The roadmap for this chapter is best captured in diagram 1.1. The diagram shows the Internet Protocols that are concerend with the format and delivery of multimedia content. The chapter is mostly a microcosm of the book. which means that it covers these protocols largely in a bottom-up approach, starting with delivery of packets in the Internet, and ending with a description of some multimedia application protocols. In between, we take a look at content description, at network service models, and at middleware for creation, transport, control and retrieval of multimedia.