Content identification in PI-CAN network Mateusz Nowak * , Sławomir Nowak * , Piotr Pecka * , Krzysztof Grochla * , * Institute of Theoretical and Applied Informatics, ul. Bałtycka 5, 44-100 Gliwice, Poland {m.nowak, emanuel, piotr, kgrochla}@iitis.pl Abstract. Content addressing is one of the basic issues while design of CAN architecture and solution. The paper is devoted to the problem of choice of identifier format, length and characteristic. Basic assumptions of CAN as one of Parallel Internets in IIP project are presents and requirements for content identifier are shown in this context. Discussion of possible solutions is presented and proposal of final identifier format is provided. Keywords: CAN, content aware networks, Future Internet Engineering 1 Introduction The significant increase of different kind of media content that is available in the Internet led to the concept of a CAN (Content Addressable Networks or Content Aware Networks), are also known as CCN (Content Centric Networks) [2],[7]. These networks use the new paradigm of “content -centric network” as opposed to used in the current TCP/IP networks “host -centric” paradigm. Traditional networking architectures concentrate on the problem of providing a connection between terminals and hosts, while users are typically interested in reaching a particular destination object (content). When the user request delivery of a file using HTTP protocol, a particular file is identified by URL, containing host address and file name within this host. When the file is moved from host to host, determining the location of the requested object becomes a problem. A broken web link is a common problem in such a case. The problem is solved by introducing the less location dependent addressing schemes (e.g. URL), however, these solutions are not always sufficient (for example, do not support possible replication of the same content). In CAN the user requests a particular file, while the network layer is responsible for its location and the transmission. CAN networks treat the searching, identification (content resolution) and delivery of content as the base functionality. The content in the CAN network is uniquely identified by an identifier, which consequently acts as a user level address. The CAN network requires developing a new architecture that supports content searching, content localization (resolution), and content delivery with respect to