Hi Lucy, > -----Original Message----- > From: Lucy yong [mailto:[email protected]] > Sent: Wednesday, April 29, 2015 11:48 AM > To: Templin, Fred L; Tom Herbert > Cc: [email protected]; [email protected] > Subject: RE: [Int-area] Why combine IP-in-UDP with GUE? > > > > > Change the GUE header to treat the first nibble as a next header selector. > > 4 means IPv4, 6 means IPv6 and X means GUE. > > [Lucy] As I mentioned in several previous mails, I don't think that > > this is a good design for GUE. Even if a compression is required, the > > solution SHOULD use a separate UDP port to indicate IP first and then check > > the first nibble for IPv4 or IPv6, which, in fact, is the IP- > in- UDP proposal. > > I will say again that the IP-in-UDP proposal as it stands does not have a > solution for tunnel fragmentation (made available by GUE). > [Lucy] That is true. The IP-in-UDP proposal applies the case where no > fragmentation at tunnel end point is needed. GUE can deal with > it.
Existing tunnel protocols (IP*-in-IP*) are deficient in not providing a tunnel fragmentation mechanism per Section 3.1.7 of RFC2764. > > However I agree with Tom that the compression concept does not align > > with GUE principal. GUE encapsulation should not assume IP payload in first > > place! > > The proposed solution does not assume IP; it assumes a next header selector > in the first nibble of the data following the UDP header. > Non IP can be conveyed when the next header selector indicates GUE. > [Lucy] the first nibble is intended for indicating version of IP, not for a > next header selector. Forcing other protocol to follow this > assumption is bad. Please read RFC4928. There are many cases that GUE > payload is IP or other and GUE header is required. The first > nibble design splits majority from a corner case as first logic, which is a > bad design. The "compression" version does not have the same > tunnel property as GUE based tunnel, we should not mix them at design level. I disagree with "bad", and I do not think RFC4928 is applicable when the first nibble appears within a UDP encapsulation for which there is a specific user of that UDP port number. ECMP classifications in the network would not reach deeply into a UDP encapsulation in order to inspect bits specific to that UDP port. Thanks - Fred [email protected] > Lucy > > Thanks - Fred > [email protected] > > > Regards, > > Lucy > > > > > > > > Thanks - Fred > > [email protected] > > > > > Tom > > > > > > > Thanks - Fred > > > > [email protected] > > > > > > > >> Tom > > > >> > > > >> > Thanks - Fred > > > >> > [email protected] > > > >> > > > > >> >> Lucy > > > >> >> > > > >> >> Thanks - Fred > > > >> >> [email protected] > > > >> >> > > > >> >> > However, if GUE payload is > > > >> >> > IP, it is OK to inspect the first nibble of the payload to > > > >> >> > determine IPv4 or IPv6 because this aligns with IP protocol. > > > >> >> > > > > >> >> > Thanks, > > > >> >> > Lucy > > > >> >> > > > > >> >> > - Stewart > > > >> >> > > > > >> >> > > > > >> >> > > > > >> >> > _______________________________________________ > > > >> >> > Int-area mailing list > > > >> >> > [email protected] > > > >> >> > https://www.ietf.org/mailman/listinfo/int-area > > > >> >> > > > > >> >> > _______________________________________________ > > > >> >> > Int-area mailing list > > > >> >> > [email protected] > > > >> >> > https://www.ietf.org/mailman/listinfo/int-area > > > >> > > > > >> > _______________________________________________ > > > >> > Int-area mailing list > > > >> > [email protected] > > > >> > https://www.ietf.org/mailman/listinfo/int-area _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
