This standard describes a set of technical additions and clarifications to INCITS 466-2011, Fibre Channel - Single-Byte Command Code Sets - 4 Mapping Protocol (FC-SB-4) to define enhancements to the link-control and transport-mode protocols to expand the capabilities and increase the efficiency of transport-mode operations.

It also includes changes required, technical or otherwise, for issues related to the current FC-SB-4 protocol as deemed necessary by the working group.

This standard describes a communication interface between a channel and I/O control units that utilize the Single-Byte Command Code Sets (SBCCS) as implemented in a wide range of data processing systems. It employs information formats and signaling protocols that provide a uniform means for communicating with various types of I/O control units, facilitating a high-bandwith, high-performance, and long-distance information exchange environment.

This standard modifies the FC-SB-4 standard, which defined the transport mode of operation, to specify enhancements to the transport-mode protocols to increase the efficiency and expand the capabilities of transport-mode operations. Additionally, link-control protocols are defined that utilize new control-unit discovery protocols that enhance the I/O configuration and link initialization process.