SoftEther Server strange speed issue, please help me

[s-zoli]

I am new to linux and vpn, but successfully installed a SoftEther Server at home, using my Raspberry Pi.
I have a server at a premium VPS provider (without any limitations), and try to use it as a SoftEther Server

At home, my RPi is working great, without any problem
System: 4x0.9GHz CPU, 1GB RAM
OS: Raspbian Wheezy, 4.1.19
SoftEther: ARM, Version 4.21 Build 9613

At VPS I installed the same version of SoftEther Server
System: 4x2.8GHz CPU, 4GB RAM (virtualized)
OS: Debian, 3.16.0
Softether: x86, Version 4.21 Build 9613

Both SoftEther Server is configured exactly the same:
L2TP/IPsec, port 443, SecureNat.

After connecting the SoftEther at VPS, connection is working, got the bandwidth I expect, but after a few seconds the download speed got dropped to maximum 10-15kb/sec (no problem with upload)
Pinging is working, no dropped packets, but the throughput is horribly slow.
I got no cpu, neither internet bottleneck.

I tried rebuilding the SoftEther, reconfiguring it, using different ports, turning off the firewall, no success (at RPi, got working 1st try).
Asked a few friends to test both vpns, they got the same results.

At home I have 50/10 ADSL, SoftEther running in my RPi, working great, but my internet is slow and not working 24/7.
At VPS I can get 1000/1000 connection (at least 200/200), running 24/7, but I got the mentioned issue.

Has anybody encountered the same issue, any idea how can I fix that, or at least where to search the problem?
I really appreciate any idea or tips.

[s-zoli]

The same version of Windows client working good, when I use the RPi hosted SoftEther.
I also tried connecting from Linux (Debian x86), with the same result. (RPi SoftEther working, VPS SoftEther slow)

[thisjun]

Please check whether VPS and RPi are in same mode of SecureNAT .

[s-zoli]

thisjun wrote:
> Please check whether VPS and RPi are in same mode of SecureNAT .

I checked, it's the same.
Since then I have tried copy-paste the SoftEther config file from RPi to VPs, but at VPs it's not working well.

[thisjun]

What mode does the SecureNAT work in the VPS and RPi?
The mode automatically change. So, the mode can't be determined by configuration.

[s-zoli]

Thanks for everyone, trying to help me.
The problem is, that our ISP is limiting vpn connections.

[J1mbo]

run it over 443

[s-zoli]

As I mentioned before, tried different ports, including the 4 default and many others.

[raafat]

You have to switch to SESSL protocol over 443, your ISP is capable of knowing that you use L2TP/IPSec if they monitor your traffic, but with SSL the case is different.


Good luck.

[s-zoli]

You are right, that was the solution, many thanks. :)

[s-zoli]

flatoutcrazy wrote:
> Hello,
>
> i know this is getting old, but can you tell me how you switched to the
> SESSL protocol? maybe i'm missing the setting somewhere...
>
> Thanks.

I can't say, I switch to SESSL protocol, I just disabled every additional protocols (L2TP, MSPT, OpenVPNS...etc), that forced the SoftEther to use the built-in SSL encoded one.
Since then the vpn is working everywhere.