SoftEther VPN User Forum

Hi guys,

I have measured the throughput between a SE server and client residing as VMs on the same host. Outside VPN they can talk 11 gbps (unidirectional). Inside SE VPN they talk at 0.9 gbps.

Even when I added a 3rd VM connected to the same server, the total server BW did not go over 0.9 gbps.

Both server and clients have plenty CPU and RAM so this is not a problem. Increasing the speed of the VPN adapter to the maximum allowed 2000 mbps did not help. I used iperf3 for testing. Same commands were used for both tests, outside VPN and inside. Both were running Windows Server 2016.

Is SE limited (hard-coded) at 1 gbps?

10x!
Sergiu

SoftEther doesn't limit bandwidth.

Did you enable encryption on VPN session?

Could you try to increase number of TCP connection of VPN?
SoftEther VPN use one thread per one TCP connection. So if the hosts have many cores, increasing connection is effective.
UDP may have opposite effect because UDP is processed in one thread.

Yes, I have enabled encryption. Is it single threaded? If yes, this is a major perf issue. Are there any plans for multi-thread?

Yes, I have tried to increase number of TCP connection. No use...

Please try to disable 'UDP acceleration'.