Five Minute Facts About Packet Timing By Doug Arnold. If you are new to the exciting world of IEEE 1588, or even if you are not, you might find yourself confused by all of the different types of clocks. I’ve heard and seen the following terms used related to PTP:
Search Results for: what are all these clock types
IEEE 1952 PNT Resilience Levels: Detecting Adversities
Five Ten Minute Facts about Packet Timing (sorry this one needs to be a little longer)In my last post I talked about the behaviors that timing equipment should exhibit to achieve resilience in the face of adverse conditions, according to the draft standard IEEE P1952. One of these is the ability to detect an adversity […]
What is gPTP?
Five-minute facts about packet timing gPTP is the name given to the IEEE 802.1AS profile of PTP. gPTP is only sort of a PTP profile. That is because gPTP is independently specified. In other words, rather than stating that it requires, forbids, and allows certain options defined in IEEE 1588, it specifies all these features […]
What happened at the last ISPCS PTP Plugfest
Five Minute Facts about Packet Timing After three years off for the pandemic, which felt like thirty, the ISPCS has been meeting in person again. In Vienna in 2022, London in 2023, and this year it will be in Tokyo in October. The ISPCS is the International Symposium on Precision Clock Synchronization. It’s a workshop […]
BMCA deep dive: part 1
Five-minute facts about packet timing I 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. So, I will attempt to describe it in more detail, which will be spread over two posts. In this post […]
Implementing PRP devices and networks
5 minute facts about packet timing In 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. Today I want to talk in more detail about PRP devices and networks. Recall that a PRP network […]
The Sync Monitor reverse PTP mechanism
Five Minute Facts About Packet Timing By Doug Arnold Since timing is a critical component of many networked systems, there is a desire among network operators to measure the time distribution performance in their networks. This includes logging time compliance for regulations such as MiFID II, as well as well as for general performance monitoring. To […]
TLVs in PTP Messages
Five Minute Facts About Packet Timing By Doug Arnold What is with al of these TLVs in the Precision Time Protocol?Let’s start at the beginning, TLV stands for “type, length, value.” It is a general means to extend a PTP message with some extra information for some optional feature or whatever. TLVs are used in many […]
What’s in the 2019 edition of IEEE 1588: Performance Monitoring
Five Minute Facts About Packet Timing By Doug Arnold Every implementation of PTP includes some information about the state and performance of the device. So in principle a monitoring node could gather all the data and determine the health of the PTP network. Here’s the rub: If you’re the poor soul who is writing the code […]
What’s in the 2019 edition of IEEE 1588: Mixed Multicast Unicast Operation
Five Minute Facts About Packet Timing By Doug Arnold The next installment in what’s in the revision of IEEE 1588 discusses mixed multicast-unicast operation. In a previous post I described the virtues of mixed multicast-unicast operation in PTP. Sometimes this is referred to as the “hybrid mode”. I summarize the conclusion here, but if you […]