Dear all,

I completed and submitted the review of -10. 
The -10 version addresses the issues I raised in the earlier review.

Thanks to the authors for the rapid update of their draft!

Cheers,
Alexander





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> On 17 Dec 2025, at 12:23, maqiufang (A) <[email protected]> wrote:
> 
> Hi, Joe, Alexander, all,
>  
> Thanks Joe for the reminder. Thanks Alexander for the careful review, all 
> good points. The authors have published a new version which tries to resolve 
> your comments below, we also tracked your comments as issues at 
> https://github.com/IETF-OPSAWG-WG/policy-based-network-acl/issues (see issues 
> #121~#125), and you may see the correlation with the PR changes here. Please 
> also see more reply below inline…
>  
> From: Joe Clarke (jclarke) [mailto:[email protected]]
> Sent: Wednesday, December 17, 2025 1:49 AM
> To: Alexander Pelov <[email protected] 
> <mailto:[email protected]>>; [email protected] 
> <mailto:[email protected]>
> Cc: [email protected] 
> <mailto:[email protected]>; [email protected] 
> <mailto:[email protected]>
> Subject: Re: draft-ietf-opsawg-ucl-acl-09 early Intdir review
>  
> I know you had to go through a lot of process hoops to do this review, 
> Alexander.  The chairs appreciate it!
>  
> I know it’s a bit later than the other reviews, but authors can you 
> acknowledge you’ve seen this?  Thanks.
>  
> Joe and Benoît
>  
> From: Alexander Pelov via Datatracker <[email protected] 
> <mailto:[email protected]>>
> Date: Saturday, December 13, 2025 at 04:44
> To: [email protected] <mailto:[email protected]> <[email protected] 
> <mailto:[email protected]>>
> Cc: [email protected] 
> <mailto:[email protected]> 
> <[email protected] 
> <mailto:[email protected]>>,[email protected] 
> <mailto:[email protected]> <[email protected] <mailto:[email protected]>>
> Subject: draft-ietf-opsawg-ucl-acl-09 early Intdir review
> 
> Document: draft-ietf-opsawg-ucl-acl
> Title: A YANG Data Model and RADIUS Extension for Policy-based Network Access
> Control Reviewer: Alexander Pelov Review result: On the Right Track
> 
> Review of draft-ietf-opsawg-ucl-acl-09
> 
> This review was done as an Early Review as requested from INTDIR.
> 
> The document is generally well-written with a clear problem statement and
> helpful examples. However, as a reviewer approaching this without having
> followed the full evolution of the draft, I have identified several
> inconsistencies regarding terminology, the architectural relationship between
> group types, and the practical implementation of group identifiers in the
> forwarding plane.
> 
> Overall, l think the document needs a rework, and depending on the discussion
> with the authors that could prove to be minor or major.
> 
> 1. Terminology
> 
> It is somewhat difficult to follow the different terminology throughout the
> document. The “terminology” section itself is quite limited, and there are 
> many
> similar or related notions used throughout. The core example is the use of
> “endpoint-group”, “group identity”, “user group”, “application group”, and
> “device group.”
> 
> 
> This inconsistency is particularly visible with the RADIUS Attribute defined 
> in
> the document, which is called “User-Access-Group-ID”. Reading the draft, this
> attribute appears to be the mechanism for the generic “endpoint group,” yet 
> the
> name seems to suggests its for "Users."
> 
> I think the document would gain in readability by explicitly defining:
> "endpoint group", "user group", "device group", and "application group". It is
> currently unclear what the actual relations are between these types. Sometimes
> there seems to be a clear hierarchy (e.g., a user uses a device to access an
> application), but other times, the groups appear “flat” (e.g., matching
> anything with a given source IP).
> 
> In the introduction (Page 3), the text states: “This document also defines a
> mechanism to establish a mapping between (1) the user group identifier (ID) 
> and
> (2) common IP packet header fields... to execute the policy-based access
> control.” * What about the “device group ID” and “application group ID”? * The
> example in Figure 1 is very user-oriented, but from my understanding,
> everything from Step 3 onwards could apply to *any* Endpoint-Group type (e.g.,
> Device-Group), not just Users.
> 
> Section “4.2. Endpoint Group” has three subsections, each giving a loose
> description of how the 3 types of groups operate. The relationship between
> these three notions is unclear. As written, the “User group” concept could
