#NTP #PTP #NetworkTiming #Meinberg

Why it’s important to monitor your timing network

There are basically three levels of network time monitoring:

1. Self-reported performance

Of these, number 1, self-reporting is the easiest. Nearly every device which includes a PTP slave or an NTP client has management interfaces which can report on the timing applications synchronization state and estimate of the time offset from the NTP server or PTP master. Most likely you have something more urgent to attend to than staring at the offset values of all of the clocks on your network. But you can set up notifications, for example SNMP traps, if a device loses its synchronization source, or is seeing larger than expected time offsets. Because this is easy and will catch many network synchronization problems, you should definitely do this.

An NTP client or PTP slave doesn’t necessarily know the correct value for its clock offset. That’s because of Asymmetry. Asymmetry it the bane of network time transfer. Both NTP and PTP assume that the network propagation delay for forward and reverse message transfer is the same. That is client to server and server to client in NTP; and master to slave, and slave to master in PTP.