**Session Date/Time:** 21 Jul 2025 10:00

# panrg

## Summary

This PanRG meeting at IETF 123 featured a presentation by Tillman Zeshke on guidelines for running QUIC multipath over SCION, highlighting benefits, challenges, and security considerations.  Nicola provided a quick update on the status of the SCION core specification drafts and their progress through the IESG review process.  The meeting concluded with a brief open mic session.

## Key Discussion Points

*   **QUIC Multipath over SCION Guidelines:**
    *   Tillman Zeshke presented a draft outlining guidelines for QUIC multipath implementations over SCION.
    *   Benefits include path metadata utilization (latency, bandwidth), disjoint path selection for redundancy, and simplified congestion control.
    *   Challenges revolve around network address uniqueness (ISD-AS number, IP, port), path ID management, and path lifecycle within SCION libraries.
    *   Security considerations were discussed, particularly regarding path validation and server-side state management.
    *   The presentation prompted discussion on whether the draft should be SCION-specific or more general to address other path-aware networking technologies.

*   **QUIC and Path Awareness:**
    *   Lucas Pardue raised the point that standard QUIC (RFC 9000) already has a notion of multi-path through connection migration and wondered how much of the guidelines apply to this base functionality.
    *   The discussion considered whether the draft could address considerations for QUIC operating over different path-aware networks.
    *   It was suggested that the presenter contact the QUIC working group and the multi-path QUIC draft authors.

*   **SCION Core Specification Update:**
    *   Nicola provided an update on the SCION core specification drafts, which are currently undergoing IESG review.
    *   Recent updates include addressing feedback from a control plane review, standardizing SCION number representation, updating the SCION number registry reference, and mandating an unspecified interface ID.
    *   Ongoing work includes clarifying the use of gRPC (protocol buffer definitions) and security considerations, adding metadata extensions, and clarifying MTU handling within SCION paths.

## Decisions and Action Items

*   **Action Item:** Tillman Zeshke will contact the QUIC working group and the multi-path QUIC draft authors for feedback on the QUIC multipath over SCION guidelines draft.
*   **Decision:** The usefulness of signing SCION to improve quick multipath was noted.
*   **Action Item:** Nicola will seek further reviews on the SCION core specification drafts, particularly focusing on the ongoing work areas.

## Next Steps

*   Tillman Zeshke will revise the draft based on feedback received and further discussions with the QUIC community.
*   The SCION Association will continue working on the IESG review feedback and finalize the SCION core specification drafts.