PTP

This document specifies a transport for the client-server and symmetric modes of the Network Time Protocol (NTP) that encapsulates NTP messages in messages of the Precision Time Protocol (PTP). This transport enables hardware timestamping in network interface controllers (NICs) that can timestamp only PTP messages and delay corrections in PTP transparent clocks.

This document describes a Precision Time Protocol (PTP) Profile (IEEE Standard 1588-2019) for use in an IPv4 or IPv6 enterprise information system environment. The PTP Profile uses the End-to-End delay measurement mechanism, allowing both multicast and unicast Delay Request and Delay Response messages.

The Concise Binary Object Representation (CBOR, RFC 8949) is a data format whose design goals include the possibility of extremely small code size, fairly small message size, and extensibility without the need for version negotiation.

In CBOR, one point of extensibility is the definition of CBOR tags. RFC 8949 defines two tags for time: CBOR tag 0 (RFC 3339 time as a string) and tag 1 (POSIX time as int or float). Since then, additional requirements have become known. The present document defines a CBOR tag for time that allows a more elaborate representation of time, as well as related CBOR tags for duration and time period. This document is intended as the reference document for the IANA registration of the CBOR tags defined.

This document defines a YANG data model for the configuration of devices and clocks using the Precision Time Protocol (PTP) as specified in IEEE Std 1588-2008. It also defines the retrieval of the configuration information, the data sets and the running states of PTP clocks. The YANG module in this document conforms to the Network Management Datastore Architecture (NMDA).

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in internets based on TCP or IP. In particular, it defines objects for managing networks using the Precision Time Protocol (PTP), specified in IEEE Std. 1588-2008.

This memo specifies a MIB module in a manner that is both compliant to the Structure of Management Information version 2 (SMIv2) and semantically identical to the peer SMIv1 definitions.

Clock synchronization protocols are very widely used in IP-based networks. The Network Time Protocol (NTP) has been commonly deployed for many years, and the last few years have seen an increasingly rapid deployment of the Precision Time Protocol (PTP). As time-sensitive applications evolve, clock accuracy requirements are becoming increasingly stringent, requiring the time synchronization protocols to provide high accuracy. This memo describes a multipath approach to PTP and NTP over IP networks, allowing the protocols to run concurrently over multiple communication paths between the master and slave clocks, without modifying these protocols. The multipath approach can significantly contribute to clock accuracy, security, and fault tolerance. The multipath approach that is presented in this document enables backward compatibility with nodes that do not support the multipath functionality.

As time and frequency distribution protocols are becoming increasingly common and widely deployed, concern about their exposure to various security threats is increasing. This document defines a set of security requirements for time protocols, focusing on the Precision Time Protocol (PTP) and the Network Time Protocol (NTP). This document also discusses the security impacts of time protocol practices, the performance implications of external security practices on time protocols, and the dependencies between other security services and time synchronization.

This memorandum describes an engineering model which implements a precision time-of-day function for a generic operating system. The model is based on the principles of disciplined oscillators and phase-lock loops (PLL) often found in the engineering literature. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.