This document has been reviewed as part of the transport area review team's
ongoing effort to review key IETF documents. These comments were written
primarily for the transport area directors, but are copied to the document's
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Major issues
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None

Minor issues
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1/ Section 5:

   All RTP congestion control algorithms MUST specify how they
   respond to the loss of feedback packets.

This is a process-related requirement not relevant for interoperability of implementations. In addition, the requirement is not very specific (What would have to be specified?). I am not sure if such a requirement in capital letters is really needed here. This should be handled consistently in all IETF documents.

2/ Section 11:

The Security Considerations do not discuss off-path attacks, and it is not clear why this case is missing. Can an off-path attacker trick the sender into sending at either an excessively high or excessively low rate? 

 
Nits
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1/ Abstract:

The protocol extension enables fine-grained feedback on per-packet reception quality. The rationale is provided in Section 1 and (more comprehensively) in Section 8. Yet, I wonder if this objective could also be made a bit more explicit in the abstract, e.g., along the lines of the "fine-grained feedback" wording in the first paragraph of Section 8.


2/ Section 7:

Typo in "a=ecn-capaable-rtp:"