Final commit to round out the "Five New TCP Congestion Control Algorithms for

FreeBSD" FreeBSD Foundation funded project.

- Add new man pages for the modular congestion control, Khelp and Hhook
  frameworks (cc.4, cc.9, khelp.9 and hhook.9).

- Add new man pages for each available congestion control algorithm (cc_chd.4,
  cc_cubic.4, cc_hd.4, cc_htcp.4, cc_newreno.4 and cc_vegas.4).

- Add a new man page for the Enhanced Round Trip Time (ERTT) Khelp module
  (h_ertt.4).

- Update the TCP (tcp.4) man page to mention the TCP_CONGESTION socket option,
  cross reference to cc.4 and remove references to the retired
  "net.inet.tcp.newreno" sysctl MIB variable.

In collaboration with:	David Hayes <dahayes at swin edu au> and
				Grenville Armitage <garmitage at swin edu au>
Sponsored by:	FreeBSD Foundation
MFC after:	3 months

1 files changed, 114 insertions, 0 deletions

diff --git a/share/man/man4/cc_cubic.4 b/share/man/man4/cc_cubic.4
new file mode 100644
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+++ b/share/man/man4/cc_cubic.4
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+.\"
+.\" Copyright (c) 2009 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, 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 February 15, 2011
+.Dt CC_CUBIC 4
+.Os
+.Sh NAME
+.Nm cc_cubic
+.Nd CUBIC Congestion Control Algorithm
+.Sh DESCRIPTION
+The CUBIC 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.
+During regular operation, the window increase function follows a cubic function,
+with the inflection point set to be the congestion window value reached at the
+last congestion event.
+CUBIC also calculates an estimate of the congestion window that NewReno would
+have achieved at a given time after a congestion event.
+When updating the congestion window, the algorithm will choose the larger of the
+calculated CUBIC and estimated NewReno windows.
+.Pp
+CUBIC also backs off less on congestion by changing the multiplicative decrease
+factor from 1/2 (used by standard NewReno TCP) to 4/5.
+.Pp
+The implementation was done in a clean-room fashion, and is based on the
+Internet Draft and paper referenced in the
+.Sx SEE ALSO
+section below.
+.Sh MIB Variables
+There are currently no tunable MIB variables.
+.Sh SEE ALSO
+.Xr cc 4 ,
+.Xr cc_chd 4 ,
+.Xr cc_hd 4 ,
+.Xr cc_htcp 4 ,
+.Xr cc_newreno 4 ,
+.Xr cc_vegas 4 ,
+.Xr tcp 4 ,
+.Xr cc 9
+.Rs
+.%A "Sangtae Ha"
+.%A "Injong Rhee"
+.%A "Lisong Xu"
+.%T "CUBIC for Fast Long-Distance Networks"
+.%U "http://tools.ietf.org/id/draft-rhee-tcpm-cubic-02.txt"
+.Re
+.Rs
+.%A "Sangtae Ha"
+.%A "Injong Rhee"
+.%A "Lisong Xu"
+.%T "CUBIC: a new TCP-friendly high-speed TCP variant"
+.%J "SIGOPS Oper. Syst. Rev."
+.%V "42"
+.%N "5"
+.%D "July 2008"
+.%P "64-74"
+.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 2009 by Lawrence Stewart whilst studying at
+Swinburne University's Centre for Advanced Internet Architectures, Melbourne,
+Australia.
+More details are available at:
+.Pp
+http://caia.swin.edu.au/urp/newtcp/
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+congestion control module and this manual page were written by
+.An Lawrence Stewart Aq lstewart@FreeBSD.org
+and
+.An David Hayes Aq david.hayes@ieee.org .