The SDP Directorate

Introduction and background

During the past years the Session Description Protocol (SDP: RFC 4566 and its successors) has become a ubiquitous protocol being used in a number of different applications where one or more endpoints need to describe one or more media streams. SDP has been developed throughout the years in the MMUSIC working group of the IETF.

Many of the applications using SDP have had requirements that have led to the creation of extensions to the SDP core protocol. RFC 4566 Section 8 describes the procedure for creating and registering such extensions. Some of the current extensions have been created within the MMUSIC WG while others have been created in other IETF working groups or even outside the IETF. In order to ensure that future extensions developed outside the MMUSIC WG have the advantage of review by experts that have encountered SDP issues and have repeated experience with applying generic solutions to particular problems, the ART ADs have created an SDP directorate.

Directorates are defined in RFC 2418:

In many areas, the Area Directors have formed an advisory group or directorate.  These comprise experienced members of the IETF and the technical community represented by the area.  The specific name and the details of the role for each group differ from area to area, but the primary intent is that these groups assist the Area Director(s), e.g., with the review of specifications produced in the area.

Objective

It is the goal of the SDP directorate to watch over the creation of extensions to SDP, in particular those created outside the MMUSIC working group in the IETF. The SDP directorate acts as a consultative group of experts offering expertise and guidelines to developers of extensions to SDP.

Operative aspects

  • Documents that extend or modify SDP, or register parameters or new values of parameters used within SDP, are candidates for review by the SDP directorate. The reviews are typically requested by the document's authors, shepherd, or responsible ART AD.

  • Reviews are requested by contacting the SDP directorate coordinators (currently the MMUSIC chairs). Reviews are typically requested as soon as the document to be reviewed is stable enough.

  • The reviews conducted by members of the SDP directorate will be published to the MMUSIC mailing list and to the authors within a reasonable period, typically no more than two weeks, so that the MMUSIC WG can become aware and provide input to the review. Complex documents may take additional time than two weeks. If a review is expected to take more than three weeks, the SDP directorate coordinators will inform about it at the beginning of the review.

  • The ART ADs appoint members of the SDP directorate. The MMUSIC co-chairs act as co-chairs of the directorate as well as coordinators, receiving review requests from shepherds, allocating a member to conduct the review in the agreed timeline, assuring that reviews are posted to the MMUSIC list and the authors, and mediating in conflict situations.

Current list of members of the SDP directorate

The list of members of the SDP directorate includes the MMUSIC WG chairs and currently also the following individuals:

  • Ali Begen
  • Christer Holmberg
  • Dan Wing
  • Paul Kyzivat
  • Jonathan Lennox  

Form of review

Each review should include the following at the beginning of the review to clarify the intent of the review for the document editor/authors:

  • For Early reviews (typical):

I am the assigned SDP directorate reviewer for draft-FOOBAR.txt.

For background on the SDP directorate, please see the FAQ at <http://www.ietf.org/iesg/directorate/sdp.html>.

Please resolve these comments along with any other comments you may receive.

  • For WG Last Call reviews (typical):

I am the assigned SDP directorate reviewer for draft-FOOBAR.txt.

For background on SDP directorate, please see the FAQ at <http://www.ietf.org/iesg/directorate/sdp.html>.

Please resolve these comments along with any other Last Call comments you may receive.

  • For post-WGLC reviews (less typical):

I am the assigned SDP directorate reviewer for draft-FOOBAR.txt.

For background on SDP directorate, please see the FAQ at <http://www.ietf.org/iesg/directorate/sdp.html>.

Please wait for direction from your document shepherd or AD before posting a new version of the draft.

Each review will clearly summarize whether or not there are SDP issues in the document that need to
be addressed, or if the issues are severe enough that an entirely different approach should be considered,
or that further work is not recommended.

In addition to the general SDP design guidelines that follow from RFC 4566, the review should consider the following WG and/or topic specific guidelines as appropriate:

  • [RFC4288] Media Type Specifications and Registration Procedures
  • [RFC3424] IAB Considerations for Unilateral Self-Address Fixing (UNSAF) Across Network Address Translation
  • [RFC4924] Reflections on Internet Transparency