draft-ietf-ippm-rfc8321bis-02

I am an assigned INT directorate reviewer for draft-ietf-ippm-rfc8321bis-02. These comments were written primarily for the benefit of the Internet Area Directors. 
Document editors and shepherd(s) should treat these comments just like they would treat comments from any other IETF contributors and resolve them along with 
any other Last Call comments that have been received. For more details on the INT Directorate, 
see https://datatracker.ietf.org/group/intdir/about/ <https://datatracker.ietf.org/group/intdir/about/>.

Based on my review, if I was on the IESG I would ballot this document as DISCUSS.

DISCUSS:
Section 3.1 
This section states two possible methods using either a fixed number of packets or fixed timer.  Only fixed
timer is defined in draft.  I would think that supporting the fixed timer method would be a MUST for implementations
of this document.

Section 3.2
Suggest a lower case must for clock network synch.    I would suggest using a capital MUST, if the clocks aren't in synch this method will
not work properly.   Additionally, I was surprised there are no suggesting on what to use to keep the clocks in synch (NTP, PTP) or precision suggested in 
time keeping mechanism.  These methods are referenced in Section 7 but I think it would make sense to give people the options in this section.

Section 7.1
While is says recommended to be a controlled domain, it should document what happens if it leaves the controlled and how to protect the borders of the domain.

NIT:
OLD:
As discussed in the previous section, a simple way to create the
   blocks is to "color" the traffic (two colors are sufficient), so that
   packets belonging to different consecutive blocks will have different
   colors."

New:
As discussed in the previous section, a simple way to create the
   blocks is to "color" the traffic (two colors are sufficient), so that
   packets belonging to alternate consecutive blocks will have different
   colors.