With PTP 1588, AES67, and SMPTE 2110, we can transmit synchronous audio and video with sub-millisecond latency over the asynchronous medium Ethernet. But how do you make hundreds of devices agree on the exact same nanosecond on a medium that was never meant to care about time? Precision Time Protocol (IEEE 1588) tries to do just that. It's the invisible backbone of realtime media standards like AES67 and SMPTE 2110, proprietary technologies such as Dante, and even critical systems powering high-frequency trading, cellular networks, and electric grids.