SoftEther VPN User Forum

Hello guys,

I'm testing VPN Server as Remote Connection.
Routing, ping and throughput is ok.
However RDP sessions is very slow. Did packet pacture and saw a lot of TCP retransmissions (attached).
I saw this before in other tunneling situation because RDP is sensitive to fragmentation, where adjusting MTU resolved issue.
Could someone help me troubleshoot this case?

Environment:
Tested VPN Server in Ubuntu 14 and Centos 6.5.
Client connecting to VPN Server through HTTPS/443.
Firewall doing Full DNAT to Internal VPN Server.
Bridged to local LAN and getting IP from local DHCP Server.
RDP Server (2008 R2) is on the same network segment.

I think TCP retransmissions doesn't happen.
Each packet is sent just once.

Could you try to disable the NAT-T?
Because packet loss of UDP may cause this problem.

Hello,

I'm using vpn over HTTPS, tried with 5555, too.
Also, VPNServer is inside the branch network published with DNAT. And on client side there's a NAT but allowing all traffic to outgoing.

Does SoftEther VPN client connect to the VPN server with TCP?
Could you confirm method of connection by log of VPN sever?