The blinking box on your wall is a slow optical module. The 800G ones filling switch faceplates in an AI cluster are the same symmetric signal chain, just run a few dozen times faster.

你家墙上一闪一闪的光猫就是一只低速光模块。从光猫到数据中心里插满面板的 800G 模块，拆开看是同一条对称的信号链。