RFC 3297 (rfc3297) - Page 2 of 46

Content Negotiation for Messaging Services based on Email

RFC 3297      Content Negotiation for Messaging Services       July 2002


     2.3 Goals for content negotiation .............................. 8
   3. Framework for content negotiation..............................10
     3.1 Send data with an indication of alternatives ...............11
        3.1.1 Choice of default data format..........................12
        3.1.2 MDN request indicating alternate data formats..........12
        3.1.3 Information about alternative data formats.............13
     3.2 Receiver options ...........................................14
        3.2.1 Alternatives not recognized............................14
        3.2.2 Alternative not desired................................14
        3.2.3 Alternative preferred..................................14
     3.3 Send alternative message data ..............................16
     3.4 Confirm receipt of resent message data .....................17
   4. The Content-alternative header.................................18
   5. The Original-Message-ID message header.........................18
   6. MDN extension for alternative data.............................19
     6.1 Indicating readiness to send alternative data ..............19
     6.2 Indicating a preference for alternative data ...............20
     6.3 Indicating alternative data is no longer available .........21
     6.4 Indicating loss of original data ...........................22
     6.5 Automatic sending of MDN responses .........................22
   7. Internet Fax Considerations....................................22
   8. Examples.......................................................23
     8.1 Sending enhanced Internet Fax image ........................23
     8.2 Internet fax with initial data usable ......................27
     8.3 Negotiate to lower receiver capability .....................28
     8.4 Sending an alternative content type ........................32
   9. IANA Considerations............................................36
     9.1 New message headers ........................................36
     9.2 MDN extensions .............................................36
        9.2.1 Notification option 'Alternative-available'............36
        9.2.2 Notification option 'Alternative-not-available'........36
        9.2.3 Disposition modifier 'Alternative-preferred'...........37
        9.2.4 Disposition modifier 'Original-lost'...................37
   10. Internationalization considerations...........................37
   11. Security Considerations.......................................37
   12. Acknowledgements..............................................38
   13. References....................................................38
   Appendix A: Implementation issues.................................40
     A.1 Receiver state .............................................40
     A.2 Receiver buffering of message data .........................41
     A.3 Sender state ...............................................42
     A.4 Timeout of offer of alternatives ...........................42
     A.5 Timeout of receiver capabilities ...........................42
     A.6 Relationship to timely delivery ............................43
     A.7 Ephemeral capabilities .....................................43
     A.8 Situations where MDNs must not be auto-generated ...........44
   Appendix B: Candidates for further enhancements...................44
   Authors' Addresses................................................45



Klyne, et. al.              Standards Track