[MMUSIC] SDP Directorate review of draft-ietf-xrblock-rtcp-xr-discard

[Jonathan Lennox <[e-mail]>]

I have been asked to perform the SDP Directorate review for draft-ietf-xrblock-rtcp-xr-discard. I reviewed the -10 version of the document.

Syntactically, the SDP usage in this document seems fine.  It is a simple and correct usage of an extension point defined in RFC 3711.

However, the statement in Section 4 that "XR blocks MAY be used without explicit signaling" is confusing, as it implies that the entire SDP section is entirely optional.  This document should at least reference Section 5 of RFC 3711, which gives guidance as to when SDP signaling of the use of XR blocks is recommended.

In the IANA considerations section, I echo Adam Roach's comments on the burst-gap-lost draft: the full and proper names of the IANA registries should be spelled out.  These are the "RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry" in Section 5.1, and the "RTP Control Protocol Extended Reports (RTCP XR) Session Description Protocol (SDP) Parameters Registry" in Section 5.2.

Additionally, the last sentence of section 4.2 is not correct English.  The sentence

   For detailed usage in Offer/Answer for unilateral parameter, refer to section 5.2 of [RFC3611].

should be

   For detailed usage of Offer/Answer for unilateral parameters, refer to section 5.2 of [RFC3611].

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Jonathan Lennox
[e-mail]