[netmod] New Liaison Statement, "LS on O-RAN – IETF YANG Module Versioning"

[Liaison Statement Management Tool <[e-mail]>]

Title: LS on O-RAN – IETF YANG Module Versioning
Submission Date: 2022-07-20
URL of the IETF Web page: https://datatracker.ietf.org/liaison/1785/
Please reply by 2022-09-30
From: Jiajin Gao <[e-mail]>
To: Jürgen Schönwälder <[e-mail]>,Thomas Nadeau <[e-mail]>
Cc: Robert Wilton <[e-mail]>,Lou Berger <[e-mail]>,Joel Jaeggli <[e-mail]>,Kent Watsen <[e-mail]>,Warren Kumari <[e-mail]>,Network Modeling Discussion List <[e-mail]>
Response Contacts: [e-mail]
Technical Contacts: 
Purpose: For action

Body: 1. Overall Description:
The O-RAN Alliance is committed to evolving radio access networks, making them more open and smarter than previous generations. The key principles of the O-RAN Alliance include: 
-	Lead the industry towards open, interoperable interfaces, RAN virtualization, AI/ML and big data enabled RAN intelligence.
-	Specify APIs and interfaces, driving standards to adopt them as appropriate, and exploring open source where appropriate.
-	Maximize the use of common-off-the-shelf hardware and merchant silicon and minimizing proprietary hardware.	

The O-RAN Alliance (O-RAN) is developing specifications and software to enable a more competitive and vibrant Radio Access Network ecosystem with faster innovation. As part of this effort, O-RAN is developing OAM interfaces that expose data models written in the YANG modelling language. O-RAN has developed YANG modules and plans to have frequent releases of these YANG modules (multiple times a year). 

O-RAN needs a robust module versioning system for YANG modules. As O-RAN modules are updated frequently and the modules are still evolving, it is foreseen that there will be several changes to the modules in the future, including non-backwards compatible changes. O-RAN is looking for a method to mark the non-backward compatible changes. 

A mechanism to allow importing YANG modules by semantic version is furthermore needed to manage dependencies between O-RAN YANG modules, as well as toward YANG modules defined by other standardization groups (for example, IETF or 3GPP).

Similar needs have already been discussed in IETF; this discussion can be found in draft-ietf-netmod-yang-versioning-reqs. 

ORAN would like to use a ratified IETF-provided solution for YANG module versioning. Using draft IETF specifications would not be possible due to possible changes that might come before the RFC is officially approved. 

For the above reasons, O-RAN WG10 would like to notify the IETF NETMOD working group that it has an urgent need for a final ratified version of the drafts:

•	draft-ietf-netmod-yang-module-versioning
•	draft-ietf-netmod-yang-semver
Note that O-RAN may be forced to produce its own solution if these two requested IETF drafts do not progress.

It is understood that the above drafts are currently discussed in IETF together with three other drafts, namely draft-ietf-netmod-yang-packages, draft-ietf-netmod-yang-ver-selection and draft-ietf-netmod-yang-schema-comparison. However, O-RAN would like to emphasize that the two documents listed above are needed urgently, independent of the latter three documents. 

2. Actions:
To: IETF NETMOD working group
ACTION: O-RAN would like to ask when the two IETF drafts draft-ietf-netmod-yang-module-versioning and draft-ietf-netmod-yang-semver will be approved, independent of the status of any other drafts, and at the same time emphasize the urgent need for this approval.

3. Date of Next O-RAN Meetings:
       O-RAN WG10 have regular weekly meetings where all contributions are considered.
O-RAN Alliance Face-to-Face Meeting	October 17-21, 2022	Madrid, Spain
Attachments:

    S2022004 - LS on O-RAN - IETF YANG Module Versioning.docx
    https://www.ietf.org/lib/dt/documents/LIAISON/liaison-2022-07-20-o-ran-wg10-netmod-ls-on-o-ran-ietf-yang-module-versioning-attachment-1.docx