Hi Elwyn, Thank You for the review! Please see inline. >Summary: >Ready with nits. There are a couple of minor issues related to the procedures after inappropriate usage of the new header. > >Major issues: >None > >Minor issues: > > s3.4.1, last para: In line with the last sentence of Section 3.2, the Content-ID URL only needs to be unique within the SIP message where it occurs. > I assume it does not make sense to have a Content-ID header combined with a mutipart message-body (this isn't stated - maybe it should be); I am not aware of any current use-case, but I see no reason to forbid it. Perhaps someone will come up with a use-case in future. > I am not sufficiently knowledgeable in this area of SIP to know if there could be content-id URLs in other headers if there is a Content-ID > header in the message. Thus either the statement about global uniqueness is irrelevant (as there is only one) and can be removed or it > should be made consistent with s3.2 so that the Content URLs are unique within the message. Global uniqueness is neither possible or required. The statement about global uniqueness is a bug, and will be fixed. The value only has to be unique within the message. > s3.4.1, para 1: Following on from the previous comment: Is a UA allowed to add a Content-ID header to a message with a multipart message-body? I see no reason to forbid it. > s3.4.1: What should a UA do if it receives a message with a Content-ID header when the message is not allowed to > contain one? Is there some generic error procedure that should be referenced? Normal RFC 3261 procedures apply. I don't think we want to copy/paste the generic header processing rules, > s6.1: I started looking for specification that told me that items added to the SIP header fields registry effectively > extend the definition of the message-header production in Section 25.1of RFC 3261. Bit obvious perhaps, but it > would be nice if it had been said somewhere! Time for an Erratum perhaps? In the ABNF of RFC 3261, "message-header" contains the header fields defined in the RFC, plus "extension-header", which is used for new headers. I assume people think that is clear enough :) Having said that, what you suggest is not necessarily a bad idea, but it is outside the scope of this draft. >Nits/editorial comments: > >Abstract: I would suggest adding a sentence that clarifies what the update of RFC 5621 is modifying: > >OLD: The document also updates RFC 5621, to enable a Content-ID URL to reference a complete >message-body and metadata provided by some additional SIP header fields. > >NEW: The document also updates RFC 5621, which only allows a Content-ID URL to reference a >body-part that is part of a multipart message-body. This update enables a Content-ID URL to >reference a complete message-body and metadata provided by some additional SIP header fields. END Looks ok. I will modify as suggested. >s1.2, first bullet: s/for providing location/for providing location information/ Will be fixed as suggested. >s1.4.1: Need to expand UAC (User Agent Client) on first usage. I realized the first usage is in section 1.3, so I will expend it there. >s1.4.1, para 1: s/can be e.g. of/can be, for example, of/ Will be fixed as suggested. >s3.4.1: Need to expand UA (User Agent) on first usage (in section title). Will be fixed as suggested. >s4, NEW text: s/allow creating/allow the creation of/ Will be fixed as suggested. Regards, Christer