Hi Dan, Couldn't you get this out of sync already today?
You get a SIP message with application/sdp, and then the message body contains something else... Regards, Christer > -----Original Message----- > From: Dan Wing [mailto:[EMAIL PROTECTED] > Sent: 11. toukokuuta 2007 8:35 > To: Christer Holmberg (JO/LMF); 'Paul Kyzivat' > Cc: [EMAIL PROTECTED]; [email protected] > Subject: RE: [Sip] Support for Multipart/MIME > > > > > -----Original Message----- > > From: Christer Holmberg (JO/LMF) > > [mailto:[EMAIL PROTECTED] > > Sent: Thursday, May 10, 2007 9:13 PM > > To: Dan Wing; Paul Kyzivat > > Cc: [EMAIL PROTECTED]; [email protected] > > Subject: RE: [Sip] Support for Multipart/MIME > > > > > > Hi, > > > > >* if they're out of sync, which one takes precedence (that > is, do I > > >process a Content-Type that isn't listed in the > > >Content-Type-List?) > > > > The Content-Type contains "multipart/*", while the > Content-Type-List > > contains the types (app/sdp, app/isup, app/whatever etc) > within that > > multipart. > > > > Please note that I am talking about SIP headers, not in the MIME > > bodies (of course, if a MIME body contains another multipart/*, the > > header could perhaps also be used there). > > Let me clarify my point about that new Content-Type-List > header being out of sync with the body. Here is an example > -- a SIP header containing, among other things: > > From: ... > To: ... > Content-Type-List: application/sdp > Content-Type: multipart/mixed; boundary=B > > and the body contains: > > --B > Content-Type: application/sdp > Content-Disposition: session > > v=0 > ... > > --B > Content-Type: application/pidf+xml > > <?xml version="1.0" encoding="UTF-8"?> > <presence xmlns="urn:ietf:params:xml:ns:pidf" > ... > --B-- > > In such a situation, a device which supports > Content-Type-List in an effort to optimize its MIME parsing, > wouldn't know there is a "Content-Type: > application/pidf+xml" in the body. > > > > >* if a UA knew an intermediate box used Content-Type-List, the UA > > >could use Content-Type-List to make the intermediate box > think some > > >sort of Content-Type is not present. That additional content-type > > >might contain the secret of the universe, which the > intermediate box > > >really needed to know. > > > > Well, this depends on the functionality of the middle-box. > > > > If the middle-box is going to do some kind of policing, or > otherwise > > verify that the multipart actually contains what is claimed in the > > Content-Type-List, it will have to parse the multipart anyway. > > Right. > > Proxies are supposed to ignore the body, so what sort of > devices which aren't enforcing policy might benefit from the > Content-Type-List optimization? > > > >* looking for "^Content-Type *:" isn't too hard; you don't really > > >need to bother parsing MIME and looking for nested parts > unless there > > >is, in fact, a content-type you care about. Per Paul's > message, if > > >you only want ones with > > >Content-Disposition: session, you could look for that > string within > > >4-5 lines of Content-Type; if you found it, then you could > parse the > > >MIME in the body. > > > > I don't think it's that easy. Assume one MIME body contains a SIP > > message (or part of a SIP message), or any other protocol > which uses > > the Content-Type header, which is not the Content-Type > header of the > > MIME body itself. The same goes for Content-Disposition. > > Yes, there can of course be false-positives; the same sort of > false positives would occur with Content-Type-List: it could > list a content-type which is inside of a MIME part you > wouldn't otherwise process (due to the wrong > Content-Disposition, for example). > > -d > > > > Regards, > > > > Christer > > > > > > > > > > > > -----Original Message----- > > > > From: Christer Holmberg (JO/LMF) > > > > [mailto:[EMAIL PROTECTED] > > > > Sent: Thursday, May 10, 2007 6:44 PM > > > > To: Paul Kyzivat; Dan Wing > > > > Cc: [EMAIL PROTECTED]; [email protected] > > > > Subject: RE: [Sip] Support for Multipart/MIME > > > > > > > > > > > > Hi, > > > > > > > > The following is not a proposal, but more "brain storming". > > > > > > > > Would it be helpful to have a SIP header, e.g. > > > > Content-Type-List, which > > > > would list the different Content-Types in a multipart/* body. > > > > > > > > A node could then first check that header in order to see > > > whether the > > > > multipart/* contains something a specific node is > interested in - > > > > without having to parse the full multipart/* body > first. It could > > > > speed up the processing in nodes which may have interest > > only in a > > > > small set of Content-Types. > > > > > > > > Comments? > > > > > > > > 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
