**Session Date/Time:** 26 May 2026 14:00

# [SCHC](../wg/schc.html)

## Summary
The SCHC Working Group held an interim meeting to review document status, receive a technical presentation on ARC FEC (Forward Error Correction) mode using XOR streaming, announce leadership changes, and discuss the progress of the SCHC Architecture Design Team. 

A significant leadership transition was announced by Area Director Éric Vyncke: Marion Dumay is appointed as the new WG Co-Chair, and Quentin Lampin is appointed as a Technical Advisor. Pascal Thubert will step down around IETF 126 in Vienna.

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## Key Discussion Points

### 1. Administration and Document Status
Alexander Pelov presented the [Chair Slides](https://datatracker.ietf.org/meeting/interim-2026-schc-08/materials/slides-interim-2026-schc-08-sessa-chair-slides-00) and gave a status update on active WG documents:
* **[draft-ietf-schc-over-networks-prone-to-disruptions](https://datatracker.ietf.org/authors/draft-ietf-schc-over-networks-prone-to-disruptions/)**: The WG is waiting for an updated version of the draft before initiating a Working Group Adoption Call.
* **[draft-ietf-schc-protocol-numbers](https://datatracker.ietf.org/authors/draft-ietf-schc-protocol-numbers/)**: A shepherd has been assigned.
* **[draft-ietf-schc-8824-update](https://datatracker.ietf.org/authors/draft-ietf-schc-8824-update/)**: Alexander Pelov is shepherding this document. The review has begun, and feedback will be provided in June, ahead of IETF 126. Marco Tiloca was asked to upload a new version to keep the draft active.
* **Expired Documents**: The chairs will reach out to the authors of expired WG documents to clarify their intentions (e.g., preparing for WG Last Call).

### 2. ARC FEC Mode and XOR Streaming Performance
Javier FERNANDEZ presented a proof-of-concept (PoC) implementation and performance analysis for ARC FEC Mode (an individual draft proposing a new FEC-based fragmentation mode).
* **Technical Details**:
  * The mechanism uses two different encoding geometries (matrix or buffer). The buffer geometry enables simpler algorithms like XOR.
  * The PoC features a highly memory-efficient implementation of the stream encoder, fragmenter, decoder, and reassembler without duplicate buffers.
  * Uses a 2-out-of-3 XOR parity scheme combined with a simple interleaving pattern to provide robustness against burst errors.
* **Simulation Results**:
  * Tested across link loss probabilities ranging from 10% to 50%.
  * Even under high loss scenarios (e.g., 50% link loss), the combined FEC and ARQ mechanism achieved an approximate 80% success rate.
  * Alexander Pelov noted that the simulation metrics clearly demonstrated FEC successfully recovering the majority of packages without needing ARQ retransmissions. 
  * Javier FERNANDEZ will share the repository link with the group and provide more detailed slides at the next meeting.

### 3. WG Leadership Updates
Area Director Éric Vyncke joined the session to announce changes in the SCHC Working Group leadership:
* **Marion Dumay** has been selected as the third WG Co-Chair.
* **Quentin Lampin** has been appointed as a WG Technical Advisor to provide technical guidance without formal chair duties.
* **Pascal Thubert** will step down from the Co-Chair role around IETF 126 in Vienna as he transitions into retirement.

### 4. SCHC Architecture Advancement
The group reviewed the status of the SCHC Architecture Work, referring to the [SCHC Architecture Advancement (reminder)](https://datatracker.ietf.org/meeting/interim-2026-schc-08/materials/slides-interim-2026-schc-08-sessa-schc-architecture-advancement-reminder-00) slides.
* Quentin Lampin summarized the core architectural definitions (endpoints, instances, contexts, domains, sessions) established by the Design Team.
* **Open Issue**: Multiplexing multiple sessions over the same link (the encapsulation/multiplexing/transport placeholder). The Design Team is currently cataloging existing IETF protocols that could address this.
* Alexander Pelov and Quentin Lampin invited interested participants to join the open Design Team.

### 5. IETF 126 Planning
* A 1.5-hour slot has been requested for IETF 126.
* Efforts will be made to avoid scheduling conflicts for key contributors, specifically Carsten Bormann and Marco Tiloca.

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## Decisions and Action Items

* **Leadership Appointment**: Marion Dumay officially joins as WG Co-Chair; Quentin Lampin joins as Technical Advisor.
* **Action Item (Chairs)**: Contact authors of expired working group drafts to determine next steps.
* **Action Item (Design Team)**: Publish an updated version of the SCHC Architecture draft within the next two weeks.
* **Action Item (Marco Tiloca)**: Submit an updated version of `draft-ietf-schc-8824-update` to keep the document alive.

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## Next Steps
* The next interim meeting will be scheduled in two weeks.
* Javier FERNANDEZ will present detailed performance slides on the ARC FEC PoC.