FreeBSD Manual Pages
CC_NEWRENO(4) FreeBSD Kernel Interfaces Manual CC_NEWRENO(4) NAME cc_newreno -- NewReno Congestion Control Algorithm SYNOPSIS #include <netinet/cc/cc_newreno.h> DESCRIPTION The NewReno congestion control algorithm is the default for TCP. Details about the algorithm can be found in RFC5681. Socket Options The cc_newreno module supports a number of socket options under TCP_CCAL- GOOPT (refer to tcp(4) and mod_cc(9) for details) which can be set with setsockopt(2) and tested with getsockopt(2). The cc_newreno socket op- tions use this structure defined in <sys/netinet/cc/cc_newreno.h>: struct cc_newreno_opts { int name; uint32_t val; } CC_NEWRENO_BETA Multiplicative window decrease factor, specified as a percentage, applied to the congestion window in response to a congestion signal per: cwnd = (cwnd * CC_NEWRENO_BETA) / 100. Default is 50. CC_NEWRENO_BETA_ECN Multiplicative window decrease factor, specified as a percentage, applied to the congestion window in response to an ECN congestion signal when net.inet.tcp.cc.abe=1 per: cwnd = (cwnd * CC_NEWRENO_BETA_ECN) / 100. Default is 80. MIB Variables The algorithm exposes these variables in the net.inet.tcp.cc.newreno branch of the sysctl(3) MIB: beta Multiplicative window decrease factor, specified as a percent- age, applied to the congestion window in response to a conges- tion signal per: cwnd = (cwnd * beta) / 100. Default is 50. beta_ecn Multiplicative window decrease factor, specified as a percent- age, applied to the congestion window in response to an ECN congestion signal when net.inet.tcp.cc.abe=1 per: cwnd = (cwnd * beta_ecn) / 100. Default is 80. SEE ALSO cc_cdg(4), cc_chd(4), cc_cubic(4), cc_dctcp(4), cc_hd(4), cc_htcp(4), cc_vegas(4), mod_cc(4), tcp(4), mod_cc(9) Mark Allman, Vern Paxson, and Ethan Blanton, TCP Congestion Control, RFC 5681. Naeem Khademi, Michael Welzl, Grenville Armitage, and Gorry Fairhurst, TCP Alternative Backoff with ECN (ABE), RFC 8511. 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. HISTORY The cc_newreno congestion control algorithm first appeared in its modular form in FreeBSD 9.0. 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, Aus- tralia, which was made possible in part by a grant from the Cisco Univer- sity Research Program Fund at Community Foundation Silicon Valley. More details are available at: http://caia.swin.edu.au/urp/newtcp/ AUTHORS The cc_newreno congestion control module was written by James Healy <jimmy@deefa.com>, Lawrence Stewart <lstewart@FreeBSD.org> and David Hayes <david.hayes@ieee.org>. Support for TCP ABE was added by Tom Jones <tj@enoti.me>. This manual page was written by Lawrence Stewart <lstewart@FreeBSD.org>. FreeBSD 13.0 May 13, 2021 FreeBSD 13.0
NAME | SYNOPSIS | DESCRIPTION | Socket Options | MIB Variables | SEE ALSO | ACKNOWLEDGEMENTS | HISTORY | AUTHORS
Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=cc_newreno&sektion=4&manpath=FreeBSD+13.1-RELEASE+and+Ports>