FIG. 1 depicts an example system that includes a network interface and time-synchronization circuitry. An example system can include a circuit board with Ethernet compatible signal generation and processing circuits and time-synchronization circuitry. Small form-factor pluggable (SFP) compatible port support synchronous optical networking (SONET), Gigabit Ethernet, Fibre Channel, Passive Optical Network (PON), and other communications standards. In this example, two SFP28 compatible ports 102-0 and 102-1 are used but any number or types of ports can be used. Physical layer interfaces (PHY) 104-0 and 104-1 can format or reconstruct signals according to applicable physical layer specifications or standards. In this example, an Ethernet media access controller (MAC) 108 can be used to perform media access control encoding or decoding in accordance with applicable standards. Not shown are other layers of packet processing of received or transmittable packets using a network interface or host device.
