Hi Lucy, > -----Original Message----- > From: Joe Touch [mailto:[email protected]] > Sent: Tuesday, April 28, 2015 11:29 AM > To: Lucy yong; Templin, Fred L; Tom Herbert > Cc: [email protected] > Subject: Re: [Int-area] Why combine IP-in-UDP with GUE? > > > > On 4/28/2015 11:24 AM, Lucy yong wrote: > > Hi Fred, > > > > GUE uses UDP port to indicate GUE encapsulation as UDP payload and > > GUE has prototype field to indicate the payload type. Making an > > exception and requiring inspection of first nibble at end points is > > not a good idea.
Yes, GUE has an officially assigned UDP port number (same as AERO). That does not mean that a combined IP-in-UDP and GUE approach could not use that same (single) port number nor a (pseudo) version field in the first four bits following the UDP header. Think of IP-in-UDP as simply GUE with header compression. Thanks - Fred [email protected] > > I don't like the combination approach. > > If you examine the first 4-bits of the IP field, you will: > > - work with any IP version in the future > - no need new GUE codepoints for new IP versions > > If you keep duplicate information in the header, you will: > > - need to explain what you do when the two fields > do not match > > - still need to check the first 4 bits of the IP > header anyway > > - still need to check some bits in the GUE header > > There's no downside to using the existing IP version field here, and > there are many downsides to using a duplicate field. > > Joe _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
