Files
fips/docs/design
Johnathan Corgan 5d7af5b478 Implement FilterAnnounce send/receive, remove TTL/K-hop scoping
Add bloom filter reachability announcement protocol:
- FilterAnnounce encode/decode (wire format 0x20, 1035 bytes)
- node/bloom.rs: send/receive with debounce, split-horizon loop prevention
- Handler wiring: dispatch, tick, peer promotion/removal, cross-connection
- Five integration tests: 10-node, star, chain, ring, 100-node convergence

Remove TTL/K-hop mechanism from code and design docs after discovering
that per-entry TTL scoping is fundamentally incompatible with flat bloom
filter merge + regeneration architecture. Each node re-originates filters
with fresh TTL, making propagation unbounded regardless of TTL value.
Split-horizon remains the primary loop prevention mechanism.

Document spanning tree known limitations (v1) in spanning-tree-dynamics.md.

316 tests pass, clean build, zero warnings.
2026-02-11 03:16:25 +00:00
..

FIPS Design Documents

Protocol design specifications and analysis for the Federated Interoperable Peering System.

Suggested Reading Order

Start with the high-level architecture, then work through session flow, routing concepts, and finally the wire-level protocol details.

1. Introduction and Overview

Document Description
fips-intro.md Protocol introduction: goals, concepts, architecture

2. Protocol Flow (How Traffic Works)

Document Description
fips-session-protocol.md End-to-end session flow, Noise IK encryption, terminology

3. Routing (How Packets Find Their Way)

Document Description
fips-routing.md Routing concepts: bloom filters, discovery, greedy routing
spanning-tree-dynamics.md Tree protocol behavior: convergence, partitions, recovery
fips-gossip-protocol.md Wire formats: TreeAnnounce, FilterAnnounce, Lookup messages
Document Description
fips-wire-protocol.md Transport layer: Noise IK, session indices, roaming, security
fips-transports.md Transport-specific: UDP, Ethernet, Tor, radio characteristics

Implementation

Document Description
fips-architecture.md Software architecture: entities, state machines, configuration
fips-tun-driver.md TUN interface driver: reader/writer threads, ICMPv6, packet flow
fips-state-machines.md Phase-based state machine pattern: peer lifecycle, transitions

Document Cross-References

                      fips-intro.md
                           │
              ┌────────────┴────────────┐
              ▼                         ▼
    fips-session-protocol.md    fips-architecture.md
              │                         │
    ┌─────────┴─────────┐               ▼
    ▼                   ▼         fips-transports.md
fips-routing.md   fips-wire-protocol.md
    │       │
    ▼       ▼
spanning-tree-dynamics.md ←→ fips-gossip-protocol.md