Atman

at Red Hat Magazine one article is talk about TCP tuning parameters.

1. /proc/sys/net/core/rmem_max - Maximum TCP Receive Window.
2. /proc/sys/net/core/wmem_max - Maximum TCP Send Window.
3. /proc/sys/net/ipv4/tcp_timestamps - Timestamp ( RFC 1323) add 12 bytes to the TCP headers.
4. /proc/sys/net/ipv4/tcp_sack - TCP selective acknowledgments.
5. /proc/sys/net/ipv4/tcp_window_scaling - support for large TCP Windows (RFC 1323). Needs to be set to 1 if the Max TCP Window is over 65535.
6. mem_default = Default Receive Window.
7. rmem_max = Maximum Receive Window.
8. wmem_default = Default Send Window.
9. wmem_max = Maximum Send Window

中文补充:

1. /proc/sys/net/core/rmem_max — 最大的TCP数据接收缓冲

2. /proc/sys/net/core/wmem_max — 最大的TCP数据发送缓冲

3. /proc/sys/net/ipv4/tcp_timestamps — 时间戳在(请参考RFC 1323)TCP的包头增加12个字节

4. /proc/sys/net/ipv4/tcp_sack — TCP selective acknowledgments

5. /proc/sys/net/ipv4/tcp_window_scaling — 支持更大的TCP窗口. 如果TCP窗口最大超过65535(64K), 必须设置该数值为1

6. rmem_default — 默认的接收窗口大小

7. rmem_max — 接收窗口的最大大小

8. wmem_default — 默认的发送窗口大小

9. wmem_max — 发送窗口的最大大小

his method is place the code in /etc/rc.local .

echo 256960 > /proc/sys/net/core/rmem_default
echo 256960 > /proc/sys/net/core/rmem_max
echo 256960 > /proc/sys/net/core/wmem_default
echo 256960 > /proc/sys/net/core/wmem_max

echo 0 > /proc/sys/net/ipv4/tcp_timestamps
echo 1 > /proc/sys/net/ipv4/tcp_sack
echo 1 > /proc/sys/net/ipv4/tcp_window_scaling

and add following code in /etc/sysctl.conf

net.core.rmem_default = 256960
net.core.rmem_max = 256960
net.core.wmem_default = 256960
net.core.wmem_max = 256960

net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_sack =1
net.ipv4.tcp_window_scaling = 1

other articles links :

http://www.speedguide.net/read_articles.php?id=121