| mod_cc.4 (b8d60729deefa0bd13e6a395fcab4928e6e10445) | mod_cc.4 (a9696510f5caef4a7c525fcf4359597798829350) |
|---|---|
| 1.\" 2.\" Copyright (c) 2010-2011 The FreeBSD Foundation 3.\" All rights reserved. 4.\" 5.\" This documentation was written at the Centre for Advanced Internet 6.\" Architectures, Swinburne University of Technology, Melbourne, Australia by 7.\" David Hayes and Lawrence Stewart under sponsorship from the FreeBSD 8.\" Foundation. --- 69 unchanged lines hidden (view full) --- 78memory shortage as the new CC module malloc's memory, that prevented the 79switch is often transient. 80.Sh MIB Variables 81The framework exposes the following variables in the 82.Va net.inet.tcp.cc 83branch of the 84.Xr sysctl 3 85MIB: | 1.\" 2.\" Copyright (c) 2010-2011 The FreeBSD Foundation 3.\" All rights reserved. 4.\" 5.\" This documentation was written at the Centre for Advanced Internet 6.\" Architectures, Swinburne University of Technology, Melbourne, Australia by 7.\" David Hayes and Lawrence Stewart under sponsorship from the FreeBSD 8.\" Foundation. --- 69 unchanged lines hidden (view full) --- 78memory shortage as the new CC module malloc's memory, that prevented the 79switch is often transient. 80.Sh MIB Variables 81The framework exposes the following variables in the 82.Va net.inet.tcp.cc 83branch of the 84.Xr sysctl 3 85MIB: |
| 86.Bl -tag -width ".Va abe_frlossreduce" | 86.Bl -tag -width ".Va hystartplusplus.css_growth_div" |
| 87.It Va available 88Read-only list of currently available congestion control algorithms by name. 89.It Va algorithm 90Returns the current default congestion control algorithm when read, and changes 91the default when set. 92When attempting to change the default algorithm, this variable should be set to 93one of the names listed by the 94.Va net.inet.tcp.cc.available 95MIB variable. 96.It Va abe 97Enable support for RFC 8511, 98which alters the window decrease factor applied to the congestion window in 99response to an ECN congestion signal. 100Refer to individual congestion control man pages to determine if they implement 101support for ABE and for configuration details. 102.It Va abe_frlossreduce 103If non-zero, apply standard beta instead of ABE-beta during ECN-signalled 104congestion recovery episodes if loss also needs to be repaired. | 87.It Va available 88Read-only list of currently available congestion control algorithms by name. 89.It Va algorithm 90Returns the current default congestion control algorithm when read, and changes 91the default when set. 92When attempting to change the default algorithm, this variable should be set to 93one of the names listed by the 94.Va net.inet.tcp.cc.available 95MIB variable. 96.It Va abe 97Enable support for RFC 8511, 98which alters the window decrease factor applied to the congestion window in 99response to an ECN congestion signal. 100Refer to individual congestion control man pages to determine if they implement 101support for ABE and for configuration details. 102.It Va abe_frlossreduce 103If non-zero, apply standard beta instead of ABE-beta during ECN-signalled 104congestion recovery episodes if loss also needs to be repaired. |
| 105.It Va hystartplusplus.bblogs 106This boolean controls if black box logging will be done for hystart++ events. 107If set to zero (the default) no logging is performed. 108If set to one then black box logs will be generated on all hystart++ events. 109.It Va hystartplusplus.css_rounds 110This value controls the number of rounds that CSS runs for. 111The default value matches the current internet-draft of 5. 112.It Va hystartplusplus.css_growth_div 113This value controls the divisor applied to slowstart during CSS. 114The default value matches the current internet-draft of 4. 115.It Va hystartplusplus.n_rttsamples 116This value controls how many rtt samples must be collected in each round for 117hystart++ to be active. 118The default value matches the current internet-draft of 8. 119.It Va hystartplusplus.maxrtt_thresh 120This value controls the maximum rtt variance clamp when considering if CSS is needed. 121The default value matches the current internet-draft of 16000 (in microseconds). 122For further explanation please see the internet-draft. 123.It Va hystartplusplus.minrtt_thresh 124This value controls the minimum rtt variance clamp when considering if CSS is needed. 125The default value matches the current internet-draft of 4000 (in microseconds). 126For further explanation please see the internet-draft. |
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| 105.El 106.Pp 107Each congestion control module may also expose other MIB variables 108to control their behaviour. | 127.El 128.Pp 129Each congestion control module may also expose other MIB variables 130to control their behaviour. |
| 131Note that both newreno and cubic now support hystart++ based on the version 3 of the internet-draft. |
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| 109.Sh Kernel Configuration 110.Pp 111All of the available congestion control modules may also be loaded 112via kernel configutation options. 113A kernel configuration is required to have at least one congestion control 114algorithm built into it via kernel option and a system default specified. 115Compilation of the kernel will fail if these two conditions are not met. 116.Sh Kernel Configuration Options --- 72 unchanged lines hidden --- | 132.Sh Kernel Configuration 133.Pp 134All of the available congestion control modules may also be loaded 135via kernel configutation options. 136A kernel configuration is required to have at least one congestion control 137algorithm built into it via kernel option and a system default specified. 138Compilation of the kernel will fail if these two conditions are not met. 139.Sh Kernel Configuration Options --- 72 unchanged lines hidden --- |