On 25/07/2018 11:46, Tom Herbert wrote: > On Tue, Jul 24, 2018 at 3:54 PM, Templin (US), Fred L > <[email protected]> wrote: >> I have an observation that I would like to see addressed in the document. >> Some applications >> (e.g., 'iperf3' and others) actually leverage IP fragmentation to achieve >> higher data rates than >> are possible using smaller (but unfragmented) whole packets. >> >> Try it - by default, iperf3 sets an 8KB UDP packet size and allows packets >> to fragment across >> paths that support only smaller MTUs. I have seen iperf3 exercise IP >> reassembly at line rates >> on high-speed links, i.e., it shows that reassembly at high rates is >> feasible. >> >> We know from RFC4963 that there are dangers for reassembly at high rates, >> but there are >> applications such as iperf3 that ignore the "SHOULD NOT" and leverage IP >> fragmentation >> anyway. So, should the "SHOULD NOT" have an asterisk? >> > Fred, > > My reading of the draft is that IP fragmentation is fragile on the > open Internet and should be avoided for applications that run over the > Internet. That doesn't mean that fragmentation should be avoided in > all use cases. In particular, if fragmentation is used in a closed > network with low loss and has appropriate security measures in place, > then it can be beneficial. I suspect that describes the network that > your're running iperf in. If this interpretation of the draft's intent > is correct, maybe there could be some words to clarify that.
Those words are in RFC2119 already: >> 4. SHOULD NOT This phrase, or the phrase "NOT RECOMMENDED" mean that >> there may exist valid reasons in particular circumstances when the >> particular behavior is acceptable or even useful, but the full >> implications should be understood and the case carefully weighed >> before implementing any behavior described with this label. Brian > Tom > >> Thanks - Fred >> >>> -----Original Message----- >>> From: Int-area [mailto:[email protected]] On Behalf Of Wassim Haddad >>> Sent: Tuesday, July 24, 2018 12:43 PM >>> To: [email protected] <[email protected]> >>> Cc: [email protected] >>> Subject: [Int-area] WG Adoption Call: IP Fragmentation Considered Fragile >>> >>> Dear all, >>> >>> We would like to start a WG adoption call for >>> draft-bonica-intarea-frag-fragile (“IP Fragmentation Considered Fragile”). >>> >>> https://www.ietf.org/id/draft-bonica-intarea-frag-fragile-03.txt >>> >>> >>> Please indicate your preferences on the mailling list. The deadline is >>> August 10th. >>> >>> >>> Thanks, >>> >>> Juan & Wassim >>> _______________________________________________ >>> 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
