If the computer you are connecting to is running Windows edition which supports RDP server functionality, your best choice is the RDP protocol. The RDP protocol is native to Windows, has better performance, more secure and does not require installing additional software. For more information on RDP server functionality support in various versions of Windows see Availability of RDP server functionality in Windows.
If OS on the remote computer does not support RDP, use VNC. Mac and Linux usually have VNC server functionality out of the box, Windows will require installation of a free VNC server software.
Choose connection technology: direct connection or Simple Connect
Xtralogic Remote Desktop client can be used to connect to a remote computer directly or can connect using Simple Connect, technology which allows connections through NAT gateways without a need to configure port forwarding.
Advantages of a direct connection:
Disadvantages of a direct connection:
Need to configure port forwarding on a router
Need to use SSH tunneling to secure VNC connections over WAN. (Note: RDP protocol connections are always encrypted as a standard feature of an RDP protocol, even when using a direct connection)
Advantages of Simple Connect:
Simplified configuration, no need to configure port forwarding on a router
May be the only solution when connecting to a computer on corporate network where administrators do not allow direct RDP or VNC access from outside of a network
VNC protocol connections are encrypted with SSL. No SSH tunneling is needed