Last Call Review of draft-ietf-xrblock-rtcp-xr-post-repair-loss-count-07
review-ietf-xrblock-rtcp-xr-post-repair-loss-count-07-secdir-lc-kelly-2015-01-02-00

I have reviewed this document as part of the security directorate's ongoing
effort to review all IETF documents being processed by the IESG.  These
comments were written primarily for the benefit of the security area directors.
 Document editors and WG chairs should treat these comments just like any other
last call comments.

Here’s the abstract:

   This document defines an RTP Control Protocol (RTCP) Extended Report
   (XR) Block that allows reporting of post-repair loss count metrics
   for a range of RTP applications.

Prior to this mechanism, RTCP Sender Reports (SR)/Receiver Reports (RR)
contain, among other things, the cumulative number of packets lost. That number
doesn’t indicate the data successfully received, because the receiver can apply
repair mechanisms to recover data. This document adds reporting for post-repair
metrics.

The security considerations seem complete, but I have one nit. Here’s the first
sentence:

   It is believed that this RTCP XR block introduces no new security
   considerations beyond those described in [RFC3611].

Who believes this? I would simply assert this (remove “It is believed that”),
and if I wasn’t comfortable with that, I’d take that as an indication that more
analysis is required.

—Scott