Recommendation ITU-T G.9802.1 describes the general requirements for Wavelength Routed ODN based WDM PON. The general architecture and system level requirements, such as line rates, capacity in terms of channel count, OLT and ONU modularity, security, are given. The symmetric nominal line rate combinations of 25 Gbit/s and 10Gbit/s per wavelength channel are supported. The requirements for a range of relevant applications are described in terms of the needed interfaces, physical layer, operation, synchronization, resilience, and protection options. Amendment 1 to Recommendation ITU-T G.9802.1 includes additional requirements on CT, ODN or both failure protection requirements for WRP.