The flexible, multi-protocol MSH221 PHY device supports a total of 8 independent SerDes lanes with data rate flexibility including 10-15G and 25-28G. For 100GE (4x25G) support, the device supports optional RS-FEC specified in 802.3bj Clause 91 for 4x25G NRZ interfaces. When the RS-FEC is turned off, the MSH221 device functions as a standard multi-rate and multi-protocol retimer capable of passing data whether encoded or non-encoded.

Each lane is independent and can support a broad range of frequencies compatible with 10G, 25G, 40G and 100G Ethernet and OTN standards. With the 100G 802.3bj RS-FEC encode, decode and correction functions enabled, the device will encode data from A Side to B Side and decode and correct data (if needed) in the other direction. The IEEE 802.3bj RS-FEC enables additional signal integrity and/or distance capability over optical or copper interconnects and has been specified in multiple standards and MSAs including SR4, CWDM4 and PSM4.