Distributed interactive media are media that involve communication over a computer network as well as user interactions with the medium itself. Examples of this kind of media are shared whiteboard presentations and networked computer games. One key problem of this media class is that a large amount of common functionality is currently redesigned and redeveloped for each single medium. In order to solve this problem we present a media model and an application level protocol called RTP/I. Derived from the experience gained with audio and video transmission using RTP, RTP/I is defined as a new protocol framework which reuses many aspects of RTP while it is thoroughly adapted to meet the demands of distributed interactive media. By identifying and supporting the common aspects of distributed interactive media RTP/I allows the reuse of key functionality in form of generic services. Furthermore RTP/I makes it possible for applications of different vendors to interact with each other in a standardized way.