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: Profile isolation
Five Minute Facts About Packet Timing Next in the series on What is in the 2019 edition of IEEE 1588 is profile isolation. And while we are looking at that we will take a peak at the PTP common message header, the part of PTP message which has the same structure regardless of which PTP […]
What’s in the 2019 edition of 1588: Slave port monitoring
Five Minute Facts About Packet Timing By Doug Arnold Next in the series on What is in the 2019 edition of IEEE 1588 is slave port monitoring, also known as slave event monitoring. Sometimes it is not enough to transfer time accurately from a PTP Grandmaster (GM) to a PTP Slave (slave). Sometimes you also […]
PTP Timescale (and what the heck is Arb time?)
Five Minute Facts About Packet Timing By Doug Arnold Most application which use PTP to distribute time, don’t actually need standard time, as understood by national laboratories. All that is needed is for the clocks in a network to have the same time. However, there are several reasons to use a standard timescale when distributing […]
What’s in the IEEE 1588 revision: Interdomain interactions
Five Minute Facts About Packet Timing By Doug Arnold The next installment in what’s in the revision of IEEE 1588 discusses PTP domains Before we get started. A quick review on domains. Every PTP message contains a domain number. A PTP instance is configured to work in one, and only one, domain. It is required […]
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 […]
HSR and PRP: redundant Layer 2 networks
Five Minute Facts About Packet Timing By Doug Arnold If are looking into network technologies for power substations, or industrial automation you may run across HSR and/or PRP. So here is the five-minute version of what these things are. First of all, both HSR and PRP are layer s network protocols, which have include the […]
The virtues of clock watching: Why it’s important to monitor your timing network
Five Minute Facts About Packet Timing By Doug Arnold A network architect’s job is never done. It is not enough to design the network, and see that design implemented. You need to keep checking to make sure that everything still works as the network evolves. It’s certainly true for your network-based timing system. First remember […]