Hi David, Thanks for the suggested text. It will be incorporated in the next revision.
Concerning your last question, the following sentence in 3.5 indicates that MTU discovery is the TS's responsability: "The interface MTU as seen by a Tenant System SHOULD be adjusted such that no fragmentation is needed. This can be achieved by configuration or be discovered dynamically." Marc > -----Original Message----- > From: nvo3 [mailto:[email protected]] On Behalf Of Black, David > Sent: Wednesday, May 21, 2014 6:14 PM > To: [email protected] > Subject: [nvo3] Dataplane requirements draft - section 3.5 - > path MTU text > > Turning to the dataplane requirements draft, here's proposed > elaboration text for the path MTU material in section 3.5 (no > change to the second and third bullet items - they're > included for completeness): > > OLD > Either of the following options MUST be supported: > > o Classical ICMP-based MTU Path Discovery [RFC1191] > [RFC1981] or > Extended MTU Path Discovery techniques such as defined in > [RFC4821] > > o Segmentation and reassembly support from the overlay layer > operations without relying on the Tenant Systems > to know about > the end-to-end MTU > > o The underlay network MAY be designed in such a > way that the MTU > can accommodate the extra tunnel overhead. > NEW > At least one of the following options MUST be supported: > > o Classical ICMP-based MTU Path Discovery [RFC1191] > [RFC1981] or > Extended MTU Path Discovery techniques such as defined in > [RFC4821]. Both techniques are based on use of > probe packets. > Classical MTU Path Discovery requires ICMP > responses from > the underlay network. Extended MTU Path > Discovery requires > detection of probe packet loss at the receiver > and means to > communicate that loss to the sender. > > o Segmentation and reassembly support from the overlay layer > operations without relying on the Tenant Systems > to know about > the end-to-end MTU > > o The underlay network MAY be designed in such a > way that the MTU > can accommodate the extra tunnel overhead. > > ------------------------------ > > There's an additional question - what does that initial > "MUST" ("At least one of the following options MUST be > supported:") apply to?? > > The framework draft text on this topic describes Tenant > Systems using MTU discovery techniques, whereas some of the > options above apply to the nvo3 dataplane (e.g., overlay > segmentation and reassembly could reside in NVEs). > > > Thanks, > --David > ---------------------------------------------------- > David L. Black, Distinguished Engineer > EMC Corporation, 176 South St., Hopkinton, MA 01748 > +1 (508) 293-7953 FAX: +1 (508) 293-7786 > [email protected] Mobile: +1 (978) 394-7754 > ---------------------------------------------------- > > _______________________________________________ > nvo3 mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/nvo3 > _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
