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Liaison statement
LS on O-RAN – IETF YANG Module Versioning

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State Posted
Submitted Date 2022-07-20
From Group O-RAN-WG10
From Contact Jiajin Gao
To Group netmod
To Contacts Jürgen Schönwälder <>
Thomas Nadeau <>
Cc Robert Wilton <>
Lou Berger <>
Joel Jaeggli <>
Kent Watsen <>
Warren Kumari <>
Network Modeling Discussion List <>
Response Contact
Purpose For action
Deadline 2022-09-30 Action Needed
Attachments S2022004 - LS on O-RAN - IETF YANG Module Versioning.docx
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

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-versioningdraft-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
O-RAN Alliance Face-to-Face Meeting     October 17-21, 2022     Madrid, Spain