Session Date/Time: 23 Oct 2023 15:00

IETF3GPP

Summary

This IETF3GPP coordination meeting focused on reviewing the ongoing liaison statements, IANA actions, and dependencies between IETF and 3GPP. The session was impacted by initial technical difficulties with the Meetecho platform, preventing slide sharing and chat functionality for a portion of the meeting. Despite these issues, the co-chairs presented an overview of key activities, including the status of various IETF drafts impacting 3GPP specifications, and discussed new work items in other IETF working groups relevant to 3GPP.

Key Discussion Points

Meetecho Technical Issues: The session began with significant technical difficulties, preventing co-chairs from sharing slides and participants from using the chat function. Co-chairs Peter and Charles attempted various troubleshooting steps, including re-logging in. Eventually, the ability to share slides was restored, but the chat remained non-functional. The presentation proceeded with Peter announcing slide numbers for those following along offline.
Agenda Overview:
- The primary agenda item was an update on IETF-3GPP coordination, based on slides prepared for 3GPP.
- A smaller, in-person IETF3GPP session is planned for IETF 118 in Prague on Monday during the lunch break to address more specific topics.
IETF-3GPP Coordination Update (Co-Chair Peter's Presentation):
- Ongoing Actions:
  - RFC 3113 update is still needed.
  - Updating or creating a new dependency list tool with IETF support remains an open action.
- IETF-3GPP Liaison Statements:
  - LS on SCTP (from IETF TSVWG):
    - Feedback from SA3 indicated that IETF's interpretation of security requirements is correct and generic best practice. SA3 prefers "solution 2" for its perceived lower implementation effort.
    - RAN3 expressed a strong preference against limiting the maximum message size of the application protocol, appreciating solutions without such limitations.
    - The problem is not yet solved within TSVWG, but no further liaison input is currently requested from 3GPP.
  - LS on YANG Modeling (from 3GPP to IETF NETMOD):
    - A solution to represent "is-invariant" and "system-created" properties in IETF-defined YANG statements is needed to support 3GPP SA5 YANG data models.
    - draft-ma-netmod-yang was identified as a potential solution. A poll for adoption was open until September.
    - There was some support but also concerns. This will be a topic of discussion at IETF 118 in Prague.
  - LS on Network Slicing (from IETF TEAS to 3GPP):
    - Sent in October 2023 for information, informing 3GPP WGs (SA2, SA3, SA5, RAN3) about IETF's framework for network slicing.
    - SA2, SA3, SA5 have scheduled discussion for their November meetings (after IETF 118, except SA3 which is same week).
    - RAN3 noted no interaction with its current ongoing work and only noted the LS. No specific action was requested from 3GPP.
- IANA Actions:
  - All Release 17 IANA assignment requests are closed.
  - New requests are anticipated for Release 18 specifications as they near completion. Co-chair Peter noted a need to be more proactive in triggering these requests to avoid delays seen with Release 17.
- IETF-3GPP Dependencies:
  - Published RFCs:
    - RFC 9410 is referenced in CT documentation, and the issue is considered resolved on both sides.
    - An extension of Data-Crum Transport Layer Security work in IETF is complete; 3GPP SA working groups are expected to update their TSs to reference the new RFC.
  - Drafts in RFC Editor's Queue: draft-ietf-tictoc-ptp-psf and draft-ietf-tictoc-tns-messaging are awaiting RFC publication.
  - Drafts Under IESG Review: draft-ietf-netmod-yang-versioning is still in the review process.
  - Documents Active in Working Groups:
    - draft-ietf-quic-multipath: A new reference added by SA2. IETF working group completion is awaited.
    - draft-ietf-core-oscore-network: Referenced in 3GPP TSs. Discussion occurred in the CORE WG, but no clear resolution since June. Co-chair Charles plans to follow up with the draft author and CORE chairs.
  - Individual Submissions (referenced in 3GPP TSs):
    - draft-bops-szt-attachment-circuit: Referenced in SA5 TS 28.541. The BOPS WG has had an adoption call with significant support, but consolidation with other documents is being considered. This draft was not correctly reported in the 3GPP work plan, highlighting a process improvement need.
    - draft-schwarz-media-stcp-gateways: Expired in 2016 but still referenced in 3GPP TSs. This protocol relates to H.248, and finding an expert for its completion is proving difficult.
Any Other Business / New Topics:
- IPv6 over V2X (6MAN WG): A presentation is scheduled for IETF 118 in 6MAN regarding running IPv6 over V2X. It's not yet a working group item but an informational presentation.
- SRv6 in DMM WG: Ongoing work in DMM to write informational documents on using SRv6 for 3GPP Operator functions, e.g., extensions for SRv6 mobile user plane network programming (RFC 9433 and related follow-ups).
  - 3GPP previously studied replacing GTP with SRv6 during Rel-16 (5G), but operators did not see a significant financial advantage, leading to it not being pursued within 3GPP specifications.
  - Such a discussion might be revisited for 6G (likely Release 20 or 21).
- Evolution of Mobile User Plane (DMM WG): draft-zang-dmm-mup-evolution is an individual draft proposing an architectural evolution for 3GPP at a higher level, aiming to simplify reference points between RAN and Core Network by leveraging DMM and potentially SRv6. This is not an IETF specification target but an architectural proposal for 3GPP.

Decisions and Action Items

Decisions:

The IETF3GPP coordination activities will continue to track identified liaison statements and IETF draft statuses impacting 3GPP.
Efforts will be made to proactively engage with 3GPP for Release 18 IANA assignment requests to ensure timely processing.
The status of NETMOD draft adoption (draft-ma-netmod-yang) and CORE working group resolution on draft-ietf-core-oscore-network remain open items to be addressed.

Action Items:

Charles (Co-Chair):
- Follow up with the author and CORE working group chairs regarding the status and resolution of draft-ietf-core-oscore-network.
Peter (Co-Chair):
- Improve the process for tracking IETF drafts and documents that are referenced in 3GPP Technical Specifications, especially those not correctly appearing in the 3GPP work plan.
- Proactively trigger Release 18 IANA assignment requests within 3GPP to ensure timely submission and processing.
- Continue searching for an expert to resolve the status of the expired draft-schwarz-media-stcp-gateways which is still referenced in 3GPP TSs.
Participants:
- Be aware of relevant documents in other working groups (e.g., IPv6 over V2X in 6MAN, SRv6 and MUP evolution in DMM) and inform the IETF3GPP co-chairs if they believe these require specific attention or tracking.

Next Steps

A smaller, in-person IETF3GPP session is scheduled for IETF 118 in Prague on Monday during the lunch break to delve into more specific topics identified in this meeting or by participants.
Further information regarding the agenda and logistics for the IETF 118 session will be distributed via the mailing list.
The co-chairs will continue to track the ongoing work and new dependencies discussed in this meeting.