> effectively cover both Device and Application groups. Why distinguish between
> three types? It might be cleaner to define a single, generic “Policy Group” 
> and
> indicate that different entities can belong to it.
> 
> [Qiufang] Thanks for the valuable comments. A couple of terms have been 
> defined explicitly as suggested, we also add a section to clarify the 
> relation between different endpoint groups and why there is a need to 
> distinguish between these types.
> 
> You made a good point that some sections of the draft are quite specific to 
> user group and we also need consider device group and application group at 
> the same time. There are some clarification in the draft added that tries to 
> explain the intention. Please review the update and let us know if you have 
> further comments.
> 
> 
> 2. Precision of Language
> 
> In Section “4.2.1. User group,” the text states: “if the user group membership
> is determined solely by the source IP address, then a given user's group ID
> will change when the user moves to a new IP address...”. * it is said that 
> “The
> user group is determined by a set of predetermined policy criteria (e.g. 
> source
> IP address, geolocation data, time of day, or device certificate)”. * “if the
> user group membership is determined solely by the source IP address, then a
> given user's group ID will change when the user moves to a new IP address that
> falls outside of the range of addresses of the previous user group.”
> 
> The wording seems awkward. How does the user “move to a new IP address”?
> 
> [Qiufang] Sorry for the bad wording. Have fixed this in 
> https://github.com/IETF-OPSAWG-WG/policy-based-network-acl/pull/127/:
> 
> S/move to a new IP address/ is assigned a new IP address/
> 
> 
> 3. Scenarios
> 
> There are many scenarios and use-cases mentioned. Explicitly defining some of
> the major scenarios would be beneficial. For example: * NAS with native 
> support
> for Group-based Policies. * NAS that does not support Group-based Policies.
> 
> More specifically: Section 4.1, bullet point 4 (The Policy Enforcement Point)
> ends with “More details are provided in Section 8”. However, Section 8 is 
> quite
> generic and does not seem to provide the detailed scenarios promised in the
> overview.
> 
> [Qiufang] Fixed by removing this sentence.
> 
> 
> 4. Implementation Details and Interoperability
> 
> On Page 12 it is stated: "How the 'group-id' string is mapped to the tagging 
> or
> field in the packet header in encapsulation scenario is outside the scope of
> this document.”.
> 
> I am not sure if there was a discussion at the WG level about this. It seems 
> to
> me that leaving this entirely out of scope could lead to interoperability
> issues. String-based matching in the forwarding plane can be expensive. Adding
> a field such as `NumericGroupID` and `NumericGroupType` would not be too
> expensive implementation-wise and would significantly aid interoperability 
> with
> standard encapsulations (e.g., assigning NumericGroupID = 500, 
> NumericGroupType
> = “VXLAN/GENEVE”). This, however is for the WG to decide. I am curious if this
> was discussed and agreed upon.
> 
> [Qiufang] The authors have tracked this at 
> https://github.com/IETF-OPSAWG-WG/policy-based-network-acl/issues/124, and 
> internally think it might be hard to give a stable and unified mapping 
> mechanism here. And such a NumericGroupID definition might be 
> protocol-dependent thus we tend to leave this as augmentation for future 
> work. But it would also be good to receive more comments and feedback from 
> the WG here.
> 
> 
> 5. RADIUS Considerations
> 
> Regarding "6. User Access Control Group ID RADIUS Attribute":
> * "Access-Reject vs. Restricted Accept:" Table 4 lists the attribute quantity
> for Access-Reject as "0". However, the introduction states that authentication
> failure might result in the user being "assigned a special group with very
> limited access permissions". * Usually, an "Access-Reject" terminates the
> session (no attributes processed). If the intent is to assign a "special 
> group"
> for limited access, this would technically be a "Restricted Access-Accept". 
> The
> text should clarify if this scenario results in a Reject (with 0 attributes) 
> or
> an Accept (with the special Group ID).
> 
> [Qiufang] Maybe check 
> https://github.com/IETF-OPSAWG-WG/policy-based-network-acl/issues/125 and the 
> updates in 
> https://github.com/IETF-OPSAWG-WG/policy-based-network-acl/pull/129 to see if 
> this is good enough. Thanks a lot!
> 
> Best Regards,
> Qiufang //co-author

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