This Recommendation specifies a profile for telecommunication applications based on [IEEE 1588] precision time protocol (PTP). The profile specifies the [IEEE 1588] functions that are necessary to ensure network element interoperability for the delivery of frequency only. The profile is based on the architecture described in [ITU-T G.8265] and definitions described in [ITU-T G.8260]. The first version of the profile specifies the high-level design requirements, modes of operation for the exchange of PTP messages, the PTP protocol mapping, the use of unicast transmission and negotiation, an alternate best master clock algorithm (BMCA), as well as the PTP protocol configuration parameters. The support for mixed unicast/multicast or static unicast modes is for further study.

This Recommendation also specifies some aspects necessary for use in a telecom environment which are outside the scope of, and complement the PTP profile.

An implementation compliant with this profile can claim compliance with either IEEE Std 1588-2008 [IEEE 1588-2008] or IEEE Std 1588-2019 [IEEE 1588-2019]. Considerations on the use of one or the other profile are provided in Appendix III. Compliance for a specific implementation with either the [IEEE 1588-2008] or [IEEE 1588-2019] versions of the standard should be stated when referring to this profile.