Re- Thanks, Michael. The proposed change is now implemented in our local copy. It can be tracked at https://tinyurl.com/8782bis-latest. Cheers, Med > -----Message d'origine----- > De : Michael Tuexen [mailto:tuexen@xxxxxxxxxxxxxx] > Envoyé : lundi 22 mars 2021 10:53 > À : BOUCADAIR Mohamed TGI/OLN > <mohamed.boucadair@xxxxxxxxxx> > Cc : tsv-art@xxxxxxxx; dots@xxxxxxxx; draft-ietf-dots-rfc8782- > bis.all@xxxxxxxx; last-call@xxxxxxxx > Objet : Re: Tsvart last call review of draft-ietf-dots-rfc8782-bis-05 > > > On 22. Mar 2021, at 10:31, <mohamed.boucadair@xxxxxxxxxx> > <mohamed.boucadair@xxxxxxxxxx> wrote: > > > > Re-, > > > > Please see inline. > > > > Cheers, > > Med > > > >> -----Message d'origine----- > >> De : tuexen@xxxxxxxxxxxxxx [mailto:tuexen@xxxxxxxxxxxxxx] > >> Envoyé : lundi 22 mars 2021 10:04 > >> À : BOUCADAIR Mohamed TGI/OLN > >> <mohamed.boucadair@xxxxxxxxxx> > >> Cc : tsv-art@xxxxxxxx; dots@xxxxxxxx; draft-ietf-dots-rfc8782- > >> bis.all@xxxxxxxx; last-call@xxxxxxxx > >> Objet : Re: Tsvart last call review of draft-ietf-dots-rfc8782-bis-05 > >> > >>> On 22. Mar 2021, at 07:42, <mohamed.boucadair@xxxxxxxxxx> > >> <mohamed.boucadair@xxxxxxxxxx> wrote: > >>> > >>> Hi Michael, > >>> > >>> Thank you for the review. > >>> > >>> The motivation was used as it was the key element in the > discussion > >> in Section 3.3.3 of RFC1122, but you made a fair comment. > >>> > >>> == > >>> DISCUSSION: > >>> Picking the correct datagram size to use when sending data > >>> is a complex topic [IP:9]. > >>> > >>> (a) In general, no host is required to accept an IP > >>> datagram larger than 576 bytes (including header and > >>> data), so a host must not send a larger datagram > >>> without explicit knowledge or prior arrangement with > >>> the destination host. > >>> == > >>> > >>> We can update the text as follows: > >>> > >>> OLD: > >>> assume a PMTU of 576 bytes for IPv4 datagrams, as every IPv4 > host > >>> must be capable of receiving a packet whose length is equal to > 576 > >>> bytes as discussed in [RFC0791] and [RFC1122]. > >>> > >>> NEW: > >>> assume a PMTU of 576 bytes for IPv4 datagrams (see Section 3.3.3 > >> of [RFC1122]). > >> Hi Med, > >> > >> let me try to get my point clear: > >> > >> You can use Section 3.3.3 of [RFC1122] to motivate that the sender > >> should > >> not send datagram larger than 576, since there is no guarantee that > the > >> receiver has resources to reassemble and process it. But RFC 1122 > >> makes > >> no statement about the path. > > > > [Med] There is this text in RFC1122: > > > > Since nearly all networks in the Internet currently > > support an MTU of 576 or greater, we strongly recommend > > the use of 576 for datagrams sent to non-local networks. > OK. Then I' fine with your proposed text. > Please note that this is a statement from 1989. It is fine if you can live > with that number, I would > guess that such a number is larger today (at least in the context of > WebRTC a number in the order of > 1200 bytes was used). > > Best regards > Michael > > > > As far as I know there is no safe value > >> for > >> a PMTU you can derive from a specification. > >> > > > > [Med] I agree with you. Things are more clear for IPv6. > > > >> > >> So maybe: > >> NEW: > >> assume a PMTU of 576 bytes for IPv4 datagrams (see Section 3.3.3 > of > >> [RFC1122] > >> for support at the receiver). > >> > >> Best regards > >> Michael > >>> > >>> Cheers, > >>> Med > >>> > >>>> -----Message d'origine----- > >>>> De : Michael Tüxen via Datatracker [mailto:noreply@xxxxxxxx] > >>>> Envoyé : lundi 22 mars 2021 00:33 > >>>> À : tsv-art@xxxxxxxx > >>>> Cc : dots@xxxxxxxx; draft-ietf-dots-rfc8782-bis.all@xxxxxxxx; last- > >>>> call@xxxxxxxx > >>>> Objet : Tsvart last call review of draft-ietf-dots-rfc8782-bis-05 > >>>> > >>>> Reviewer: Michael Tüxen > >>>> Review result: Ready with Nits > >>>> > >>>> This document has been reviewed as part of the transport area > >> review > >>>> team's ongoing effort to review key IETF documents. These > >> comments > >>>> were written primarily for the transport area directors, but are > >> copied > >>>> to the document's authors and WG to allow them to address any > >>>> issues raised and also to the IETF discussion list for information. > >>>> > >>>> When done at the time of IETF Last Call, the authors should > >> consider > >>>> this review as part of the last-call comments they receive. Please > >>>> always CC tsv-art@xxxxxxxx if you reply to or forward this review. > >>>> > >>>>> From a transport perspective, there is one minor issue: > >>>> Section 7.3 provides a motivation for using a path MTU for IPv4 of > >> 576 > >>>> bytes. > >>>> The motivation refers to the requirement that a receiver is > capable > >> of > >>>> receiving IPv4 packets of that size, however they can be received > >>>> fragmented. > >>>> While it is acceptable to use 576 bytes as the minimum PMTU, > the > >>>> motivation does not hold. _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. 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