This amendment continues the maintenance and evolution of OMCI as defined in Recommendation ITU-T G.988 (2010). In addition, it defines TC-layer PM for XG-PON in accordance with G.987.3, extends OMCI to cover wider multicast use cases, extends the support of IPv6 and defines optional extensions to OMCI messages, in particular those related to testing. Finally, G.988 is adapted to support IEEE 802.3 PON access networks.