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

[Glen Zorn <[e-mail]>]

On 12/17/2012 10:49 PM, Jonathan Lennox wrote:

> 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.
 >

I'm not sure why this is confusing (aside from fact that RFC 3711 is 
itself confusing: it says "although the use of SDP signaling for XR 
blocks may be optional, if used, it MUST be used as defined here". /May/ 
be optional?  Optionality seems pretty black and white to me ;-).  That 
said, however, it does seem to be relatively clear that the usage of SDP 
/is/ optional & along with it the section on SDP in this and other 
similar drafts.  What am I missing?

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