Telechat Review of draft-ietf-sfc-oam-framework-13
review-ietf-sfc-oam-framework-13-intdir-telechat-bernardos-2020-05-04-00

Thanks a lot for this document. I liked reading it.

I have a first generic comment, minor but that I still wanted to make. Section
2 is about SFC Layering Model, which to me seems like an introduction, but not
really specifically related to the core topic of the draft. Do we need that
section in this draft? Maybe it can be condensed and included as a first part
of section 3.

The document has a big component of requirements and gap analysis, which brings
one question: should the document use normative RFC 2199 language when
expressing the requirements? In Section 3.2.1 t is used, for example, but not
in other parts. I think some work is needed to make this consistent.

I think that the following sentence needs to be reworded: "In order to apply
such OAM functions at the service layer, they need to be enhanced to operate a
single SF/SFF to multiple SFs/SFFs in an SFC and also in multiple SFCs."

I think the behaviour of SFC-aware nodes that do not support a given OAM
operation should be better explained. For example, the sentence "When an SF
supports OAM functionality, it is desirable to process the packet and provide
an appropriate response to allow end-to-end verification." might be to vague.

Table 4 has a small formatting issue in the Classifier row.

I think some in-band vs out-band OAM discussion would be interesting to add to
the document.