PTP 1-step Boundary Clock (or 1-step BC) is similar to 2-step BC in function, but doesn’t send the PTP followup message. The timestamp present in the PTP followup message’s preciseOriginTimestamp field is sent in the PTP sync message’s originTimestamp field along with a non-zero correctionField.

This feature supports counting ECN marked packets (ECN Explicit Congestion Notification) on a per egress port per tx