From: Rick Jones Date: Wed, 28 Nov 2012 09:53:10 +0000 (+0000) Subject: doc: make the description of how tcp_ecn works more explicit and clear X-Git-Tag: master-2012-12-14~5^2~171 X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=7e3a2dc52953f126103a36b33db1f57463fbbb8f;p=~andy%2Flinux doc: make the description of how tcp_ecn works more explicit and clear Make the description of how tcp_ecn works a bit more explicit and clear. Signed-off-by: Rick Jones Signed-off-by: David S. Miller --- diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 98ac0d7552a..c6d5fee888c 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -199,15 +199,16 @@ tcp_early_retrans - INTEGER Default: 2 tcp_ecn - INTEGER - Enable Explicit Congestion Notification (ECN) in TCP. ECN is only - used when both ends of the TCP flow support it. It is useful to - avoid losses due to congestion (when the bottleneck router supports - ECN). + Control use of Explicit Congestion Notification (ECN) by TCP. + ECN is used only when both ends of the TCP connection indicate + support for it. This feature is useful in avoiding losses due + to congestion by allowing supporting routers to signal + congestion before having to drop packets. Possible values are: - 0 disable ECN - 1 ECN enabled - 2 Only server-side ECN enabled. If the other end does - not support ECN, behavior is like with ECN disabled. + 0 Disable ECN. Neither initiate nor accept ECN. + 1 Always request ECN on outgoing connection attempts. + 2 Enable ECN when requested by incomming connections + but do not request ECN on outgoing connections. Default: 2 tcp_fack - BOOLEAN