Five-minute facts about packet timingOnce upon a time there was an industry that needed data sharing and time synchronization among devices that were spatially disbursed. So, the industry developed standards for data transfer and timing signals that … [Continue reading]
BMCA Deep Dive: Part 2
Five-minute facts about packet timing This is part 2 of a two-part description of the Best Master Clock Algorithm (BMCA). In Part 1 we listed the information that is considered in the BMCA and what the priorities are amongst those … [Continue reading]
BMCA deep dive: part 1
Five-minute facts about packet timingI previously posted about the Best Master Clock Algorithm or BMCA. Nevertheless, this aspect of the Precision Time Protocol (PTP) continues to stimulate questions from equipment designers and network operators. … [Continue reading]
Network Time Security (NTS): Updated security for NTP
Five-minute facts about packet timingNetwork Time Protocol version 4 (RFC 5905) is a spectacularly successful network time transfer protocol. It can be found in almost every IP network. Often NTP messages will traverse leased lines or the “public … [Continue reading]
Implementing PRP devices and networks
5 minute facts about packet timingIn a previous post I talked about the new redundant networking protocols High Availability Seamless Redundancy (HSR) and Parallel Redundancy Protocol (PRP). These protocols are defined in the IEC 62439-3 standard. … [Continue reading]
The Root of All Timing: Understanding root delay and root dispersion in NTP
Five Minute Facts About Packet Timing If you examine an NTP packet you will see the fields root delay and root dispersion. See the diagram from RFC 5905 in Figure 1 bellow, which defines NTP version 4, the current version. You might ask … [Continue reading]
Unicast Master Port Selection in PTP: When should a slave port swipe right
Five Minute Facts About Packet TimingIn multicast PTP a slave port need only subscribe to the PTP multicast addresses and timing will come to it. However, in unicast PTP a slave port has to reach out to the master port it wants time from with PTP … [Continue reading]
What’s new in IEEE 1588-2019: L1 Sync
Five Minute Facts About Packet Timing Time to play what's new in IEEE 1588-2019, the game where everyone wins new PTP features. L1 Sync is short for physical layer frequency synchronization. Recall that frequency sync is also referred to … [Continue reading]
What’s in IEEE 1588-2019: DIY PTP Port States
Five Minute Facts About Packet TimingIn this installment of What’s in IEEE 1588-2019 we look at the exciting and dangerous world of manual port state configuration1. The Best Master Clock Algorithm leaving you uninspired? No longer a problem, you … [Continue reading]
PTP Auto Mode
Five Minute Facts About Packet Timing By Andreja Jarc. In this post I would like to introduce a method which can be deployed in versatile PTP networks, professional media, power or any other timing network. Basically, it is a method which … [Continue reading]