Connection not fully utilized



  • I have a 50Mbps fiber connection but with OpenVPN enabled I only get 22Mbps, but when I test with my 65Mbps LTE connection I get 60Mbps over OpenVPN.

    I've tried using a DD-WRT router with OpenVPN and I get ~45Mbps and same with the desktop OpenVPN client.

    What would cause such odd behavior? I used the same settings for both connections, only swapping the cables to test.  :o


  • Rebel Alliance Developer Netgate

    Could be that the fiber MTU is lower at some point along the path, so you need to reduce the packet sizes. Some difference in the settings between pfSense and DD-WRT may be breaking PMTUD or maybe it has some other difference.

    Without OpenVPN, do you ever get the full speed of that fiber? Maybe check for a duplex mismatch if you don't.



  • What exactly are you testing?  Are you connecting a remote site through the VPN, perhaps as a "road warrior"?  If so, the upload bandwidth will limit the download bandwidth of the remote site.  Is your fibre connection symetric or asymetric?  If asymentric, you will have different upload and download bandwidths.  My cell connections are symetric, but my cable connection is not.  What do you get if you run speedtest through your fibre connection?