Document: draft-munakata-sip-privacy-guideline-03.txt
Reviewer: David L. Black
Review Date: 3 August 2008
IETF LC End Date: 7 August 2008

Summary:

This draft is on the right track, but has open issues, described in the review.

Comments:

The draft is in very good shape - it does a good job of explaining the requirements for what is and is not to be done and why.  Significant care has been taken to avoid modifying the RFCs that define the SIP privacy features.

The first open issue is that this draft is currently intended to be an Informational RFC - the responsible AD should recheck whether Standards Track (Proposed Standard RFC) would be more appropriate.
The draft uses RFC 2119 upper-case requirements language (e.g., MUST, SHOULD), only when restating requirements from other standards track RFCs, but there appear to be a number of lower-case requirement statements (e.g., for the SDP header lines in Section 5.2) that appear to merit RFC 2119 language.  If the draft becomes standards track in order to do this, the Note in Section 2 about use of RFC 2119 terminology would need to be modified appropriately.

The second open issue is in Section 5.3.3.  I think what is being stated in this section is that privacy requirements will cause the Replaces header and "replaces" parameter to not work in some situations, and this loss of functionality is allowed and/or intended (i.e., it is not the responsibility of a privacy service to ensure that these features always work).  That should be stated explicitly, in a form that tells implementers that having these not work because of privacy is acceptable.

If I did not understand the section correctly, the text needs clarification.

Nit: In Section 5.1.4:

   The recommended form of the From header for anonymity is:

   From: "Anonymous" <sip:anonymous@anonymous.invalid>;tag=1928301774

Please state that the tag value may be changed, but that the rest of this header form is recommended as shown.