Hi, >>My main concern is not what wording (SHALL, MUST, etc) we use. >> >>The issue is that I think we need text saying what implementations >>that DO NOT support alternative and/or nested shall do. If we say that
>>they shall reject the message I believe that many of the existing >>implementations will be compliant with the spec. >> >>And, if we give the possibility to simply reject the message, I >>believe it will be easier to get people to change their >>implementations, if they currently simply discard alternative and/or nested today. > >I agree that simply ignoring a body can cause huge problems. > >I believe we have addressed that by clarifying the use of >Content-Disposition and its handling parameter. In the >absence of handling=optional, the request must be rejected. >This part must be of MUST strength. And the default of >handling=required in the absence of a C-D header must also be >of MUST strength. I agree with that. But, if there are implementations that don't even look at the C-D headers, because they discard the whole message body because they don't support multipart/alternative, that does not solve the problem. So, it is important that implementations either treat alternative as mixed or, as I suggest, reject the request. BTW, in the case of alternative, is the receiver required to support all body types if they have handling=required? Or, is it enough if they support at least one of the alternative body types? >But there is little we can do about existing implementations >that don't do that right. I guess I can see writing up >somewhere that even if you aren't going to make your >implementation compliant to this full draft you should at >least do make sure you support Content-Disposition. Would it >be helpful in that regard to make that part a separate draft??? I absolutely agree that implementations MUST support C-D (including the default value if C-D is not present). Regards, Christer > >> -----Original Message----- > >> From: Gonzalo Camarillo [mailto:[EMAIL PROTECTED] > >> Sent: 29. toukokuuta 2007 16:06 > >> To: Paul Kyzivat > >> Cc: Christer Holmberg (JO/LMF); [email protected] > >> Subject: Re: [Sip] MIME: Nested bodies with option-tag? > >> > >> Hi, > >> > >> what I am hearing is that there are implementations out there that > >> support multipart but not nested. Therefore, we need to decide two > >> things: > >> > >> 1) do we want to have a MUST for multipart and a SHOULD > for nested? I > >> would say that we should have the same level (e.g., MUST, if we > >> decided that MUST is appropriate) for both. > >> > >> 2) do we need a way for implementations that support multipart but > >> not nested to be quickly updated to, at least, report that > fact with > >> an error response? This may make sense. > >> > >> Cheers, > >> > >> Gonzalo > >> > >> Paul Kyzivat wrote: > >>> More or less repeating what I said before: > >>> > >>> I expect we do have to account in some way for > implementations that > >>> have already been deployed, in absence of a clarifying document. > >>> Exactly how we deal with that is still TBD. > >>> > >>> But as we define what is required to support this in the > future, I > >>> think there is *no* benefit to defining two levels of > >> support - full > >>> and partial. Anybody that sets out to provide support for this > >>> document should be expected to do it all - its not that > much harder. > >>> > >>> Paul > >>> > >>> Christer Holmberg (JO/LMF) wrote: > >>>> Hi, > >>>>> I wonder whether we should define an option-tag for the > >> support of > >>>>> nested bodies. > >>>>> > >>>>> I don't think there's a lot to be gained from defining such an > >>>>> option-tag. The sender should already be aware that > >> there is a risk > >>>>> the recipient can't understand nested bodies, and have > >> arranged for > >>>>> suitable fallbacks. Conversely, the recipient should (at > >> least) be > >>>>> able to skip the nested multipart body part in the proper > >> "I don't > >>>>> understand this body part" way. All an option-tag would > >> do is allow > >>>>> the sender to not add a fallback. > >>>> In that case we need some specific text saying that if the > >> receiver > >>>> does not support nested multiparts it MUST do-this-and-do-that. > >>>> > >>>> Because, as I said earlier, I don't think we will > achieve what we > >>>> want by saying that one MUST be able to parse nested > >> multiparts. It > >>>> can be rather tricky to implement (depending on how the > parser is > >>>> implemented, though), and since there aren't really any > >> use-cases out > >>>> there yet I am pretty sure some people will choose not to > >> implement > >>>> it (and saying that people are not compliant in that > case will not > >>>> really help from an interop perspective). So, because of > >> that I think > >>>> it would be good not to mandate the support of nested > >> multiparts, but > >>>> to mandate appropriate behavior if not supported - just > >> like in any > >>>> other case when a MIME body contains an unsupported but > >> required content type. > >>>> Regards, > >>>> > >>>> Christer > >>>> > >>>> > >>>> > >>>>> Sip mailing list https://www1.ietf.org/mailman/listinfo/sip > >>>>> This list is for NEW development of the core SIP Protocol Use > >>>>> [EMAIL PROTECTED] for questions on > current sip Use > >>>>> [EMAIL PROTECTED] for new developments on the application of sip > >>>>> > >>>> > >>>> _______________________________________________ > >>>> Sip mailing list https://www1.ietf.org/mailman/listinfo/sip > >>>> This list is for NEW development of the core SIP Protocol Use > >>>> [EMAIL PROTECTED] for questions on > current sip Use > >>>> [EMAIL PROTECTED] for new developments on the application of sip > >>>> > >>> > >>> _______________________________________________ > >>> Sip mailing list https://www1.ietf.org/mailman/listinfo/sip > >>> This list is for NEW development of the core SIP Protocol Use > >>> [EMAIL PROTECTED] for questions on current sip Use > >>> [EMAIL PROTECTED] for new developments on the application of sip > >>> > >> > > > _______________________________________________ Sip mailing list https://www1.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
