Page 1 of 1

throughput reduction at cellular network

Posted: Mon Aug 02, 2021 7:25 am
by yongpark
I built a VPN server and measured the throughput between server and client.

There are significant throughput reduction at cellular network. Throughput decreased by more than 60% compared to without a VPN connection.

By using WiFi without VPN, average throughput: 119Mbps
By using WiFi with VPN, average throughput: 108Mbps
By using 5G without VPn, average throughput: 100Mbps
By using 5G with VPN, average throughput: 35Mbps

I know that the throughput is lowered due to the encryption process of VPN. However, when connecting VPN server using a cellular network, is there any reason why the throughput is so significantly degraded compared to Ethernet?

The connection was TCP and i used iperf3 to measure throughput.

Thank you for answering. Have a nice day!

Re: throughput reduction at cellular network

Posted: Mon Aug 02, 2021 11:42 am
by chilinux
There is not enough details provided for someone to be able to reproduce your results.

Key details missing:

What version of OpenVPN Access Server are you using?
What version of the OpenVPN client are you using?
What operating system are you running the OpenVPN client on?
What operating system are you running iperf3 on?
What iperf3 options are you using? Can you provide the command line?
What device are you using to connect via 5G?
What phone carriers are you able to reproduce the results with?

Lastly, are you using the term WiFi and the term Ethernet to mean the same thing? They typically are not considered interchangeable terms. You didn't actually provide any wired result to compare.