本标准定义了一种网络协议，能够准确、精确地同步网络分布式系统中设备的实时时钟。该协议适用于设备通过网络（包括以太网）进行通信的系统。该标准允许多播通信、单播通信或两者兼有。该标准规定了将协议映射到特定网络实现的要求，并定义了此类映射，包括用户数据报协议（UDP）/互联网协议（IP版本4和6）以及第二层IEEE 802.3以太网。 该协议使包含各种固有精度、分辨率和稳定性的时钟的异构系统能够与主时钟同步。 该协议支持亚微秒范围内的同步，且网络带宽和本地时钟计算资源最少。该协议将同步支持提高到1纳秒以上。协议规定了如果已知不对称值，如何对路径不对称进行校正。如果需要可追溯到国际标准或其他时间来源的时间，则可以将特级大师同步到系统外部的时间来源。如果grandmaster可追溯到国际标准，并且能够访问待定的闰秒更改，则该协议为设备提供信息，以根据协议分配的时间计算协调世界时（UTC）。 还提供了允许终端设备从协议分布式时间尺度计算其他时间尺度的选项。 该协议定义了系统定时一致的定时域。该协议建立了定时拓扑。协议的默认行为允许安装和操作简单的系统，而无需用户的管理关注来确定系统定时拓扑。 该标准定义了所有需要的数据类型、消息格式、所需的计算、内部状态、设备在传输、接收和处理协议通信方面的行为。该标准规定了设备中协议工件的管理。 该标准定义了消息扩展的正式机制，以及允许为特定应用程序域定制的概要文件的要求。 该标准定义了一致性要求。为协议安全性提供可选规范。本标准记录了本标准与IEEE 1588-2008向后兼容的条件。

This standard defines a network protocol enabling accurate and precise synchronization of the real-time clocks of devices in networked distributed systems. The protocol is applicable to systems where devices communicate via networks, including Ethernet. The standard allows multicast communication, unicast communication or both. The standard specifies requirements for mapping the protocol to specific network implementations and defines such mappings, including User Datagram Protocol (UDP)/Internet Protocol (IP versions 4 and 6), and layer-2 IEEE 802.3 Ethernet. The protocol enables heterogeneous systems that include clocks of various inherent precision, resolution, and stability to synchronize to a grandmaster clock. The protocol supports synchronization in the sub-microsecond range with minimal network bandwidth and local clock computing resources. The protocol enhances support for synchronization to better than 1 nanosecond. The protocol specifies how corrections for path asymmetry are made, if the asymmetry values are known. The grandmaster can be synchronized to a source of time external to the system, if time traceable to international standards or other source of time is required. The protocol provides information for devices to compute Coordinated Universal Time (UTC) from the protocol distributed time, if the grandmaster is traceable to international standards and is able to access pending leap second changes. Options are also provided to allow end devices to compute other time scales from the protocol distributed time scale. The protocol defines timing domains in which system timing is consistent. The protocol establishes the timing topology. The default behavior of the protocol allows simple systems to be installed and operated without requiring the administrative attention of users to determine the system timing topology. The standard defines all needed data types, message formats, required computations, internal states, the behavior of devices with respect to transmitting, receiving, and processing protocol communications. The standard provides for the management of protocol artifacts in devices. The standard defines formal mechanisms for message extensions and the requirements for profiles that allow customization for specific application domains. The standard defines conformance requirements. Optional specifications are provided for protocol security. This standard documents conditions under which this standard is backward compatible with IEEE 1588-2008.