Hi,
I am having some issues with HTTP traffic through my VPN. The overall throughput isn't optimal, it's not bad by any means but I'm looking for ways to increase the overall performance for more consistent results. Currently our test setup is a single core VDS running Ubuntu 13.04 on an Xeon X5675. I don't believe these specs are a bottle neck as CPU peaks at 20% during a speedtest or extended download. The server also has full access to a highly underused Gbps port.
Server config
port 1194
proto tcp
;proto udp
;dev tap
dev tun
;dev-node MyTap
ca ca.crt
cert server.crt
key server.key # This file should be kept secret
dh dh2048.pem
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
push "redirect-gateway def1 bypass-dhcp"
push "dhcp-option DNS 8.8.4.4"
push "dhcp-option DNS 8.8.8.8"
keepalive 10 120
;comp-lzo
persist-key
persist-tun
status openvpn-status.log
verb 3
Client config
client
;dev tap
dev tun
proto tcp
;proto udp
remote 66.151.138.75 1194
;remote my-server-2 1194
;remote-random
resolv-retry infinite
nobind
persist-key
persist-tun
ca ca.crt
cert client.crt
key client.key
ns-cert-type server
;comp-lzo
verb 3
Things I've tried to increase overall performance..
1. Compression on/off - had very little affect
2. Disabling encryption - made it worse
3. Switching from UDP to TCP - about a 200-300KB/s improvement
4. playing with snd/rec window sizes on the server - No noticeable difference
While connected to the VPN general performance is good. Very small ping increase, speedtest sites show full line speed (I believe this is due to them opening multiple connections) and FTP works well. However, pure HTTP performance still suffers a bit. Generally we see 1.7Mb/s from a known site and anywhere from 400-900Kb/s from generic download sites.
