ATOP 20G SFP28-LR is designed for use in 28Gb/s links up to 10Km of G.652 single-mode fiber. Compatible with SFF-8431, SFF-8432, it supports Wireless (CPRI/eCPRI), 25G Ethernet LR and 25G Fiber Channel protocol. It has built-in clock and data recovery (CDR). Digital diagnostic functions are available via an I2C, as specified in SFF-8472 and SFF-8402.