Computer users often share and procure resources over the Internet. Unfortunately, the construction philosophy  and design  of today’s global computer network focuses on the use of addresses and the transmission control protocol (TCP) to exchange data and share resources among host machines. Arguing that users care about having content accessible via the Internet and not the locations of the host machines, Jacobson et al. suggest content-centric networking (CCN) for content-based packet transmission.
CCN consists of two types of packets. The customer uses an interest packet to request a resource from any reachable interface on the Internet. Any node that receives the request and has data that fulfills the query can reply with a data packet. CCN uses content names to connect interest and data packets, which enables multiple nodes to share broadcasts of identical content over a transmission medium. CCN looks up the name of each arriving packet at a node and performs the appropriate action. As the authors explain, “the core CCN packet forwarding engine has three main data structures”: a list of outgoing nodes supports the querying of multiple data sources in parallel; a buffer memory of the arriving data packets exploits the probability of data sharing, which reduces downstream delay and the demand for upstream bandwidth; and a table tracks the interests dispatched upstream toward content sources to enable the return of data downstream to requesting nodes. CCN maintains local communication and a flow balance of packets at each hop.
The authors discuss the implementation of and performance results from a prototype CCN system. The prototype system’s data transfer efficiency was analogous to that of TCP. It remained constantly effective in distributing multiple copies of a large data file over a network. Voice over Internet protocol (VoIP) on top of the prototype system showed no packet lost due to link connection failures.
The CCN paradigm represents a remarkable call for a shift away from the traditional TCP/IP. CCN is different from the traditional IP in its optimal strategic choice among alternative multiple connections in the dynamic Internet environment. The authors cleverly design a content-based security system to replace the IP network stack. The system offers the protection of and trust in the content for retrieval over the Internet. In the model, private content can be encrypted and all content is digitally signed. Moreover, all routing and policy information can be authenticated to help combat network attacks such as spoofing, flooding, and tampering. With today’s ever-increasing activities over social Web sites, the content distribution effectiveness of CCN is valuable.