Four Internets

Communications of the ACM 

The vision of an open Internet is characteristic of Silicon Valley's tech pioneers. The free and efficient flow of packets of bits requires decentralization to prevent bottlenecks occurring at the central points as the system scales, open standards to allow interoperability, and IP addresses to identify the correct destination. We take this system for granted, but one does not need a very long memory to recall a time when IT was dominated by proprietary protocols like AppleTalk or DECnet, and when one could not easily send an email message from AOL to Prodigy. Yet the Internet has not simply improved--it has evolved into an open system as a result of philosophical and political decisions, as well as technical ones.2,5 In a recent Communications "Cerf's Up" column, Vinton Cerf argued there is a fundamental division between the IP layer and the application layers of the Internet, which together function to keep the open Internet flowing, and what he called the "virtual political layer," higher in the stack where the content is consumed and judged.