Please see attached review. Brian I am the assigned Gen-ART reviewer for this draft. For background on Gen-ART, please see the FAQ at < http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>. Please resolve these comments along with any other Last Call comments you may receive. Document: draft-ietf-sipcore-proxy-feature-09.txt Reviewer: Brian Carpenter Review Date: 2012-09-07 IETF LC End Date: 2012-09-184 IESG Telechat date: Summary: Almost ready -------- Comment: -------- I have to say that this is a clear example of intentional feature creep in an already very complex protocol. I find it scary. I hope the WG has thought very carefully about the implications for successful interoperability. There's only a brief mention of this topic (Section 5.3.5). In future, I'd like to see this sort of document analysed against the RFC-to-be draft-iab-extension-recs, which is in AUTH48 right now. Major issues: ------------- None. Minor issues: ------------- > 4.2.1. General ... > NOTE: It is not possible to, as a Feature-Caps header field value, > convey the address of the SIP entity that inserted the Feature-Caps > header field. I cannot parse this sentence. Does it mean this? NOTE: A Feature-Caps header field value cannot convey the address of the SIP entity that inserted the Feature-Caps header field. Or does it mean? NOTE: A Feature-Caps header field value MUST NOT convey the address of the SIP entity that inserted the Feature-Caps header field. ... > For a given fc-value, as defined in section 5.3.1, feature capability > indicators are listed in a non-priority order, and any order of the > listed SIP feature capability indicators have the same meaning. This is very hard to understand. Does it mean this? For a given fc-value, as defined in section 5.3.1, the order in which feature capability indicators are listed has no significance. > 9. Security Considerations ... > Therefore, mechanisms for guaranteeing confidentiality and > authenticity SHOULD be provided. Is this SHOULD consistent with SIP in general? It seems to me that this is a case for "MUST be defined and SHOULD be activated." Nits: ----- I don't think that the labels "Figure 1" to "Figure 6" are useful. They are not referred to in the text, and they distract the reader.