What Happened to IPv5?

You are probably familiar with the fact that IPv4 is more or less the standard that the Internet and networks of the world rely on. IPv6 is the emerging standard developed to expand the available pool of addresses as well as addressing a variety of performance and security issues in IPv4. So, why did we never hear of any IPv5 equipment? Do they just count by 2’s when they are creating IP standards? Apparently not. Network expert Silvia Hagen addresses the issue of the missing IP standard in answering the question “Why wasn’t there an IPv5?”