Holger Hoffstaette wrote:
On Sun, 17 Aug 2008 22:53:23 -0300, Norberto Bensa wrote
Ah!! But Windows (XP) uses TC by default. It doesn't use 20% of the
network bandwidth unless you tweak some registry setting and/or disable
QoS in network properties.
This is not the case. Please read:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q316666
The last paragraph could not be more clear on this.
Thanks... I was pretty sure that reserving a proportion of my LAN
bandwidth wouldn't help - though I didn't have that reference to hand.
I'd have been happy to rate-limit to 80mbps if that would have helped -
though I saw no reason that it should.
Much more likely is that the Gentoo (Linux) TCP Window sizing is more
aggressive and/or the Windows app/stack does not do the same. The OP
should ensure that window sizing is turned on (might be off) and bump up
the initial window size.
This sounds far more plausible to me... it certainly seems to be
something to do with the TCP stack on Gentoo.
I've had a look at http://gentoo-wiki.com/HOWTO_TCP_Tuning - which was
interesting - but didn't suggest any clear answers to me. From sysctl,
I discovered that tcp_congestion_control is "cubic" - which isn't even
an option documented by the wiki... I wonder, does the "C" in BIC mean
"cubic" - making these one and the same? The LWN article suggests not.
Is "cubic" the defaut for everyone? Is this Gentoo specific? Is there
a reason I've had it chosen over BIC for me by Gentoo magic? (I've not
done any TCP tuning myself - everything is default on this score... I
built my own kernel - but only to enable unrelated options.)
(I think) I'm using a vanilla kernel configuration with respect to
networking... uname reports "2.6.23-gentoo-r3".
$ syctl net.iv4
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_retrans_collapse = 1
net.ipv4.ip_forward = 1
net.ipv4.ip_default_ttl = 64
net.ipv4.ip_no_pmtu_disc = 0
net.ipv4.ip_nonlocal_bind = 0
net.ipv4.tcp_syn_retries = 5
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_max_orphans = 32768
net.ipv4.tcp_max_tw_buckets = 180000
net.ipv4.ipfrag_high_thresh = 262144
net.ipv4.ipfrag_low_thresh = 196608
net.ipv4.ip_dynaddr = 0
net.ipv4.ipfrag_time = 30
net.ipv4.tcp_keepalive_time = 7200
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_intvl = 75
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_retries2 = 15
net.ipv4.tcp_fin_timeout = 60
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_abort_on_overflow = 0
net.ipv4.tcp_stdurg = 0
net.ipv4.tcp_rfc1337 = 0
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.ip_local_port_range = 32768 61000
net.ipv4.icmp_echo_ignore_all = 0
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.icmp_errors_use_inbound_ifaddr = 0
net.ipv4.route.min_delay = 2
net.ipv4.route.max_delay = 10
net.ipv4.route.gc_thresh = 32768
net.ipv4.route.max_size = 524288
net.ipv4.route.gc_min_interval = 0
net.ipv4.route.gc_min_interval_ms = 500
net.ipv4.route.gc_timeout = 300
net.ipv4.route.gc_interval = 60
net.ipv4.route.redirect_load = 5
net.ipv4.route.redirect_number = 9
net.ipv4.route.redirect_silence = 5120
net.ipv4.route.error_cost = 250
net.ipv4.route.error_burst = 1250
net.ipv4.route.gc_elasticity = 8
net.ipv4.route.mtu_expires = 600
net.ipv4.route.min_pmtu = 552
net.ipv4.route.min_adv_mss = 256
net.ipv4.route.secret_interval = 600
net.ipv4.igmp_max_memberships = 20
