esaProbeStatsMinRoundTripDelay is an unsigned 32-bit value that reports the lowest recorded round-trip delay of the test packets, in microseconds, with the reflector's own processing time excluded, for the interval that is still being actively collected (the live bin). Round-trip delay is the core proof-of-performance number for an Etherjack SLA test because it reflects everything affecting the circuit in both directions combined, so a technician watches it to confirm the customer's contracted latency bound is being met. For example, if this minimum round-trip delay holds steady at its usual floor while spikes show up elsewhere in the same live bin, the technician watching the dashboard right now can conclude the path itself is healthy and the spikes are transient.