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| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2007-09-20 11:35:26 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-10-10 16:52:11 -0700 |
| commit | cd99889c616afe1e8addcf28da505600c04f065a (patch) | |
| tree | 0e92f46d64661a74e605714356b93e4307e715cb /Documentation | |
| parent | 009a2e3e4ec395a290b9e4c7c9ff99296fd6b7d8 (diff) | |
| download | linux-stable-cd99889c616afe1e8addcf28da505600c04f065a.tar.gz linux-stable-cd99889c616afe1e8addcf28da505600c04f065a.tar.bz2 linux-stable-cd99889c616afe1e8addcf28da505600c04f065a.zip | |
[TCP] FRTO: Update sysctl documentation
Since the SACK enhanced FRTO was added, the code has been
under test numerous times so remove "experimental" claim
from the documentation. Also be a bit more verbose about
the usage.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 32c2e9da5f3a..6ae2feff3087 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -180,13 +180,20 @@ tcp_fin_timeout - INTEGER to live longer. Cf. tcp_max_orphans. tcp_frto - INTEGER - Enables F-RTO, an enhanced recovery algorithm for TCP retransmission + Enables Forward RTO-Recovery (F-RTO) defined in RFC4138. + F-RTO is an enhanced recovery algorithm for TCP retransmission timeouts. It is particularly beneficial in wireless environments where packet loss is typically due to random radio interference - rather than intermediate router congestion. If set to 1, basic - version is enabled. 2 enables SACK enhanced F-RTO, which is - EXPERIMENTAL. The basic version can be used also when SACK is - enabled for a flow through tcp_sack sysctl. + rather than intermediate router congestion. FRTO is sender-side + only modification. Therefore it does not require any support from + the peer, but in a typical case, however, where wireless link is + the local access link and most of the data flows downlink, the + faraway servers should have FRTO enabled to take advantage of it. + If set to 1, basic version is enabled. 2 enables SACK enhanced + F-RTO if flow uses SACK. The basic version can be used also when + SACK is in use though scenario(s) with it exists where FRTO + interacts badly with the packet counting of the SACK enabled TCP + flow. tcp_frto_response - INTEGER When F-RTO has detected that a TCP retransmission timeout was |