This paper describes the challenges to meet in order to enable effective real-time interaction over the Internet for the remote prototyping of automatic control solutions. The type of real-time interaction required for such a prototyping is the ability for an operator to adjust remotely the settings of a controlled system and to observe immediately the effects of this action on its dynamics. Solutions are proposed to keep a seamless degree of interactivity despite the Internet bandwidth variations. These solutions rely on an end-to-end adaptation scheme of the transmitted content. This scheme mimics the TCP communication protocol without showing the same drawbacks.