I reviewed the document "YANG Data Models for the IP Flow Information Export (IPFIX) Protocol, Packet Sampling (PSAMP) Protocol, and Bulk Data Export (draft-boydseda-ipfix-psamp-bulk-data-yang-model-02) as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the operational area directors.  Document editors and WG chairs should treat these comments just like any other last call comments.

Obsoletes: 6728 (if approved) 
Intended status: Standards Track
Current IESG state: I-D Exists

Summary: 
The document aims to replace the YANG model for packet sampling (PSAMP) and bulk data collection and export via the IPFIX protocol originally defined in standard track RFC 6728 (Configuration Data Model for the IP Flow Information Export (IPFIX) and Packet Sampling (PSAMP) Protocols). The YANG data model in the document also aims to be conform with the Network Management Datastore Architecture (NMDA) defined in RFC 8342.
FYI: The YANG model is currently in review by Martin Bjorklund from YANG modeling perspective.

The document further aims to decouple the PSAMP collecting process and the IPFIX exporting process as well as defining an exporting process which does not require SCTP support. The document tries to enable the export frequency to be controlled by the exporting process, support of large IPFIX mediation functions, and flexible referencing of interfaces. The new functionality described above and the necessary restructuring of the model in RFC 6728 might become useful if done properly as an extension to RFC 6728.

However based on missing IPFIX and PSAMP expertise, unfortunately I'm not able to give a solid statement on to whether the document is capable to replace the standard track RFC 6728. Moreover the new functionality and changes to the original model require thorough and in-depth review by IPFIX and PSAMP experts.

Also as the document is largely based on RFC 6728, introducing the authors of RFC 6728 as co-authors and involving them for review would very useful. As a minimum they need to be involved as reviewers and mentioned in the Acknowledgments section.

The document is proposed to publish as an AD sponsored draft, which is not an issue per se.
It is also not forbidden but very unusual that an AD sponsored draft is proposed to replace a standard track RFC. I would be highly interested to know why this path has been chosen.

However I believe it is a substantial issue that this draft has not been discussed and supported in any IETF maillist until today. There was only a short presentation in OPSAWG WG session one year ago without any record of support. The authors are not known at IETF and have not written any other than the current draft. The authors have most likely BBF background.

As IPFIX and PSAMP WGs have already concluded, I would like to recommend _urgently_ to introduce the draft to OPSAWG maillist and ask for support. It is IMO essentially important that the document gets discussed and reviewed by IPFIX and PSAMP people available in OPSAWG and by the authors of RFC 6728 before publication. It also needs to be clarified whether the draft has been already or is going to be implemented.

In case there is no support in OPSAWG WG for this draft to replace the standard track RFC 6728 I believe it would be appropriate to publish it as an "AD sponsored Experimental RFC". It can still become a standard track RFC after getting implementation reports and appropriate community feedback on its usage.

Sorry for not being the right expert reviewer for the draft content. Therefore I've set the review result to "Partially Completed - extra reviewer is to be assigned" and hope the draft gets a proper review in OPSAWG WG and by the authors of RFC 6728.

Mehmet