On Tue, May 5, 2015 at 10:53 AM, Joe Touch <to...@isi.edu> wrote: > > > On 5/5/2015 9:39 AM, Templin, Fred L wrote: >> Hi Joe, > .. >>> IP in UDP adds only port numbers and an Internet checksum. >>> >>> That doesn't address fragmentation; if outer fragmentation is assumed, >>> IPv4 needs to be rate-limited to avoid ID collisions and the Internet >>> checksum is insufficient to correct those collisions. >> >> Right - that is why we have GUE. But, when these functions are not >> needed GUE can perform header compression and the result looks >> exactly like IP in UDP. > > That seems impossible. > > The outer IP header indicates UDP as next-protocol, and GUE based on the > port number. > > You can't then compress the GUE header to nothing. You still need at > least one bit somewhere to indicate "compressed GUE header", and there's > nothing left. > As I described previously, the first two bits of GUE header are version number. If we reserve version 0x1, then an IPv6 or IPv4 can be directly encapsulated on the same port with GUE (version 0)-- this is what Fred means by GUE header compression. No new port is needed for this and it is backwards compatible with GUE.
> And no, I don't think "compressed GUE" qualifies as an independently > useful service that warrants a separate UDP port. > > Joe > > _______________________________________________ > nvo3 mailing list > nvo3@ietf.org > https://www.ietf.org/mailman/listinfo/nvo3 _______________________________________________ nvo3 mailing list nvo3@ietf.org https://www.ietf.org/mailman/listinfo/nvo3
