Method, System, and Computer Program Product for Producing Accurate IEEE 1588 PTP Timestamps in a System with Variable PHY Latency

A system, comprising:

• at least one Ethernet network device, comprising:
• a medium access control (MAC) block configured to communicate a data packet and a time of day (TOD) signal;
• a media independent interface (MII) configured to:
• receive, from the MAC block, the data packet and the TOD signal;
• sample the TOD signal to provide a sampled TOD;
• retrieve a previously sampled TOD estimate;
• determine an internal TOD estimate based on the sampled TOD and the previously sampled TOD estimate;
• and
• determine a timestamp based on the internal TOD estimate;
• and
• a physical layer chip (PHY) configured to transcode the timestamp into a data packet prior to transmitting the data packet via an output port.

A computer program product for calculating a timestamp associated with a data packet before transcoding of the data packet, the computer program product comprising at least one non-transitory computer-readable medium including one or more instructions that, when executed by at least one processor, cause the at least one processor to:

• sample a time of day (TOD) signal to provide a sampled TOD;
• retrieve a previously sampled TOD estimate;
• determine an internal TOD estimate based on the sampled TOD and the previously sampled TOD estimate;
• and
• determine a timestamp based on the internal TOD estimate.