I am the assigned Gen-ART reviewer for this draft. The General Area
Review Team (Gen-ART) reviews all IETF documents being processed
by the IESG for the IETF Chair.  Please treat these comments just
like any other last call comments.

For more information, please see the FAQ at

<https://wiki.ietf.org/en/group/gen/GenArtFAQ>.

Document: draft-ietf-teas-ietf-network-slices-21
Reviewer: Reese Enghardt
Review Date: 2023-07-11
IETF LC End Date: 2023-07-11
IESG Telechat date: Not scheduled for a telechat

Summary: The document does a decent job at explaining several complex concepts. It is almost ready for publication, just a few clarifying questions and nits.

Major issues: None


Minor issues:

Section 5.2

"If the CE is operated by the IETF Network Slice Service provider, then the edge of the IETF Network Slice may be within the CE. In this case the slicing process may utilize resources from within the CE such as buffers and queues on the outgoing interfaces."

What is the slicing process - does this term refer to implementing an IETF Network Slice Service? In this case, please consider substituting the terms here.

Section 6.2

"Scalability: Customers do not need to know any information concerning network topology, capabilities, or state beyond that which is exposed via the IETF Network Slice Service Interface."

I suggest adding a phrase explaining why this improves scalability in this context.

Section 7.1

"An NRP may be chosen to support a specific connectivity construct because of its ability to support a specific set of SLOs and SLEs, or its ability to support particular connectivity types, or for any administrative or operational reason."

The term "connectivity type" does not appear to be defined and only appears once. Can this term substituted by a term that is defined in the draft?


Nits/editorial comments: 

Please consider redrawing the figures using SVG instead of ASCII. Especially Figure 4 would greatly benefit from this enhancement.

Section 1

"This document also provides a framework for discussing IETF Network Slices. The framework is intended as a structure for discussing interfaces and technologies."

I find it not entirely clear what the purpose of the framework is (I assume this refers to Section 6): "Discussing" seems fairly broad, as the entire document appears to be intended to help with discussing these concepts in an IETF context. I suggest being more specific here, e.g., how about using the same wording as in Section 2: "a framework for the provision of an IETF Network Slice Service", or similar as the Abstract: "the general framework for requesting and operating IETF Network Slices"?
In addition, I suggest adding one sentence to the start of Section 6, the "Framework" section, clarifying what the focus of this section is.

Section 6.3

"The controller provides the following functions.
[…]
Determines an abstract topology connecting the SDPs of the IETF Network Slice that meets criteria specified via the IETF Network Slice Service Interface"

I find "determine" to be an odd choice of words if this phrase is about implementing the Slice. I suggest using "identify" or a similar term.

Section 7

"Realization of IETF Network Slices is out of scope of this document. […] However, this section provides an overview of the components and processes involved in realizing an IETF Network Slice."

I find it odd to start the section with a phrase saying that the section topic is out of scope. I suggest turning it around here, starting out by saying "This section provides an overview of the components and processes […]", and then ending the paragraph by saying "The details of how to realize any particular IETF Network Slice are out of scope of this document" or something similar.