**Session Date/Time:** 22 Jul 2024 20:00

# rtgwg Meeting Minutes - IETF 120 Vancouver

## Summary

The RTGWG meeting at IETF 120 in Vancouver covered a wide range of topics including multi-segment SD-WAN, revisions to the VRRP YANG model, YANG data models for ARP and IPv6 address resolution, application-aware networking, adaptive routing notification, router info advertisements, adaptive routing framework, a framework for lossless techniques in WANs, and use cases for high-performance wide-area networks.  The meeting highlighted ongoing efforts to improve network performance, resource allocation, and congestion management. Several presentations sparked discussions on the need for consolidation of different approaches and the importance of considering end-to-end network behavior.

## Key Discussion Points

*   **Multi-segment SD-WAN:** Updates on the draft, including IANA assigned option class and sub-TOVs for Geneva encapsulation. The discussion focused on the need for more reviews from Geneva experts.
*   **VRRP YANG Model Revision:**  Options for revising the VRRP MIB YANG model to address inclusive language and technical improvements were presented.  The favored approach is to define a new YANG model (ietf-vrrp-2).
*   **YANG Data Models for ARP and IPv6 Address Resolution:**  Updates on the ARP YANG model and a new draft for IPv6 address resolution YANG model (covering NDP functionalities).  A working group adoption call will be initiated for the IPv6 draft.
*   **Application Responsible Network (ARN):**  A proposal for an intermediate layer between applications and networks to enable SRv6-based network services. This sparked discussion on trustworthiness, scalability and advantages over existing mechanisms like DSCP and SRv6 SIDs.
*   **Adaptive Routing Notification (ARN) for Load Balancing:** A presentation on different mechanisms to include information for traffic path changes when local congestion occurs. Discussion focused on the potential for loops and the need for loop avoidance mechanisms.
*   **Router Info Advertisements:**  A draft proposing a generic way of flooding routing information outside of routing protocols, for example, for fast reroute purposes. The discussion covered security considerations, loop avoidance, and its relationship to existing protocols like BFD and IS-IS.
*   **Adaptive Routing Framework:**  A framework consisting of routing plan, forwarding plan, adaptive routing policy, and remote congestion detection. Different adjustment modes (weight-based, flow redirection-based, and packet-based) were discussed.
*   **Framework for Lossless Techniques in WANs:** Discussed techniques to improve high-volume data transmission over WANs by addressing challenges such as limited network capacity, congestion hotspots, and inefficient buffer utilization.
*   **High-Performance Wide-Area Network Use Cases:**  A discussion of use cases requiring higher performance than current wide-area network technologies can provide. Discussions also highlighted determinative networks and different categories of packet data and how that affects data delivery requirements.

## Decisions and Action Items

*   **VRRP YANG Model:** The working group chair will send a proposal to the working group mailing list to support the preferred approach of creating a new YANG model (ietf-vrrp-2) and gather support and objections.
*   **IPv6 Address Resolution YANG Model:** A working group adoption call will be initiated for the new IPv6 address resolution YANG model draft.
*   **Application Responsible Network (ARN):** Move discussion to the mailing list to address questions about trustworthiness, scalability, advantages, etc.
*   **Adaptive Routing Notification (ARN) for Load Balancing:** Discuss loop avoidance and potential for oscillation creating congestion, and appropriate mechanisms for that avoidance.
*   **Adaptive Routing and Congestion Notification Frameworks:** The group will perform an interim review of the solutions and approaches for congestion notification.

## Next Steps

*   Authors of several drafts were encouraged to consider DetNet and other related standards when developing their solutions.
*   Discussions on ARN, adaptive routing, router info advertisements, and related topics will continue on the RTGWG mailing list.
*   An interim meeting will be scheduled to review existing and proposed solutions for notifying upstream nodes about network events.