12 · Abrupt relay disappearance and descendant reconnection

Starting state

Active branch depends on a relay; descendants have sealed roster/keys and potentially alternative discovery neighbors.

Ordered events

1. Relay → Child

   Relay disappears without leave

2. Child → Child

   Direct liveness/root freshness expires; choose surviving component route

3. Child → Alternative

   Establish new binding/TLS/hello and transactional parent activation

4. Alternative → Descendants

   Synchronize descriptors and resume active flooding

Fields and messages

Direct liveness state, root pulse/path, desired versus active parent, new link exporter and current descriptor nextIndex.

Authorization and invariants

Known-cycle path rejection and admitted identity pinning remain mandatory under repair. Link loss cannot erase source replay protection.

Timers

Suspect/dead 3/6 s; root lease 4.5 s; discovery 6 s; setup 25 s plus scoped retries.

Resource lifetime

Membership/source keys persist; old request, hop keys and route are retired; descendants keep independent audio sessions.

What the rider sees

Members show reachability changes; local active audio may continue inside disconnected subgroup.

Failure branches

No alternate physical connectivity means a partition, not fabricated recovery. One failed relay must not reset unrelated healthy branches.

Resulting state

Only lost edges retire; descendants select a live root/parent and recover authenticated delivery where connectivity exists.

Evidence boundary

Topology partition tests, handoff disappearance tests and ten-minute wall-clock endurance. Physical mobility unqualified.