ResolutionParallels Virtuozzo Containers (herafter Virtuozzo) uses Microsoft's native Terminal Services (TS), which utilize the RDP (Remote Desktop Protocol) to provide direct access to the VE (Virtual Private Server) desktop for administrative purposes. Each VE has its own TS instance running inside which provides with RDP access to this VE.
Terminal Services on a Virtuozzo server are subject to Microsoft TS licensing: only 2 simultaneous RDP sessions are allowed by default.
It is important to note that these licenses define the number of simultaneous TS connections so you will only need to purchase enough licenses to satisfy this requirement. Terminal Server Licensing can be installed on any VE you like. Then it is necessary to point required VE to TS license server.
If you are planning to use more than 2 simultaneous Terminal Services connections you need to install additional TS licenses to your virtual machine running Virtuozzo.
Virtuozzo allows you to limit the amount of simultaneous RDP sessions opened to a VE ("Number of TS sessions" in QoS). This QoS setting allows you to provide fair distribution of TS licenses ensuring that VE cannot occupy all available TS licenses.
Starting from Virtuozzo 3.5.1 Service Pack 1 it is possible to connect into VE console session, so utilities like VNC, pcAnywhere, Radmin etc. ,are using the so-called Windows root session (or root console) to connect to a typical Windows 2003 server, can be used as well.