cmHSSICRC is a read-write enumeration configuring the CRC format used for error checking on frames sent and received over the HSSI-WAN module, though the description notes only crc-16(2) is currently supported. An administrator sets this to match the CRC format expected by the connected far-end equipment, though on this hardware there is effectively only one valid choice. For example, an operator configuring a new HSSI circuit would still explicitly set cmHSSICRC to crc-16 to ensure the setting is not left at an unsupported or undefined value.