Hi Brian, Hi Joel, the point of my mail was not to start a discussion about the examples I provided but to note that the suggested "let's reduce complexity by reducing options" is not as easy as it sounds in practice. In the context of the document Stephen wrote and the proposal that was made on the list I was wondering whether a bit more analysis about what the problems we are trying to solve would be helpful. As some folks had raised implementing specifications is not a sufficient condition for interoperability, or successful deployment. I personally believe that IETF working groups are a fine job in writing code along with their specification work. Ciao Hannes On Jan 23, 2013, at 9:58 AM, Brian E Carpenter wrote: > On 23/01/2013 04:14, joel jaeggli wrote: >> On 1/22/13 12:34 AM, Hannes Tschofenig wrote: >>> Another example from a different area: Why do we need so many >>> transition technologies for the migration from IPv4 to IPv6? Wouldn't >>> it be less complex to just have one transition mechanism? >> >> You mean no transition mechanisms... > > That was, in fact, the plan (dual stack during coexistence). > It went wrong. > > Brian