 1 > net.inet.sctp.ecn_enable: 1 > net.inet.sctp.strict_sacks: 1 > net.inet.sctp.peer_chkoh: 256 > net.inet.sctp.maxburst: 4 > net.inet.sctp.fr_maxburst: 4 > net.inet.sctp.maxchunks: 31646 > net.inet.sctp.tcbhashsize: 1024 > net.inet.sctp.pcbhashsize: 256 > net.inet.sctp.min_split_point: 2904 > net.inet.sctp.chunkscale: 10 > net.inet.sctp.delayed_sack_time: 200 > net.inet.sctp.sack_freq: 2 > net.inet.sctp.sys_resource: 1000 > net.inet.sctp.asoc_resource: 10 > net.inet.sctp.heartbeat_interval: 30000 > net.inet.sctp.pmtu_raise_time: 600 > net.inet.sctp.shutdown_guard_time: 180 > net.inet.sctp.secret_lifetime: 3600 > net.inet.sctp.rto_max: 60000 > net.inet.sctp.rto_min: 1000 > net.inet.sctp.rto_initial: 3000 > net.inet.sctp.init_rto_max: 60000 > net.inet.sctp.valid_cookie_life: 60000 > net.inet.sctp.init_rtx_max: 8 > net.inet.sctp.assoc_rtx_max: 10 > net.inet.sctp.path_rtx_max: 5 > net.inet.sctp.path_pf_threshold: 65535 > net.inet.sctp.add_more_on_output: 1452 > net.inet.sctp.incoming_streams: 2048 > net.inet.sctp.outgoing_streams: 10 > net.inet.sctp.cmt_on_off: 0 > net.inet.sctp.nr_sack_on_off: 0 > net.inet.sctp.cmt_use_dac: 0 > net.inet.sctp.cwnd_maxburst: 1 > net.inet.sctp.asconf_auth_nochk: 0 > net.inet.sctp.auth_disable: 0 > net.inet.sctp.nat_friendly: 1 > net.inet.sctp.abc_l_var: 2 > net.inet.sctp.max_chained_mbufs: 5 > net.inet.sctp.do_sctp_drain: 1 > net.inet.sctp.hb_max_burst: 4 > net.inet.sctp.abort_at_limit: 0 > net.inet.sctp.strict_data_order: 0 > net.inet.sctp.min_residual: 1452 > net.inet.sctp.max_retran_chunk: 30 > net.inet.sctp.log_level: 0 > net.inet.sctp.default_cc_module: 0 > net.inet.sctp.default_ss_module: 0 > net.inet.sctp.default_frag_interleave: 1 > net.inet.sctp.mobility_base: 0 > net.inet.sctp.mobility_fasthandoff: 0 > net.inet.sctp.udp_tunneling_port: 0 > net.inet.sctp.enable_sack_immediately: 0 > net.inet.sctp.nat_friendly_init: 0 > net.inet.sctp.vtag_time_wait: 60 > net.inet.sctp.buffer_splitting: 0 > net.inet.sctp.initial_cwnd: 3 > net.inet.sctp.rttvar_bw: 4 > net.inet.sctp.rttvar_rtt: 5 > net.inet.sctp.rttvar_eqret: 0 > net.inet.sctp.rttvar_steady_step: 20 > net.inet.sctp.use_dcccecn: 1 > net.inet.sctp.blackhole: 0 > net.inet.sctp.debug: 0 >=20 >=20 > Regards, > Niu Zhixiong > =EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D= =EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D > kaiaixi@gmail.com > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" --Apple-Mail=_F3479225-B71E-45E7-9BAC-EAF4DAEF047F Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="signature.asc" Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Message signed with OpenPGP using GPGMail 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