Recommendation ITU-T G.8264 outlines aspects of distribution of timing information through packet networks and initially focuses on Ethernet networks. A number of methods may be used to transfer frequency which may be physical-layer based or protocol-layer based. This Recommendation provides information on architectural aspects of timing flows in Ethernet networks which will form the basis for future work related to time and phase transfer. This Recommendation specifies the synchronization status message (SSM) protocol and formats for use with synchronous Ethernet. Adherence to the SSM formats specified in this Recommendation is required in order to ensure interoperability between synchronous Ethernet equipment involved in frequency transfer. This revision of ITU-T G.8264 includes the following changes: • Move the contents of clause 11.3.1.2, 11.3.1.3 to ITU-T G.781, and add a reference to ITU-T G.781. • Move the contents of clause 11.6 to ITU-T G.781, and add a reference to ITU-T G.781. • Move the contents of annex A.7 to ITU-T G.781, and add a reference to ITU-T G.781. • Replace the reference of [IEEE 802.3] with [ITU-T G.8020.3]. • Add some clarification into clause 11.1.1 about synchronization over LAG.