Hi,

I have reviewed this document as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG.  These comments were written with the intent of improving the operational aspects of the IETF drafts. Comments that are not addressed in last call may be included in AD reviews during the IESG review.  Document editors and WG chairs should treat these comments just like any other last call comments. 

I would summarise this document as being Not Ready.

My concern with the draft lies with privacy aspects. While the area is not one that I am particularly familiar with, but there would seem to be additional potential exposure through this method, and the language of the draft seems at odds with the language in RFC6454 (Section 7.3). I would therefore urge the AD to review this aspect, and to determine whether the utility of the draft outweighs the privacy concerns, and if it does, that appropriate privacy ‘knobs’ are included for those who are ‘privacy-sensitive’ (in the language of RFC6454).

I think the rationale and tradeoffs could be more clearly stated in the document. With recent passive pervasive monitoring threats, the IETF is now supposed to be considering whether  given information *needs* to be transmitted in any given protocol.

Would I as a user, for example, be able to toggle a setting that would mean my ORIGIN would always be “null”, as per RFC6454 section 7.3? Is the use of ORIGIN *required*, or is it just ‘desirable’? Would my application fail, or not? It appears from Section 1 that its inclusion is ‘useful’, but not required.

Section 4 talks of TLS for avoiding eavesdropping of ORIGIN in STUN messages, but the privacy concern is not necessarily only with transmission of the information. I think here paragraph 3 of Section 4 is at odds with RFC6454 Section 7.3 - with this draft saying MAY wrt use of a “null” Origin, and RFC6454 saying MUST for use of “null”. The same applies to the end of the last paragraph in Section 4 as well.

The draft should probably use the ‘privacy-senstive’ context terminology of RFC6454, as per Section 7.3, and describe how the user can influence the privacy settings where they which to maximise their privacy.

Tim