Slow VPN speed although Softether Speedtest is max speed

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nehor
Posts: 1
Joined: Mon Oct 21, 2019 3:42 am

Slow VPN speed although Softether Speedtest is max speed

Post by nehor » Mon Oct 21, 2019 3:50 am

Hello guys!

I only get 130 Mbit download with SoftEther. When I test with the Softether Speed measurement tool (connected to my VPN server), I get my full client ISP speed of about 400 Mbit. I also performed a speedtest on http://speedtest.net/ where with Softether I only get 130 Mbit, while without VPN I get full speed. When wgetting a big file from OVH with the VPN server, the server downloads with over 800 Mbit (the VPN server is also rented from the same server provider as the speedtest is hosted on, OVH, and is a strong machine with a good connection)

My upload speed is 20 Mbit and I get 20 Mbit upload on VPN too.

SecureNAT is enabled. VoiP/QoS disabled. Data compression disabled. UDP accel enabled. I have tried 1, 16 and also 32 TCP connections, half duplex enabled and disabled. I have also tried about 4-5 different dedicated servers from different providers (Softether is always running on Ubuntu). I'm the only one using it. No special configuration was done other than SecureNAT and changing the DNS. I have also reformatted my own Windows client, it made no difference. MTU is set correctly to 1500.

I use an ASUS RT-AC5300 router. When I performed the speedtest on OVH with 130 Mbit I have also checked the router webinterface and it showed only a network bandwidth of 130 Mbit, too (meaning there is no additional overhead from Home to VPN)

So far I haven't tried not using SecureNAT and using the local bridge instead but I haven't figured out how to use that correctly yet and I have read that this rather decreases the performance as well.

Any tips are welcome!

sky59
Posts: 241
Joined: Tue Sep 11, 2018 5:58 pm

Re: Slow VPN speed although Softether Speedtest is max speed

Post by sky59 » Mon Oct 21, 2019 6:57 am

you CAN NOT get more download over SE as upload on ISP !

ozone
Posts: 61
Joined: Thu Sep 19, 2019 7:18 pm

Re: Slow VPN speed although Softether Speedtest is max speed

Post by ozone » Mon Oct 21, 2019 9:01 pm

you CAN NOT get more download over SE as upload on ISP !
Hahaha, that was exactly what I was thinking.....

In general, to improve speed I would try to avoid pushing the traffic through the Securenat function if possible.
Also the encryption level, the "type" of vpn you chose, as does the client you used, they all dictate the actual real-iife speeds.

Just play with the settings and observe the effects on the speed.
Optimize from there.

Oh yeah, and of course preferably use a provider with symmetrical up/down ratio if you like "to internet" over vpn, as traffic has to go over it both ways.

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