Amendment 3 to Recommendation ITU-T G.7041/Y.1303 (2011) adds payload types and mapping descriptions associated with GFP encapsulation of two types of synchronization messages. The first type of synchronization message is the Precision Time Protocol message, used to provide time and phase synchronization. The second message type is the Synchronization Status Message, which provides information regarding the quality of the clock source being used by the SSM source.