I am the assigned ARTART reviewer for this draft.

Summary:

  This document is concise, clear, and generally in good shape. The overall
  approach is clear: applications using the Multicast Application Port
  are distinguished by multicast group information for ASM, or by source/group
  information for SSM, rather than by unique UDP port assignments.

  I found no major or minor issues. I found one small clarification that the
  authors may wish to consider as a nit.

Major issues:

  None.

Minor issues:

  None.

Nits:

  In Section 2, the document clearly states that applications using the
  Multicast Application Port are identified by the destination multicast
  address for ASM, or by the combination of source unicast address and
  destination multicast address for SSM.

  Given that definition, the text in Section 4 is understandable. However,
  the current sentence refers only to "the multicast address used by the
  application". For consistency with the SSM definition in Section 2, the
  authors may wish to make the SSM case explicit here as well. For example,
  the text could explicitly mention the source unicast address in the SSM case,
  consistent with the identification model introduced in Section 2.

  Similarly, Section 6 recommends that firewall rules referencing the Multicast
  Application Port SHOULD also consider the destination multicast address. For
  SSM, it may be slightly clearer to mention that the source unicast address is
  also part of the information used to identify the application, following the
  model already introduced in Section 2.

  This is not a major ambiguity, but echoing the Section 2 model in Sections 4
  and 6 would make the document more internally consistent for implementers.