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diff --git a/share/man/man4/cc_htcp.4 b/share/man/man4/cc_htcp.4 new file mode 100644 index 000000000000..45d00186c878 --- /dev/null +++ b/share/man/man4/cc_htcp.4 @@ -0,0 +1,136 @@ +.\" +.\" Copyright (c) 2008 Lawrence Stewart <lstewart@FreeBSD.org> +.\" Copyright (c) 2010-2011 The FreeBSD Foundation +.\" All rights reserved. +.\" +.\" Portions of this documentation were written at the Centre for Advanced +.\" Internet Architectures, Swinburne University of Technology, Melbourne, +.\" Australia by David Hayes under sponsorship from the FreeBSD Foundation. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR +.\" ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd September 15, 2011 +.Dt CC_HTCP 4 +.Os +.Sh NAME +.Nm cc_htcp +.Nd H-TCP Congestion Control Algorithm +.Sh DESCRIPTION +The H-TCP congestion control algorithm was designed to provide increased +throughput in fast and long-distance networks. +It attempts to maintain fairness when competing with legacy NewReno TCP in lower +speed scenarios where NewReno is able to operate adequately. +.Pp +The congestion window is increased as a function of the time elapsed since the +last congestion event. +The window increase algorithm operates like NewReno for the first second after a +congestion event, and then switches to a high-speed mode based on a quadratic +increase function. +.Pp +The implementation was done in a clean-room fashion, and is based on the +Internet Draft and other documents referenced in the +.Sx SEE ALSO +section below. +.Sh MIB Variables +The algorithm exposes the following tunable variables in the +.Va net.inet.tcp.cc.htcp +branch of the +.Xr sysctl 3 +MIB: +.Bl -tag -width ".Va adaptive_backoff" +.It Va adaptive_backoff +Controls use of the adaptive backoff algorithm, which is designed to keep +network queues non-empty during congestion recovery episodes. +Default is 0 (disabled). +.It Va rtt_scaling +Controls use of the RTT scaling algorithm, which is designed to make congestion +window increase during congestion avoidance mode invariant with respect to RTT. +Default is 0 (disabled). +.El +.Sh SEE ALSO +.Xr cc_chd 4 , +.Xr cc_cubic 4 , +.Xr cc_hd 4 , +.Xr cc_newreno 4 , +.Xr cc_vegas 4 , +.Xr mod_cc 4 , +.Xr tcp 4 , +.Xr mod_cc 9 +.Rs +.%A "D. Leith" +.%A "R. Shorten" +.%T "H-TCP: TCP Congestion Control for High Bandwidth-Delay Product Paths" +.%U "http://tools.ietf.org/id/draft-leith-tcp-htcp-06.txt" +.Re +.Rs +.%A "D. Leith" +.%A "R. Shorten" +.%A "T. Yee" +.%T "H-TCP: A framework for congestion control in high-speed and long-distance networks" +.%B "Proc. PFLDnet" +.%D "2005" +.Re +.Rs +.%A "G. Armitage" +.%A "L. Stewart" +.%A "M. Welzl" +.%A "J. Healy" +.%T "An independent H-TCP implementation under FreeBSD 7.0: description and observed behaviour" +.%J "SIGCOMM Comput. Commun. Rev." +.%V "38" +.%N "3" +.%D "July 2008" +.%P "27-38" +.Re +.Sh ACKNOWLEDGEMENTS +Development and testing of this software were made possible in part by grants +from the FreeBSD Foundation and Cisco University Research Program Fund at +Community Foundation Silicon Valley. +.Sh HISTORY +The +.Nm +congestion control module first appeared in +.Fx 9.0 . +.Pp +The module was first released in 2007 by James Healy and Lawrence Stewart whilst +working on the NewTCP research project at Swinburne University of Technology's +Centre for Advanced Internet Architectures, Melbourne, Australia, which was made +possible in part by a grant from the Cisco University Research Program Fund at +Community Foundation Silicon Valley. +More details are available at: +.Pp +http://caia.swin.edu.au/urp/newtcp/ +.Sh AUTHORS +.An -nosplit +The +.Nm +congestion control module was written by +.An James Healy Aq jimmy@deefa.com +and +.An Lawrence Stewart Aq lstewart@FreeBSD.org . +.Pp +This manual page was written by +.An Lawrence Stewart Aq lstewart@FreeBSD.org +and +.An David Hayes Aq david.hayes@ieee.org . |