net.ipv4.igmp_max_msf = 10
net.ipv4.inet_peer_threshold = 65664
net.ipv4.inet_peer_minttl = 120
net.ipv4.inet_peer_maxttl = 600
net.ipv4.inet_peer_gc_mintime = 10
net.ipv4.inet_peer_gc_maxtime = 120
net.ipv4.tcp_orphan_retries = 0
net.ipv4.tcp_fack = 1
net.ipv4.tcp_reordering = 3
net.ipv4.tcp_ecn = 0
net.ipv4.tcp_dsack = 1
net.ipv4.tcp_mem = 96576 128768 193152
net.ipv4.tcp_wmem = 4096 16384 4120576
net.ipv4.tcp_rmem = 4096 87380 4120576
net.ipv4.tcp_app_win = 31
net.ipv4.tcp_adv_win_scale = 2
net.ipv4.icmp_ratelimit = 250
net.ipv4.icmp_ratemask = 6168
net.ipv4.tcp_tw_reuse = 0
net.ipv4.tcp_frto = 0
net.ipv4.tcp_frto_response = 0
net.ipv4.tcp_low_latency = 0
net.ipv4.ipfrag_secret_interval = 600
net.ipv4.ipfrag_max_dist = 64
net.ipv4.tcp_no_metrics_save = 0
net.ipv4.tcp_moderate_rcvbuf = 1
net.ipv4.tcp_tso_win_divisor = 3
net.ipv4.tcp_congestion_control = cubic
net.ipv4.tcp_abc = 0
net.ipv4.tcp_mtu_probing = 0
net.ipv4.tcp_base_mss = 512
net.ipv4.tcp_workaround_signed_windows = 0
net.ipv4.tcp_slow_start_after_idle = 1
net.ipv4.tcp_available_congestion_control = cubic reno
net.ipv4.tcp_allowed_congestion_control = cubic reno
net.ipv4.tcp_max_ssthresh = 0
net.ipv4.neigh.default.mcast_solicit = 3
net.ipv4.neigh.default.ucast_solicit = 3
net.ipv4.neigh.default.app_solicit = 0
net.ipv4.neigh.default.retrans_time = 100
net.ipv4.neigh.default.base_reachable_time = 30
net.ipv4.neigh.default.delay_first_probe_time = 5
net.ipv4.neigh.default.gc_stale_time = 60
net.ipv4.neigh.default.unres_qlen = 3
net.ipv4.neigh.default.proxy_qlen = 64
net.ipv4.neigh.default.anycast_delay = 100
net.ipv4.neigh.default.proxy_delay = 80
net.ipv4.neigh.default.locktime = 100
net.ipv4.neigh.default.gc_interval = 30
net.ipv4.neigh.default.gc_thresh1 = 128
net.ipv4.neigh.default.gc_thresh2 = 512
net.ipv4.neigh.default.gc_thresh3 = 1024
net.ipv4.neigh.default.retrans_time_ms = 1000
net.ipv4.neigh.default.base_reachable_time_ms = 30000
net.ipv4.neigh.eth0.mcast_solicit = 3
net.ipv4.neigh.eth0.ucast_solicit = 3
net.ipv4.neigh.eth0.app_solicit = 0
net.ipv4.neigh.eth0.retrans_time = 100
net.ipv4.neigh.eth0.base_reachable_time = 30
net.ipv4.neigh.eth0.delay_first_probe_time = 5
net.ipv4.neigh.eth0.gc_stale_time = 60
net.ipv4.neigh.eth0.unres_qlen = 3
net.ipv4.neigh.eth0.proxy_qlen = 64
net.ipv4.neigh.eth0.anycast_delay = 100
net.ipv4.neigh.eth0.proxy_delay = 80
net.ipv4.neigh.eth0.locktime = 100
net.ipv4.neigh.eth0.retrans_time_ms = 1000
net.ipv4.neigh.eth0.base_reachable_time_ms = 30000
net.ipv4.neigh.lo.mcast_solicit = 3
net.ipv4.neigh.lo.ucast_solicit = 3
net.ipv4.neigh.lo.app_solicit = 0
net.ipv4.neigh.lo.retrans_time = 100
net.ipv4.neigh.lo.base_reachable_time = 30
net.ipv4.neigh.lo.delay_first_probe_time = 5
net.ipv4.neigh.lo.gc_stale_time = 60
net.ipv4.neigh.lo.unres_qlen = 3
net.ipv4.neigh.lo.proxy_qlen = 64
net.ipv4.neigh.lo.anycast_delay = 100
net.ipv4.neigh.lo.proxy_delay = 80
net.ipv4.neigh.lo.locktime = 100
net.ipv4.neigh.lo.retrans_time_ms = 1000
net.ipv4.neigh.lo.base_reachable_time_ms = 30000
net.ipv4.neigh.sit0.mcast_solicit = 3
net.ipv4.neigh.sit0.ucast_solicit = 3
net.ipv4.neigh.sit0.app_solicit = 0
net.ipv4.neigh.sit0.retrans_time = 100
net.ipv4.neigh.sit0.base_reachable_time = 30
net.ipv4.neigh.sit0.delay_first_probe_time = 5
net.ipv4.neigh.sit0.gc_stale_time = 60
net.ipv4.neigh.sit0.unres_qlen = 3
net.ipv4.neigh.sit0.proxy_qlen = 64
