Re: [xrblock] 2nd WGLC for draft-ietf-xrblock-rtcp-xr-qoe

[Colin Perkins <[e-mail]>]

On 21 Aug 2013, at 14:35, "Romascanu, Dan (Dan)" <[e-mail]> wrote:
> This is the second WGLC for the Internet-Draft 'RTP Control Protocol (RTCP) Extended Report (XR) Blocks for MoS Metric Reporting' previously known as 'RTP Control Protocol (RTCP) Extended Report (XR) Blocks for QoE Metric Reporting'. Please send your comments, questions, and concerns to the WG list before Wednesday 9/4. If you have no comments or questions and you believe that this document is ready for submission to the IESG for consideration as a Proposed Standard, please send a message stating this. 
> 
> The latest version of the document can be retrieved from http://www.ietf.org/id/draft-ietf-xrblock-rtcp-xr-qoe-10.txt.


The first paragraph of Section 3.1 talks about various flag bits in the header indicating which fields are present. However, the header doesn't appear to contain any such flags.

The header described in Section 3.2 includes an Interval Metric Flag. I understand how MOS scores can be calculated for an interval, and perhaps how they could be sampled, but not how a cumulative MOS can be measured. Should cumulative, and possibly sampled, metrics be prohibited?

Should Section 3.2.1 be titled "Single channel..." rather than "Single stream..."?

Section 3.2.1 says "For RTP sessions where multiple payload formats can be negotiated or the payload format changes during the mid-session), the value of this field will be used to indicate what payload format was in use for the reporting interval", but doesn't the payload type indicate this whether or not multiple payload formats are used in the session?

-- 
Colin Perkins
http://csperkins.org/