Hi All, On Tue, 2002-11-12 at 09:25, Keith Moore wrote: <snip> > I actually think that all applications that expect to keep associations > around more than some well-known (and explicitly chosen) lifetime need > to have mechanisms for surviving renumbering. And unless/until > we introduce renumbering support into TCP, UDP, and SCTP, this means > providing that support in layer 7. >
Isn't this really the End-to-End argument, which I think pretty much summarises to "if you want something done properly, you've got to do it yourself". We are focusing on renumbering being an event that will disrupt TCP sessions, which obviously it will. But what about the interface failing that the operating system chose to use as the local end-point IP address for the TCP session ? Renumbering is a planned, managed and controlled event, interface failures obviously isn't. If the operating system makes an unfortunate choice of source IP address, by using an interface that is going to fail in the near future, the application's TCP sessions will fail. If that is unacceptable to the application, the application has the most interest in implementing mechanisms to reduce or avoid the impact of that failure. Are we trying to solve a problem at the network layer, which impacts the transport layer, which really is best and most appropriately solved at the application layer ? In the context of the End-to-End argument, could TCP/SCTP be seen to be a performance enhancement for the application, rather than trying to provide "perfect" reliability ? Should it really be "dumb network, smart hosts, wise applications" ? Regards, Mark. -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
