Speed

guyguy333

Hello,

I installed an openVPN server on my dedicated server (Debian) (1 Gbit/s). I need to use TCP and the port 443.
I use Tunnelblick on my mac (client)(OS X 10.6) and all works but I have low connetion.
Without openvpn tunnel => 11 Mbit/s and ping with server : 70ms
With openvpn tunnel => 4Mbit/s and ping with server : 120ms

How to incrase speed ?

Server configuration :

port 443
proto tcp
dev tun
ca ca.crt
cert Irina.crt
key Irina.key
dh dh1024.pem
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
push "route 192.168.0.0 255.255.255.0"
push "redirect-gateway def1"
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 8.8.4.4"
client-to-client
keepalive 10 120
comp-lzo
persist-key
persist-tun
status openvpn-status.log
verb 1
mute 10

Client configuration :

client
dev tun
proto tcp
remote 178.63.*.* 443
resolv-retry infinite
nobind
persist-key
persist-tun
ca /Users/guigui/Documents/VPN/ca.crt
cert /Users/guigui/Documents/VPN/guigui.crt
key /Users/guigui/Documents/VPN/guigui.key
comp-lzo
verb 3
mute 10

Thanks for your help.

janjust

add

tcp-nodelay

to the server and restart it.

guyguy333

Thank you for your reply

But I have an error and server doesn't want to start

"ovpn-server[8967]: Options error: Unrecognized option or missing parameter(s) in /etc/openvpn/server.conf:1: tcp-nodelay (2.1_rc11)"

janjust

openvpn 2.1_rc11 is grossly outdate - please update to 2.1.4 or 2.2.0 and try again.

guyguy333

Thank you, I compiled and installed openVPN 2.2.0
I use tcp-nodelay on the server.

New speed test :
Without openvpn tunnel => 11 Mbit/s and ping with server : 70ms
With openvpn tunnel => 5,7Mbit/s (vs 4Mbit/s) and ping with server : 80ms (vs 120ms)

Do you have any other solutions to increase speed ? Thank you !

janjust

speed tuning is a cumbersome process... try playing with

mssfix 1400
tun-mtu 1440

i.e. start out with the above numbers and go up and down a bit to see if it affects performance.

guyguy333

Best performances are with default value... If I go up or down, it decrease performance

janjust

hmmm for testing purposes, try disabling encryption altogether

cipher none
auth none
/code]

on both client and server ; it is possible that you're hitting some encryption speed bottleneck, although I wouldn't expect so soon.

guyguy333

It's strange, without encryption, the result of speed test is 3-4 Mbit/s ...
I tried to change the protocol to UDP (with encryption, only a change in the protocol) : 7-8Mbit/s !
I think that TCP protocol is the problem
Thank you

janjust

well, in general, you should not try to run tcp over tcp ; if the lower-level TCP connection experiences packet loss then your performance will be killed; it is actually best to run TCP connections over a UDP-based VPN and UDP connections over a TCP-based VPN 😉

the fact that performance does not increase when disabling encryption shows that it is indeed the TCP connection (at the lowest level) which is causing the problems. The only solution for that is: choose a better ISP 😉