**Session Date/Time:** 07 Nov 2023 14:30

# rift

## Summary

The meeting covered updates on the base spec and KV registry drafts, results from the hackathon, and a deep dive into rift in dragonfly topologies. The base spec is nearing ISG submission. The KV registry draft now includes key target functionality. The hackathon saw successful interoperability testing. A new approach to using rift in sparse dragonfly topologies for datacenter interconnection was presented, enabling bisectional bandwidth and resilience.

## Key Discussion Points

*   **Base Spec:** Update to version 19 included schema updates for key targets, clarifications on state transitions, and security considerations around TTL/hop limit. Routing AD review is ongoing before IETF last call.
*   **KV Registry:** Key target functionality was introduced for targeted KV tie distribution using bloom filters. This addresses flooding limitations. Purging and rollover considerations were discussed. Renaming the draft was suggested to reflect the inclusion of key target behavior.
*   **Hackathon:** Successful interoperability testing between implementations was conducted, with minor issues resolved.
*   **rift in Dragonfly Topologies:**
    *   A sparse dragonfly topology was defined as a basis for datacenter interconnection.
    *   The proposal avoids a single cloth fabric homomorphism, opting for multiple rift fabrics representing separate datacenters interconnected via a sparse dragonfly backbone.
    *   The solution differentiates between intra-fabric and inter-fabric horizons using fabric IDs in hello messages.
    *   Computation and forwarding procedures were modified to account for one-hop and two-hop inter-fabric routes.
    *   The importance of an interface-specific forwarding table, building on silicon's ability to handle VPNs, was highlighted.
    *   Simplifications related to negative disaggregation were discussed.
    *   Discussion occurred regarding load balancing and multi-path considerations for shortest path.
    *   Scalability concerns of the proposed computation were also discussed.

## Decisions and Action Items

*   **KV Registry Draft Name:** Jeffrey to consider renaming the KV registry draft to reflect the inclusion of key target behavior.
*   **Applicability Document TTL Text:** Jordan to write and propose text for the applicability document regarding TTL/hop limit considerations.

## Next Steps

*   Continue review of the base spec by routing ADs.
*   Address comments on the KV registry draft and consider renaming.
*   Further discussion and potential drafting related to rift in dragonfly topologies.
*   Further mental exercises to break or support the structure holds.