Recommendation ITU-T G.8321 specifies both the components and methodology that should be used in order to specify the metro transport network (MTN) functionality of network elements; it does not specify individual MTN equipment. Amendment 1 adds Annex A, which specifies new atomic functions to align with Amendment 2 to Recommendation ITU-T G.8312, including a new path layer fgMTNP which is above the MTN path, and corrects typos in Figure 9-8 and Figure 9-15. Amendment 2 adds the fgMTNP to CBRx atomic functions and modifies the existing atomic functions to support hitless bandwidth adjustment function. The defect and generic processes are moved from Annex A to clause 6 and clause 8 and the Annex A is restructured.