esaProbeHistorySumAbsP2RJitter is a 64-bit performance counter that reports the running total (sum) of the absolute-value one-way jitter (magnitude of the delay swing regardless of direction), in microseconds, from the probe to the reflector, applicable to Layer 3 ICMP-timestamp and Layer 2 Y.1731 probes, for a completed interval that has already closed and been archived into the rolling history log. Because it discards the sign of the swing, this absolute-jitter figure from the probe to the reflector gives a technician a single severity number to alarm on without watching the positive and negative jitter counters separately. For example, re-deriving the average absolute jitter from the probe to the reflector from this archived running total and the matching archived packet count lets an auditor validate the device's own math well after the fact.