git: f164c0c4a8 - main - Remove references to net.inet.tcp.inflight*

From: Mateusz Piotrowski <0mp_at_FreeBSD.org>
Date: Tue, 24 May 2022 13:55:45 UTC
The branch main has been updated by 0mp:

URL: https://cgit.FreeBSD.org/doc/commit/?id=f164c0c4a87ea07820bd10432a0f65c1fbcd5baa

commit f164c0c4a87ea07820bd10432a0f65c1fbcd5baa
Author:     Mateusz Piotrowski <0mp@FreeBSD.org>
AuthorDate: 2022-05-24 13:52:49 +0000
Commit:     Mateusz Piotrowski <0mp@FreeBSD.org>
CommitDate: 2022-05-24 13:52:49 +0000

    Remove references to net.inet.tcp.inflight*
    
    Those variables were removed over 12 years ago.
    
    See the 1c18314d17c6ce5 ("Remove the TCP inflight bandwidth limiter...")
    commit in the src tree.
---
 .../content/en/books/handbook/config/_index.adoc     | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/documentation/content/en/books/handbook/config/_index.adoc b/documentation/content/en/books/handbook/config/_index.adoc
index 5fcc5a350f..57e8faf96f 100644
--- a/documentation/content/en/books/handbook/config/_index.adoc
+++ b/documentation/content/en/books/handbook/config/_index.adoc
@@ -1540,26 +1540,6 @@ A value of `10000`, `20000` or `30000` may be reasonable. Consider firewall effe
 Some firewalls may block large ranges of ports, usually low-numbered ports, and expect systems to use higher ranges of ports for outgoing connections. 
 For this reason, it is not recommended that the value of `net.inet.ip.portrange.first` be lowered.
 
-==== `TCP` Bandwidth Delay Product
-
-`TCP` bandwidth delay product limiting can be enabled by setting the `net.inet.tcp.inflight.enable` man:sysctl[8] variable to `1`.
-This instructs the system to attempt to calculate the bandwidth delay product for each connection and limit the amount of data queued to the network to just the amount required to maintain optimum throughput.
-
-This feature is useful when serving data over modems, Gigabit Ethernet, high speed `WAN` links, or any other link with a high bandwidth delay product, especially when also using window scaling or when a large send window has been configured.
-When enabling this option, also set `net.inet.tcp.inflight.debug` to `0` to disable debugging.
-For production use, setting `net.inet.tcp.inflight.min` to at least `6144` may be beneficial.
-Setting high minimums may effectively disable bandwidth limiting, depending on the link.
-The limiting feature reduces the amount of data built up in intermediate route and switch packet queues and reduces the amount of data built up in the local host's interface queue.
-With fewer queued packets, interactive connections, especially over slow modems, will operate with lower _Round Trip Times_.
-This feature only effects server side data transmission such as uploading.
-It has no effect on data reception or downloading.
-
-Adjusting `net.inet.tcp.inflight.stab` is _not_ recommended.
-This parameter defaults to `20`, representing 2 maximal packets added to the bandwidth delay product window calculation.
-The additional window is required to stabilize the algorithm and improve responsiveness to changing conditions, but it can also result in higher man:ping[8] times over slow links, though still much lower than without the inflight algorithm.
-In such cases, try reducing this parameter to `15`, `10`, or `5` and reducing `net.inet.tcp.inflight.min` to a value such as `3500` to get the desired effect. 
-Reducing these parameters should be done as a last resort only.
-
 === Virtual Memory
 
 ==== `kern.maxvnodes`