Internet Engineering Task Force                                   SIP WG
Internet Draft                                              G. Camarillo
                                                                Ericsson
draft-camarillo-sip-parameter-registry-01.txt
June 17, 2003
Expires: December 2003


        The Internet Assigned Number Authority Header Field
       Parameter Registry for the Session Initiation Protocol

STATUS OF THIS MEMO

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

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Abstract

   This document creates an IANA registry for SIP header field
   parameters. It also lists the already existing parameters to be used
   as initial values for that registry.














G. Camarillo                                                  [Page 1]


Internet Draft                    SIP                      June 17, 2003





                           Table of Contents



   1          Introduction ........................................    3
   2          Use of the Registry .................................    3
   3          IANA Considerations .................................    3
   3.1        Header Field Parameters Sub-Registry ................    3
   4          Security Considerations .............................    4
   5          Acknowledgements ....................................    4
   6          Authors' Addresses ..................................    4
   7          Normative References ................................    5




































G. Camarillo                                                  [Page 2]


Internet Draft                    SIP                      June 17, 2003


1 Introduction

   RFC3261 [1] allows new header field parameters to be defined.
   However, RFC3261 omitted an IANA registry for them. This document
   creates such a registry.

2 Use of the Registry

   Both RFC defined and proprietary header field parameters MUST be
   registered with IANA as described below.

        Note that this includes header field parameters for P-
        headers.

3 IANA Considerations

   Section 27 of RFC 3261 [1] creates an IANA registry for method names,
   header field names, warning codes, status codes, and option tags.
   This specification instructs the IANA to create two a new sub-
   registry under http://www.iana.org/assignments/sip-parameters:

        o Header Field Parameters

3.1 Header Field Parameters Sub-Registry

   The majority of the SIP header fields can be extended by defining new
   parameters. New SIP header field parameters are registered by the
   IANA. When registering a new parameter for a header field, the
   following information MUST be provided.

        o Header field in which the parameter can appear.

        o Name of the parameter.

        o For proprietary parameters, a brief description of its
          semantics.

        o A reference to a further description, if available. For
          example, (in order of preference) an RFC, a published paper, a
          patent filing, a technical report, documented source code or a
          computer manual.

        o For proprietary parameters, contact information (postal and
          email address).

   Parameters that can appear in different header fields MAY have the
   same name. However, parameters that can appear in the same header
   field MUST have different names.



G. Camarillo                                                  [Page 3]


Internet Draft                    SIP                      June 17, 2003


   Table 1 contains the initial values for this sub-registry.


 Header Field                   Parameter Name   Description   Reference
 ________________________________________________________________________
 Accept                         q                              RFC 3261
 Accept-Encoding                q                              RFC 3261
 Accept-Language                q                              RFC 3261
 Call-Info                      purpose                        RFC 3261
 Contact                        expires                        RFC 3261
 Contact                        q                              RFC 3261
 Content-Disposition            handling                       RFC 3261
 From                           tag                            RFC 3261
 P-Charging-Function-Addresses  ccf                            RFC 3455
 P-Charging-Function-Addresses  ecf                            RFC 3455
 P-Charging-Vector              icid-value                     RFC 3455
 P-Charging-Vector              icid-generated-at              RFC 3455
 P-Charging-Vector              orig-ioi                       RFC 3455
 P-Charging-Vector              term-ioi                       RFC 3455
 Retry-After                    duration                       RFC 3261
 To                             tag                            RFC 3261
 Via                            branch                         RFC 3261
 Via                            comp                           RFC 3486
 Via                            maddr                          RFC 3261
 Via                            received                       RFC 3261
 Via                            rport                       [symmetric]
 Via                            ttl                            RFC 3261


   Table 1: IANA SIP header field parameter sub-registry


4 Security Considerations

   There are no security considerations associated to this document.

5 Acknowledgements

   Jonathan Rosenberg, Henning Schulzrinne, Rohan Mahy and Dean Willis
   provided useful comments.

6 Authors' Addresses

   Gonzalo Camarillo
   Ericsson
   Advanced Signalling Research Lab.
   FIN-02420 Jorvas
   Finland
   electronic mail:  Gonzalo.Camarillo@ericsson.com


G. Camarillo                                                  [Page 4]


Internet Draft                    SIP                      June 17, 2003


7 Normative References

   [1] J. Rosenberg, H. Schulzrinne, G. Camarillo, A. R. Johnston, J.
   Peterson, R. Sparks, M. Handley, and E. Schooler, "SIP: session
   initiation protocol," RFC 3261, Internet Engineering Task Force, June
   2002.





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G. Camarillo                                                  [Page 5]


Internet Draft                    SIP                      June 17, 2003


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G. Camarillo                                                  [Page 6]