udp_echo and tcp_echo run at the lowest rate that still proves the loss bound and keeps the RTT p99 confidence interval within tolerance, go to the maximum when the line loses packets or its RTT rises, and back off exponentially when it is unreachable. Every echo row carries a weight (the time it stands for, in grid intervals) and the analysis ops accumulate loss and RTT by it, so p50/p95/p99 and loss stay time-averaged when the rate changes. State changes are logged for audit.
Replace Probe with Agent across node runtime, Fleet contracts, backend state, API and storage. Report incoming sessions and outgoing link health through each Agent uplink, and retain directed link controls and retry.
Update protocol fixtures and end-to-end coverage for the unified model; accept requested cancellation during the Fleet timeout test cleanup.
justme