Copyright (c) 2010-2011 The FreeBSD Foundation All rights reserved. This documentation was written at the Centre for Advanced Internet Architectures, Swinburne University of Technology, Melbourne, Australia by David Hayes and Lawrence Stewart 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 copyri...
NAMEmod_cc - Modular congestion control
DESCRIPTIONThe modular congestion control framework allows the TCP implementation to dynamically change the congestion control algorithm used by new and existing connections. Algorithms are identified by a unique ascii(7) name. Algorithm modules can be compiled into the kernel or loaded as kernel modules using the kld(4) facility.
The default algorithm is NewReno, and all connections use the default unless explicitly overridden using the TCP_CONGESTION socket option (see tcp(4) for details). The default can be changed using a sysctl(3) MIB variable detailed in the Sx MIB Variables section below.
Algorithm specific parameters can be set or queried using the TCP_CCALGOOPT socket option (see tcp(4) for details). Callers must pass a pointer to an algorithm specific data, and specify its size.
MIB VariablesThe framework exposes the following variables in the net.inet.tcp.cc branch of the sysctl(3) MIB:
- Read-only list of currently available congestion control algorithms by name.
- Returns the current default congestion control algorithm when read, and changes the default when set. When attempting to change the default algorithm, this variable should be set to one of the names listed by the net.inet.tcp.cc.available MIB variable.
SEE ALSOcc_cdg4, cc_chd4, cc_cubic4, cc_dctcp4, cc_hd4, cc_htcp4, cc_newreno4, cc_vegas4, tcp(4), mod_cc9
ACKNOWLEDGEMENTSDevelopment 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.
HISTORYThe sysctl Cm net.inet.tcp.syncookies modular congestion control framework first appeared in Fx 9.0 .
The framework 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:
AUTHORSAn -nosplit The sysctl Cm net.inet.tcp.syncookies facility was written by An Lawrence Stewart Aq Mt lstewart@FreeBSD.org , An James Healy Aq Mt firstname.lastname@example.org and An David Hayes Aq Mt email@example.com .
This manual page was written by An David Hayes Aq Mt firstname.lastname@example.org and An Lawrence Stewart Aq Mt lstewart@FreeBSD.org .