In this article, Cathy Liu discusses how channel error models and FEC performance analysis have been updated according to industry changes, as well as how different Ethernet coding schemes have been studied and simulated for 800GE and 1.6GE systems with 200 Gbps per lane. Liu investigates concatenated FEC with soft-decision decoding for inner code to protect 200 Gbps optical link and the effect of different FEC options on system SI.