3 ms·
I have never seen NTP in a datacenter of reasonable size get below an error of 1e-4. PTP without custom hardware can easily get 3 orders of magnitude better.
by pclmulqdq 4y ago
I have never seen NTP in a datacenter of reasonable size get below an error of 1e-4. PTP without custom hardware can easily get 3 orders of magnitude better.
- bradknowles 4y agoPTP is harder to do within a datacenter. You either need hardware support in every switch and network interface, or you're doing software timestamping at which point you might as well be using NTP. And PTP doesn't support DNS, only IPv4 or IPv6 or Layer 2 MAC addresses. PTP also requires some intelligence with regards to configuring your Ordinary Clocks, your Transparent Clocks, and your Border Clocks. And you have to have these configured on every device in the network path. PTP does have a unicast mode as well as multicast, which can help eliminate unknowable one-way latencies. It's a pain. Check the documentation at https://linuxptp.nwtime.org/documentation/ https://linuxptp.nwtime.org/documentation/ and especially https://linuxptp.nwtime.org/documentation/ptp4l/ https://linuxptp.nwtime.org/documentation/ptp4l/