net.ipv4.neigh.sit0.anycast_delay = 100
net.ipv4.neigh.sit0.proxy_delay = 80
net.ipv4.neigh.sit0.locktime = 100
net.ipv4.neigh.sit0.retrans_time_ms = 1000
net.ipv4.neigh.sit0.base_reachable_time_ms = 30000
net.ipv4.conf.all.forwarding = 1
net.ipv4.conf.all.mc_forwarding = 0
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.secure_redirects = 1
net.ipv4.conf.all.shared_media = 1
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.all.send_redirects = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.proxy_arp = 0
net.ipv4.conf.all.medium_id = 0
net.ipv4.conf.all.bootp_relay = 0
net.ipv4.conf.all.log_martians = 0
net.ipv4.conf.all.tag = 0
net.ipv4.conf.all.arp_filter = 0
net.ipv4.conf.all.arp_announce = 0
net.ipv4.conf.all.arp_ignore = 0
net.ipv4.conf.all.arp_accept = 0
net.ipv4.conf.all.disable_xfrm = 0
net.ipv4.conf.all.disable_policy = 0
net.ipv4.conf.all.force_igmp_version = 0
net.ipv4.conf.all.promote_secondaries = 0
net.ipv4.conf.default.forwarding = 1
net.ipv4.conf.default.mc_forwarding = 0
net.ipv4.conf.default.accept_redirects = 1
net.ipv4.conf.default.secure_redirects = 1
net.ipv4.conf.default.shared_media = 1
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.send_redirects = 1
net.ipv4.conf.default.accept_source_route = 1
net.ipv4.conf.default.proxy_arp = 0
net.ipv4.conf.default.medium_id = 0
net.ipv4.conf.default.bootp_relay = 0
net.ipv4.conf.default.log_martians = 0
net.ipv4.conf.default.tag = 0
net.ipv4.conf.default.arp_filter = 0
net.ipv4.conf.default.arp_announce = 0
net.ipv4.conf.default.arp_ignore = 0
net.ipv4.conf.default.arp_accept = 0
net.ipv4.conf.default.disable_xfrm = 0
net.ipv4.conf.default.disable_policy = 0
net.ipv4.conf.default.force_igmp_version = 0
net.ipv4.conf.default.promote_secondaries = 0
net.ipv4.conf.eth0.forwarding = 1
net.ipv4.conf.eth0.mc_forwarding = 0
net.ipv4.conf.eth0.accept_redirects = 1
net.ipv4.conf.eth0.secure_redirects = 1
net.ipv4.conf.eth0.shared_media = 1
net.ipv4.conf.eth0.rp_filter = 1
net.ipv4.conf.eth0.send_redirects = 1
net.ipv4.conf.eth0.accept_source_route = 1
net.ipv4.conf.eth0.proxy_arp = 0
net.ipv4.conf.eth0.medium_id = 0
net.ipv4.conf.eth0.bootp_relay = 0
net.ipv4.conf.eth0.log_martians = 0
net.ipv4.conf.eth0.tag = 0
net.ipv4.conf.eth0.arp_filter = 0
net.ipv4.conf.eth0.arp_announce = 0
net.ipv4.conf.eth0.arp_ignore = 0
net.ipv4.conf.eth0.arp_accept = 0
net.ipv4.conf.eth0.disable_xfrm = 0
net.ipv4.conf.eth0.disable_policy = 0
net.ipv4.conf.eth0.force_igmp_version = 0
net.ipv4.conf.eth0.promote_secondaries = 0
net.ipv4.conf.lo.forwarding = 1
net.ipv4.conf.lo.mc_forwarding = 0
net.ipv4.conf.lo.accept_redirects = 1
net.ipv4.conf.lo.secure_redirects = 1
net.ipv4.conf.lo.shared_media = 1
net.ipv4.conf.lo.rp_filter = 1
net.ipv4.conf.lo.send_redirects = 1
net.ipv4.conf.lo.accept_source_route = 1
net.ipv4.conf.lo.proxy_arp = 0
net.ipv4.conf.lo.medium_id = 0
net.ipv4.conf.lo.bootp_relay = 0
net.ipv4.conf.lo.log_martians = 0
net.ipv4.conf.lo.tag = 0
net.ipv4.conf.lo.arp_filter = 0
net.ipv4.conf.lo.arp_announce = 0
net.ipv4.conf.lo.arp_ignore = 0
net.ipv4.conf.lo.arp_accept = 0
net.ipv4.conf.lo.disable_xfrm = 1
net.ipv4.conf.lo.disable_policy = 1
net.ipv4.conf.lo.force_igmp_version = 0
net.ipv4.conf.lo.promote_secondaries = 0
net.ipv4.conf.sit0.forwarding = 1
net.ipv4.conf.sit0.mc_forwarding = 0
net.ipv4.conf.sit0.accept_redirects = 1
