Packet Sampling (PSAMP) Protocol Specifications
RFC 5476

Review by Christian Vogt:

Draft-ietf-psamp-protocol-09 specifies how the IP Flow Information
Export (IPFIX) protocol is used to communicate packet information
between network measurement entities in a PSAMP architecture.  The
protocol was not originally designed for the PSAMP architecture.

A few editorial/structural comments on how the understandability of the
document could be improved for a non-expert reader.  None of these
comments is a technical show-stopper:


(1)  Section 3.2 in this document repeats many of the terminology
definitions from section 3.1 in draft-ietf-psamp-sample-tech-10.  This
makes terminology updates and extensions unnecessarily cumbersome.  I
suggest moving all PSAMP-related terminology into a separate document,
and citing that document where needed.


(2)  Section 3.3.1 does not compare PSAMP-related and IPFIX-related
terminology, which it is supposed to do according to the introduction of
section 3.3.  Instead, section 3.3.1 simply describes PSAMP-related
terms, and thus basically repeats parts of section 3.2.  A comparison
with the relevant IPFIX-related terminology should be added.


(3)  In section 3.3.2, the difference between a PSAMP Packet Report and
a PSAMP Packet Interpretation remains unclear as both are equated to the
same combination of IPFIX terms.

Also, the term "Packet Interpretation" in section 3.3.2 should likely be
replaced by "*Report* Interpretation" according to PSAMP terminology.


(4)  Section 4.2:  Is the underlying architectural difference between
PSAMP and IPFIX, which is relevant here, that aggregation may in IPFIX
happen before data is exported, but not in PSAMP?  If this is correct,
then stating this explicitly would increase the clarity of this section.

I found Section 5's discussion of the requirements in [PSAMP-FMWK] hard to follow.
I had to read section 4 of that document to sort out that the following paragraphs address
subsections of the "Generic Requirements for PSAMP" referred to in the opening paragraph.

The fact that the second paragraph focused on requirements that indirectly relate to the
prtotocol contributes to the confusion.  The opening paragraph of section 5 explicitly
calls out "requirements that affect directly the PSAMP export protocol."