TIPTOP

IETF 125 - Shenzhen, China

Summary

The TIPTOP (Targeted IP Transport Optimizations for Space) working group met to discuss the progress of its use case and architecture documents, and to review proposals for QUIC optimization in deep space. Key highlights included the update of the use case draft with new requirements for location and energy, a detailed response to adoption call comments for the architecture draft leading to a consensus for adoption, and an extensive discussion on the administrative and technical challenges of IP addressing for celestial bodies.

Key Discussion Points

1. Working Group Status and Administration

Chairs: Zahed Uz Zaman, Padma Pillay-Esnault Note Takers: Marc Blanchet, Adam

The TIPTOP WG Chairs Slides were presented, covering the Note Well and current document status.
The chairs noted that draft-many-tiptop-ip-architecture recently completed an adoption call with significant feedback.

2. Use Case Document Update

Presenter: Wesley Eddy Draft: draft-ietf-tiptop-usecase Slides: Use Case Document

Updates: Added definitions for Lagrange points and the Lunar Gateway. Introduced two new requirements:
1. Location: Protocols must support coordinate systems beyond terrestrial latitude/longitude to account for other planetary bodies.
2. Energy: Consideration for low-power modes and energy conservation in deep space environments.
Security: Discussion regarding Post-Quantum Cryptography (PQC). Zahed Uz Zaman noted that while PQC is critical for long-lived space assets, the IETF does not yet have a single PQC standard. Sean Turner and Wesley Eddy discussed the merits of hybrid key establishment.
Group Rekeying: The group debated whether group key agreement (e.g., multicast security) should be a requirement. Zahed Uz Zaman cautioned that transport protocols like QUIC are currently point-to-point, and security requirements should follow transport architecture rather than lead it. Padma Pillay-Esnault suggested a "crawl, walk, run" approach, focusing on point-to-point first.
Connectivity: New text will be added regarding the impact of solar conjunctions, which can cause multi-day outages.

3. TIPTOP IP Architecture Update

Presenter: Marc Blanchet Draft: draft-many-tiptop-ip-architecture Slides: Draft-many-tiptop-ip-architecture Update

Adoption Feedback: Marc Blanchet detailed revisions made to address concerns from the adoption call (comments from Brita Hale, Sean Turner, Eric Vyncke, and others).
Protocol Neutrality: The draft was updated to remove QUIC as an "implicit default" transport, treating it instead as one example among others to ensure the architecture remains general.
Architecture Overview: A new Section 2 was added to define node types and end-to-end architectural views.
Security: The security section was rewritten to address 0-RTT replay attacks and key establishment at launch. Zahed Uz Zaman suggested that the document should avoid prescriptive statements like "0-RTT isn't recommended" and instead focus on the technical trade-offs.
Adoption Poll: A show of hands was taken.
- Yes: 14
- No: 2
- No Opinion: 7
The chairs determined there was rough consensus to adopt the document, pending mailing list reconfirmation.

4. Optimization of QUIC for Deep Space Transmission

Presenter: Yu Jianhao Slides: Optimization of QUIC for Deep Space Transmission: An Architecture of Performance Enhancement and Security Extension

Technical Proposal: Introduced "QuickSpace," which replaces network probing with prior knowledge (fixed windows) and uses Streaming Codes (SC) for proactive FEC to decouple loss recovery from RTT.
Proxy Architecture: Proposed a Non-Transparent Secure Proxy (NTSP) using Application Layer Data Encryption (ALDE) to allow segment optimization without compromising end-to-end payload security.
Scope Note: Eric Vyncke (Responsible AD) clarified that TIPTOP's charter does not allow for the modification of transport protocols. Jörg Ott invited the presenter to bring the research aspects to the Space Research Group (SPACERG).

5. IP Addressing for Space

Discussion Lead: Tony Li, Warren Kumari

RIR Coordination: Tony Li reported on discussions with ARIN and RIPE regarding dedicated address space for celestial bodies. He noted significant policy hurdles.
IANA Allocation: Warren Kumari suggested that the IETF should request IANA to set aside a large IPv6 block for "Space," which could then be sub-allocated to RIRs to ensure global aggregation and visibility of space-destined traffic.
Concerns: Eric Kline expressed concern that special-casing address blocks might lead to brittle code ("if prefix == space, do X"). Tony Li clarified the goal is allocation ease and aggregation per celestial body, not special protocol handling.

Decisions and Action Items

Decision: Rough consensus reached to adopt draft-many-tiptop-ip-architecture as a working group document.
Action Item: Chairs to initiate a formal adoption reconfirmation on the mailing list for draft-many-tiptop-ip-architecture.
Action Item: Tony Li to continue developing a separate draft focused on IP addressing requirements for space to avoid delaying the main architecture document.
Action Item: Wesley Eddy to bring unresolved GitHub issues (Group Key support, Forward Secrecy, Asynchronous rekeying) for draft-ietf-tiptop-usecase to the mailing list for wider consensus.

Next Steps

Reconfirm adoption of the architecture draft on the mailing list.
Refine the security and PQC requirements in draft-ietf-tiptop-usecase.
Continue coordination with RIRs/IANA regarding the proposed space-specific IPv6 allocation.
The WG intends to meet again at IETF 126.

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