Markdown Version | Session Recording

Session Date/Time: 21 Jul 2025 10:00

# mpls

## Summary

The MPLS working group meeting covered several topics, including updates on the MNA header, MLDP Yang model, MPLS support for deterministic latency, signaling M&A capabilities using IGP, an MPLS network action for stack management, stateless MNA-based egress protection, metadata in SR service programming, and using MNA to collect information about explicit congestion notification (ECN). Discussions focused on the readiness of drafts, potential issues with hardware implementations, encoding methods, and the applicability of MNA to various networking challenges.

## Key Discussion Points

*   **MNA Header:** An updated version was posted and is considered ready for the next step.
*   **MLDP Yang:** Working group last call requested after addressing final routing director review comments. Affiliation and IDNITS issues to be addressed in the next revision. Concern raised about whether potentially controversial comments from reviewer warranting broader WG input.
*   **MPLS for Deterministic Latency:** Updates shared, following progress of DetNet WG.
*   **Signaling M&A Capabilities via IGP:** Discussion about signaling the maximum size of NAS per scope and available opcodes. Concerns raised about the suitability of IGP for non-dynamic information and the need for an interdomain solution.
*   **MPLS Network Action for Stack Management:** Presentation of a new network action for stack management with move-end and pop-end operations.  A proof-of-concept implementation at 400Gbps was demonstrated.
*   **Stateless MNA-based Egress Protection (SMAP):** Presentation of SMAP, which uses a pop-n label operation.
*   **Metadata in SR Service Programming:** Discussion about metadata encoding for SR service programming.
*   **MNA for ECN:** Proposal to use MNA for collecting information about ECN, either as Instac data or Post-stack data.

## Decisions and Action Items

*   **MNA Header:** Tarak (Shepherd) to look at the next step to progress the document.
*   **MLDP Yang:**
    *   Kamran to address affiliation and IDNITS issues.
    *   Kamran to involve the working group if recursive fact/opaque data comments remain controversial.
    *   Tarak to follow progress as the document shepherd
*   **Signaling M&A Capabilities via IGP:** Liaise with LSR working group. Explore Yang as an alternative signaling mechanism.
*   **Stateless MNA-based Egress Protection (SMAP):** Consider generalizing protection mechanism to transit nodes in addition to egress nodes. Evaluate conditional pop-n action through reserved bits.
*   **MNA for ECN:**  Authors to align document with RFC 6040.

## Next Steps

*   Continue discussions on the mailing list for all drafts.
*   Address feedback and comments received during the meeting in updated drafts.
*   Advance the MNA Header draft towards publication.
*   Initiate Working Group Last Call for MLDP Yang after resolving remaining review comments and other issues.