Recommendation ITU-T G.997.1 specifies the physical layer management for asymmetric digital subscriber line (ADSL) and very high speed digital subscriber line 2 (VDSL2) transmission systems. It specifies means of communication on a transport transmission channel defined in the physical layer Recommendations ITU-T G.992.1, ITU-T G.992.2, ITU-T G.992.3, ITU-T G.992.4, ITU T G.992.5 and ITU-T G.993.2. It specifies network elements (NE) content and syntax for configuration, fault and performance management. The revision of this Recommendation includes the management information base (MIB) elements for the physical layer management of Recommendation ITU T G.993.2 and additional MIB elements for the physical layer management of Recommendations ITU T G.992.3 and ITU-T G.992.5. The 2018 edition of this Recommendation integrates ITU-T G.997.1 (2016) and all its amendments and corrigenda. It adds the following new technical material: -Add support for G.993.2 Annex N PSD masks. -Add support of MAXEFTR and extend the definition of the parameters "error-free bits counter" and "MINEFTR" to apply to line with retransmission inactive. New material is indicated with change bars.