Nowadays most people exploit the Internet to get contents such as web pages, music or video files. These users only value "what" they download and are not interested about "where" content is actually stored. The IP layer does the opposite and cares about the "where" and not about the "what". This contrast between the actual usage of the Internet and the service offered by the IP layer is deemed to be the source of several problems concerning usability, performance, security and mobility issues. To overcome this contrast, research on the Future Internet is exploring novel socalled content-centric architectures, where the network layer directly provides users with contents, instead of providing communication channels between hosts. In this paper, we identify the main functionalities of a content-centric network (CONET), we discuss pros and cons of literature proposals for an innovative, content-centric network layer and we draw our conclusions, stating some general requirements that, in our opinion, a CONET should satisfy.