Hi Brian, > -----Original Message----- > From: Brian E Carpenter [mailto:[email protected]] > Sent: Friday, June 28, 2013 9:20 PM > To: Templin, Fred L > Cc: james woodyatt; 6man > Subject: Re: New Version Notification for draft-bonica-6man-frag- > deprecate-00.txt > > On one point... > > > On 29/06/2013 10:44, Templin, Fred L wrote: > ... > >> and (b) accepting that strapping the MTU at 1280 is > >> a reasonable short term policy. If (a) progressively pervades > >> the installed base then (b) can be dropped as the years go by. > > > > Once a link sets a 1280 MTU, how will it know that it is now > > safe to increase the MTU? And, once set, how can we expect > > operators to go back and re-set in the future. IMHO, strapping > > the MTU to 1280 everywhere now would become ossified long into > > the future. > > It would certainly take years, but I think the end result would be > implementors raising the default to the real link MTU, one stack > at a time. I don't think you find many IPv4 stacks today with > the MTU set low by default.
The transition anticipated by SEAL is as follows. Packets that are no larger than 1500 bytes are unconditionally accommodated with fragmentation/reassembly used if necessary. Hosts will then notice that they can get better performance by sending packets that are larger than 1500, and will use RFC4821 to ensure that those larger packets are getting through. The Internet will then naturally gravitate toward larger packets, and eventually the Internet "cell size" will bump up from 1500 to 8KB. Thanks - Fred [email protected] > Brian -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
