PTPd is an
open source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...
implementation of the
Precision Time Protocol
The Precision Time Protocol (PTP) is a protocol used to synchronize clocks throughout a computer network. On a local area network, it achieves clock accuracy in the sub-microsecond range, making it suitable for measurement and control systems. ...
for
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
computers.
Derivatives
* ''PTPd'' is a complete, BSD licensed, open source code implementation of the IEEE 1588-2008 PTP specification. Currently only Unix-like computers can run the software, but this essentially means that FreeBSD, Linux, Mac OSX, Minix3 and QNX computers can participate in PTP networks. PTPd can act as a master on a system with an external time source, such as a GPS card, or NTP running as a client.
* ''ptpd2'' was intended to be a complete open source implementation of the IEEE 1588-2008 (PTPv2) PTP specification. The project was abandoned in March 2011.
* ''ptpv2d'' is GPL re-licensed open source code of IEEE 1588 version 1, version 2 and IEEE 802.1AS including hardware timestamping for Freescale MPC831x family of processors.
Accuracy
PTPd accuracy depends on how IEEE 1588 packets are timestamped on the participating machines. When IEEE 1588 packets are timestamped in software, interrupt latency, OS scheduling, and other software issues reduce the accuracy of the acquired timestamps, and therefore, the accuracy of time synchronization. The presence of
hardware-assisted timestamping makes it possible to acquire more precise send and receive timestamps. A test in 2010 on an Intel Gigabit
network card
A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network.
Ear ...
noted offset converging to varying between around 1–100 microseconds in a pure software implementation, and to around a microsecond when using hardware-assisted PTP.
See also
*
List of PTP implementations
Precision Time Protocol (PTP) is a widely adopted protocol for delivery of precise time over a computer network. A complete PTP system includes PTP functionality in network equipment and hosts. PTP may be implemented in hardware, software or a com ...
References
External links
*{{official website, github.com/ptpd
Network time-related software