sysctl: Disable SACK

This is only useful on connections with a lot of packet loss
and increases bandwidth on a regular internet connection -
especially when there is limited computing power on the system.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/config/etc/sysctl.conf b/config/etc/sysctl.conf
index d11e53c88db373ac410f4490a492d4cf37d737d8..c8b1bb112872039751c7ac396f5ff2d1b2ded51c 100644 (file)
--- a/config/etc/sysctl.conf
+++ b/config/etc/sysctl.conf
@@ -81,6 +81,15 @@ net.ipv4.tcp_rmem = 4096 87380 16777216
 net.ipv4.tcp_wmem = 4096 16384 16777216
 net.ipv4.udp_mem = 3145728 4194304 16777216
 
+# We disable selective ACKs because it has some rather large overhead
+# which can be felt on systems with little CPU power and this technology
+# is only helpful on connections that have a lot of packet loss
+net.ipv4.tcp_sack = 0
+
+# Disable timestamp generation which is only needed for SACK and has
+# some overhead which we can save
+net.ipv4.tcp_timestamps = 0
+
 # Prefer low latency over higher throughput
 net.ipv4.tcp_low_latency=1