esaProbeHistoryMaxNegR2PJitter is an unsigned 32-bit value that reports the highest recorded negative one-way jitter (packet-to-packet delay variation), in microseconds, from the reflector back to the probe, for a completed interval that has already closed and been archived into the rolling history log. Negative (a packet arriving earlier than the one before it) jitter from the reflector back to the probe is exactly the kind of packet-to-packet delay variation that causes stutter in voice and video traffic riding over the same service. For example, scanning this worst-case negative jitter from the reflector back to the probe across a week of archived bins lets the technician find the specific hour a transient spike occurred, long after the live dashboard has moved on to newer data.