There is much confusion in the field, for many reasons.  A buzzword gets invented, and used as if it means something. Most people are baffled, and assume everyone else knows what it means. People who do think they know what it means have totally different ideas from each other about what it means. Another reason for confusion is hype.  Some ill-defined technology is advertised to be the solution to all problems.  And yet another reason is focusing on only one aspect of the system, such as the syntax of messages, or having provably secure cryptographic algorithms.  Some examples in this talk will be seemingly simple questions like why do we need both Ethernet and IP, or the difference between theory and practice when people browse the Internet using wonderful protocols with perfect cryptography.