--On Wednesday, 04 July, 2007 11:50 +0100 michael.dillon@xxxxxx wrote: >> So, what lesson(s) ought the IETF to take away from the fact >> that people aren't? > > That MPLS with 6PE is a superior migration scenario. > Or perhaps, that defining migration scenarios without the full > involvement of network operations people is an exercise in > futility. >... Michael, If the lesson we have learned is that the only practical way to handle and route IP (whether v4, v6, or otherwise) requires the use of an underlying virtual circuit layer, then much of what we are doing in the IETF involves an architectural delusion about the fundamental datagram and packet model of the Internet. Some applications work is insensitive to that delusion, others are not, but, if the circuit underlayer is really necessary, then much of TCP/IP represents unneeded complexity and we should be working to dispense with it. Despite the views of some "network operations people" (many, but perhaps not all of them with their feet stuck in legacy telco thinking), many of us still believe that datagram networks have significant value for more than multiplexing circuits. To us -- including people who have been involved in network operations -- it may make sense to optimize parts of networks with a single policy environment by the use of underlying circuit technologies. But, like classic CSMA/CD Ethernet, they are technologies that may be entirely appropriate in a restricted network environment but not for a global Internet, even if the global Internet interconnects several networks using such technology. Maybe we are all deluded and that, as has occasionally been claimed by some telco-based bodies, datagram networks are only useful for research and the future, as well as the past, of "real" networks lies in end-to-end circuits. But I'm not convinced yet. john _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf