Softether VPN slow throughput

I set up a Softether VPN on my Raspberry Pi per the instructions here, and I'm getting extremely low throughput when connecting to the VPN. My Internet connection to the Raspberry Pi is about 30 Mbit/s down and 3 Mbit/s up, yet when I connect to the VPN (on another connection that is equally as fast, if not faster), I only get about 1 Mbit/s down & up.
The CPU on the Pi is running at no more than ~5-15% with one connection, so it's not a problem with the hardware as far I as can tell.

How and why am I getting such terrible performance?

daviesgeek

Posted 2015-06-29T17:40:57.330

Reputation: 1 469

And please, if there's a better way to set this up, feel free to bash my setup. I went with this setup because it was easiest to setup with iOS/OS X devices, and I didn't have to run a VPS. I'm not terribly experienced with VPNs, so any extra information would be welcomed – daviesgeek – 2015-06-29T17:41:12.067

Answers

I got the same issue with yours. And I solved it by adding a tab and bridge device between the vhub and eth0. It look like this:

vhub <---> tap0 <---> br0 <---> eth0 (50 to 60 Mbps)

The default set up: vhub <---> eth0 (1 to 3 Mbps)

It also works for vmware if you use VMXNET3

Darwin Zeng

Posted 2015-06-29T17:40:57.330

Reputation: 11

Welcome to Super User! This looks like a good answer but you may wish to consider expanding it a bit with some details (e.g. what were the exact steps you took to do this, why you did this/your understanding of what the issue was, etc.) to help others that may not be as familiar with things as you are. – Anaksunaman – 2018-06-06T00:38:37.837

Few suggestions:

Connect to your VPN server within the same local LAN and test the speed. If you got good throughput with local LAN connection, it would be the networking issue, problem caused by the router, in between your two sites
Softether Linux VPN client has built-in throughput testing cmd: TrafficClient and TrafficServer; try to see what speed you can get with these commands
You also can try to increase the number of TCP connections with command: AccountDetailSet. That can improve your network throughput, too.

Hope it helps a bit.

Xu Dong Wu

Posted 2015-06-29T17:40:57.330

Reputation: 11