Contents
Does PTP require special hardware?
The three main components are: a GPS Grandmaster clock, an Ethernet switch (transparent or boundary clock), and a PTP slave. All components must support hardware timestamping.
What is PTP hardware timestamp?
The timestamp is generated using the NIC’s own hardware clock. This feature is used in particular by the Precision Time Protocol (PTP), which is a time synchronization protocol. PTP makes provision to use such hardware timestamps within the protocol itself.
What is PTP hardware?
Precision time protocol (PTP) is used to synchronize clocks within a computer network. Specifically, the master-slave relationship used for synchronized clocks in a PTP network can be established by software running on a master computer and slave computers networked together.
What is a PTP application?
The PTP (Precision Time Protocol) client sample application is a simple example of using the DPDK IEEE1588 API to communicate with a PTP master clock to synchronize the time on the NIC and, optionally, on the Linux system. Note, PTP is a time syncing protocol and cannot be used within DPDK as a time-stamping mechanism.
What is the difference between PTP and gPTP?
In the case of Ethernet, gPTP uses a complete IEEE 1588-2008 profile, known as Precision Time Protocol (PTP) [4]. However, gPTP has some features that go beyond PTP. Compared to PTP, gPTP is much more robust against delay variations as it demands that every switch in the network supports gPTP at the MAC layer.
How does PTP protocol work?
IEEE 1588 PTP (Version 2) clock synchronization standard is a highly precise protocol for time synchronization that synchronizes clocks in a distributed system. The time synchronization is achieved through packets that are transmitted and received in a session between a primary clock and a client clock .
What port does PTP use?
UDP ports 319
PTP encapsulation over UDP over IP—PTP uses UDP as the transport protocol over IP. In both, the unicast and multicast modes, PTP uses UDP ports 319 for event messages and 320 for general messages communication between devices.
What is gPTP protocol?
The gPTP protocol must be used for time synchronization between the SoC and AURIX. gPTP is part of the Audio Video Bridging (AVB) Standard: IEEE 802.1AS: Timing and Synchronization for Time-Sensitive Applications (gPTP). On the platform, gPTP over Ethernet is used for time synchronization.
Is PTP UDP or TCP?
PTP supports transport over User Datagram Protocol (UDP). Transport over Ethernet is not supported. PTP supports multicast communication.
Can a transmitter be hardware time stamped with PTP?
I can only get the packets to be hardware time stamped at the receiver when the transmitter could build packets with PTP. But I think my micro-controller API’s do not have that support for PTP.
Are there Ethernet devices that support hardware timestamping?
All of their Ethernet devices can support hardware timestamping as well as an unnamed PTP master whose configuration is beyond the scope of this guide. When dealing with hardware clocks, it is necessary to enable support for them in the kernel.
How does the Precision Time Protocol ( PTP ) work?
The Precision Time Protocol, as defined in the IEEE-1588 standard, provides a method to precisely synchronize computers over a Local Area Network (LAN). PTP is capable of synchronizing multiple clocks to better than 100 nanoseconds on a network specifically designed for IEEE-1588.
How does Chrony use Nic clock for timestamping?
The xleave option gets used everywhere there is a peer that has PTP support. That will cause chrony to use the NIC clock to hardware timestamp the ethernet traffic it uses with the other host to update the clock. This helps to reduce jitter and improve accuracy.