RDP Sessios slow over VPN

Post your questions about SoftEther VPN software here. Please answer questions if you can afford.
Post Reply
skl
Posts: 4
Joined: Sun Mar 11, 2018 2:15 am

RDP Sessios slow over VPN

Post by skl » Mon Mar 12, 2018 1:12 pm

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.
Attachments
SoftEther_RDP.png

thisjun
Posts: 2676
Joined: Mon Feb 24, 2014 11:03 am

Re: RDP Sessios slow over VPN

Post by thisjun » Thu Mar 22, 2018 7:07 am

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.

skl
Posts: 4
Joined: Sun Mar 11, 2018 2:15 am

Re: RDP Sessios slow over VPN

Post by skl » Thu Mar 29, 2018 5:04 pm

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.

thisjun
Posts: 2676
Joined: Mon Feb 24, 2014 11:03 am

Re: RDP Sessios slow over VPN

Post by thisjun » Wed Apr 18, 2018 7:04 am

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

Post Reply