net.ipv4.conf.sit0.secure_redirects = 1
net.ipv4.conf.sit0.shared_media = 1
net.ipv4.conf.sit0.rp_filter = 1
net.ipv4.conf.sit0.send_redirects = 1
net.ipv4.conf.sit0.accept_source_route = 1
net.ipv4.conf.sit0.proxy_arp = 0
net.ipv4.conf.sit0.medium_id = 0
net.ipv4.conf.sit0.bootp_relay = 0
net.ipv4.conf.sit0.log_martians = 0
net.ipv4.conf.sit0.tag = 0
net.ipv4.conf.sit0.arp_filter = 0
net.ipv4.conf.sit0.arp_announce = 0
net.ipv4.conf.sit0.arp_ignore = 0
net.ipv4.conf.sit0.arp_accept = 0
net.ipv4.conf.sit0.disable_xfrm = 0
net.ipv4.conf.sit0.disable_policy = 0
net.ipv4.conf.sit0.force_igmp_version = 0
net.ipv4.conf.sit0.promote_secondaries = 0
net.ipv4.netfilter.ip_conntrack_generic_timeout = 600
net.ipv4.netfilter.ip_conntrack_sctp_timeout_closed = 10
net.ipv4.netfilter.ip_conntrack_sctp_timeout_cookie_wait = 3
net.ipv4.netfilter.ip_conntrack_sctp_timeout_cookie_echoed = 3
net.ipv4.netfilter.ip_conntrack_sctp_timeout_established = 432000
net.ipv4.netfilter.ip_conntrack_sctp_timeout_shutdown_sent = 0
net.ipv4.netfilter.ip_conntrack_sctp_timeout_shutdown_recd = 0
net.ipv4.netfilter.ip_conntrack_sctp_timeout_shutdown_ack_sent = 3
net.ipv4.netfilter.ip_conntrack_tcp_timeout_syn_sent = 120
net.ipv4.netfilter.ip_conntrack_tcp_timeout_syn_recv = 60
net.ipv4.netfilter.ip_conntrack_tcp_timeout_established = 432000
net.ipv4.netfilter.ip_conntrack_tcp_timeout_fin_wait = 120
net.ipv4.netfilter.ip_conntrack_tcp_timeout_close_wait = 60
net.ipv4.netfilter.ip_conntrack_tcp_timeout_last_ack = 30
net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait = 120
net.ipv4.netfilter.ip_conntrack_tcp_timeout_close = 10
net.ipv4.netfilter.ip_conntrack_tcp_timeout_max_retrans = 300
net.ipv4.netfilter.ip_conntrack_tcp_loose = 1
net.ipv4.netfilter.ip_conntrack_tcp_be_liberal = 0
net.ipv4.netfilter.ip_conntrack_tcp_max_retrans = 3
net.ipv4.netfilter.ip_conntrack_udp_timeout = 30
net.ipv4.netfilter.ip_conntrack_udp_timeout_stream = 180
net.ipv4.netfilter.ip_conntrack_icmp_timeout = 30
net.ipv4.netfilter.ip_conntrack_sctp_timeout_established = 432000
net.ipv4.netfilter.ip_conntrack_sctp_timeout_shutdown_sent = 0
net.ipv4.netfilter.ip_conntrack_sctp_timeout_shutdown_recd = 0
net.ipv4.netfilter.ip_conntrack_sctp_timeout_shutdown_ack_sent = 3
net.ipv4.netfilter.ip_conntrack_tcp_timeout_syn_sent = 120
net.ipv4.netfilter.ip_conntrack_tcp_timeout_syn_recv = 60
net.ipv4.netfilter.ip_conntrack_tcp_timeout_established = 432000
net.ipv4.netfilter.ip_conntrack_tcp_timeout_fin_wait = 120
net.ipv4.netfilter.ip_conntrack_tcp_timeout_close_wait = 60
net.ipv4.netfilter.ip_conntrack_tcp_timeout_last_ack = 30
net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait = 120
net.ipv4.netfilter.ip_conntrack_tcp_timeout_close = 10
net.ipv4.netfilter.ip_conntrack_tcp_timeout_max_retrans = 300
net.ipv4.netfilter.ip_conntrack_tcp_loose = 1
net.ipv4.netfilter.ip_conntrack_tcp_be_liberal = 0
net.ipv4.netfilter.ip_conntrack_tcp_max_retrans = 3
net.ipv4.netfilter.ip_conntrack_udp_timeout = 30
net.ipv4.netfilter.ip_conntrack_udp_timeout_stream = 180
net.ipv4.netfilter.ip_conntrack_icmp_timeout = 30
net.ipv4.netfilter.ip_conntrack_max = 65536
net.ipv4.netfilter.ip_conntrack_count = 15
net.ipv4.netfilter.ip_conntrack_buckets = 16384
net.ipv4.netfilter.ip_conntrack_checksum = 1
net.ipv4.netfilter.ip_conntrack_log_invalid = 0
net.ipv4.ip_queue_maxlen = 1024
