A prototype system based on an inverted pendulum is used to study the Quality of Service and discuss requirements of remote-experimentation systems utilized for carrying out control engineering experiments over the Internet. This class of applications involves the transmission over the network of a variety of data types with their own peculiar Quality of Service requirement. These data types include video and audio images from the process environment, signal traces related to the acquired measurements, control instructions sent to the process actuators, and other information concerning the states of the process. The set up includes a physical system (an inverted pendulum) as well as a local server fitted with a video camera, data acquisition boards, and network connectivity that permits interactions with remotely located clients. This paper discusses relevant issues of the design and presents a paradigm for operation based on a client-server configuration and a standard/master-client mode of service. The information streams involved in the process are classified in four groups of different transmission priorities, namely, a parameter stream, a data stream, an administrative stream, and an audio/video stream. This paper analyzes the performance and requirements of the system based on the results of transatlantic tests. The results of the analysis show that real-time remote-control experimentation over the Internet is in fact a new kind of network application featuring its own requirements that are different from those of related technologies used for video conferencing/broadcasting. In order to overcome the current lack of predictability of the Internet, the final section of the paper suggests improvements such as adapting the priority of the different streams to the Internet bandwidth and to the user's needs. (Author/CCM)