Session Date/Time: 28 Jul 2022 20:00

rift

Summary

The RIFT working group session at IETF 114 covered updates on the RIFT base specification, Auto Flood Reflection (Auto FR), and Auto EVPN drafts, as well as the Key-Value (KV) registry structure. A significant portion of the meeting focused on addressing diagram inconsistencies in the base spec for accessibility and clarity. Discussions also highlighted the integration of RIFT's distributed state capabilities for bootstrapping Auto FR and Auto EVPN topologies. The session concluded with a proposal to recharter the working group to explicitly include adopted work (Segment Routing) and ongoing or planned work (KV registry, Auto FR, Auto EVPN, and multicast).

Key Discussion Points

Logistics and Working Group Status:
- Welcome and reminders about IETF policies, mask-wearing, and using the on-site tool for attendance/blue sheet.
- Updates on working group documents: Applicability statement is pending review, YANG models submitted to ISG, KV registry reached consensus with IANA and needs Shepherd write-up, and RIFT Segment Routing has been adopted as a working group document.
Base Specification Updates (Presented by Jordan Head):
- Diagram Inconsistencies: Major feedback from Alvaro highlighted that ASCII diagrams were not parallel with their SVG counterparts, impacting accessibility. While SVGs are preferred, ASCII versions need to reflect similar content.
- Textual References: Clarifying changes to textual references and diagrams were made.
- Accessibility Note: Discussion on the inability to reference specific document formats (e.g., PDF for SVG benefits) in the text due to IETF accessibility guidelines.
- Other Issues:
  - Early allocation for multicast addresses and UDP ports will be requested upon pushing version 16 of the base spec.
  - Various editorial changes, readability improvements, and reference fixes.
  - Alvaro added as a co-author, requiring a minor Shepherd update.
  - Minor fixes to the Thrift schema for alignment with the KV draft.
  - SVG fixes for sizing, scaling, and XML optimization due to a 3MB draft upload limit.
Auto Flood Reflection (Auto FR) Update (Presented by Jordan Head):
- Concept: Auto FR (an experimental draft from LSR) is well-suited for CLOS topologies. RIFT handles the underlay, and Auto FR extensions use RIFT's CTP and LIE exchanges to build a flood reflection topology on top.
- Integration with RIFT: Auto FR derives loopback addresses, System IDs (NET), and cluster IDs using the distributed state maintained by RIFT.
- Draft Work:
  - Clarified ISO address derivation in the text, previously only evident in the Thrift model.
  - Sections refactored to consolidate extensions related to Auto FR (FSM, no-tie advertisements, schema updates) for better readability.
  - A flood reflector preference value was added, requiring updates to election procedures.
  - Key-value ties were updated with editorial and normative language, aligning request criteria.
  - Reflector election procedures updated to factor in the highest preference value, in addition to existing high/low SID logic.
  - Normative language added for key-value ties, suggesting that all components should be carried for better interoperability.
- Working Group Adoption: Requested working group adoption; plans to add multi-plane considerations.
Auto EVPN Update (Presented by Jordan Head):
- Concept: Similar to Auto FR, building EVPN topologies on top of RIFT.
- Draft Work:
  - Similar structural changes to Auto FR for clarity and readability, making extensions and behavior more contained.
  - Key-value ties updated with normative language and IANA-related tightening.
  - Model changes, including the requirement for the version fabric ID and Auto EVPN model to be advertised in a no-tie at least once in each direction for interoperability.
  - Complementary schema updates.
- Key-Value Ties: Telemetry model changes in common Thrift, aligning with IANA requests for well-known OUI and experimental key types.
- Next Steps: Continued work on data center interconnect (DCI) aspects with a different Auto EVPN model, multi-plane considerations, and operational deployment considerations.
Key-Value Structure Update (Presented by Jordan Head):
- Restructuring: The KV registry structure was refactored to align with IANA expert review requirements, guidance, and registry structure.
- IANA Registry Discussion: An IANA early review had questioned requesting a registry (top-level RIFT category) that didn't yet exist. It was clarified that the base spec requests this top-level registry, and the KV draft will be published after the base spec, ensuring the registry exists by then. The request will remain in the main base spec.
- Open Source Implementation: Tony P. reported that Jordan is pushing the newest draft versions, and Tony is updating Bruno's open-source RIFT implementation to the latest spec, expected to be complete and tested within 1-2 weeks.
Working Group Rechartering Discussion:
- Need for Update: The current charter covers the base spec, applicability statement, and YANG model, all progressing well. However, recent work (KV registry, Auto EVPN, Auto FR, Segment Routing) is not explicitly covered.
- Proposed Inclusions: The proposal is to update the charter to explicitly include:
  - All work related to the Key-Value registry.
  - Work where RIFT is used for bootstrapping, such as Auto EVPN and Auto FR.
  - RIFT Segment Routing (already adopted but not explicitly in the charter).
  - Multicast work, which has been stalled but is planned to restart after the next IETF, to avoid off-charter work.
- Multicast Potential (Tony P): Tony P. noted that RIFT's capabilities in distributed stable election (via Auto EVPN/FR) could potentially resolve the long-standing multicast dilemma of merging trees at the top, offering a unique opportunity for protocol design.
- Consensus: The chairs will send proposals for the updated charter to the mailing list for discussion.

Decisions and Action Items

Decision: The request for the top-level RIFT IANA registry will remain in the base specification draft, as the KV registry draft will be published after the base spec, by which time the top-level registry is expected to exist. (00:21:30)
Action Item: Jordan Head will email the chairs to request early allocation for multicast addresses and UDP ports when pushing Base Spec version 16. (00:08:00)
Action Item: The working group chairs will send proposals for charter updates to the mailing list to initiate discussion. (00:27:00)
Action Item: Tony P. will complete the update of Bruno's open-source RIFT implementation to the newest specification within the next 1-2 weeks, including testing against the Juniper implementation. (00:23:00)

Next Steps

Continue refining the RIFT base specification, addressing remaining editorial and diagrammatic feedback.
Complete the Shepherd write-up for the KV registry.
Further develop Auto Flood Reflection and Auto EVPN drafts, targeting working group adoption, which will require the proposed charter update.
Engage in mailing list discussions regarding the proposed working group rechartering.
Plan to restart work on RIFT multicast after the next IETF, leveraging the protocol's unique capabilities.