Fibre Channel Protocol Architecture
ULP Information Transfer
FC-3 Common Services FC-3 Common Services
FC-2 Framing and flow control FC-2 Framing and flow control
FC-1 Encoding FC-1 Encoding
FC-0 Physical interface FC-0 Physical interface
Fibre Channel information passing is a symmetric operation:
Native information (e.g. SCSI commands) are processed by the driver
and then handed to the FC-4 layer for conversion to Information Units
IUs contain “chunks” which are passed down through FC-3 to FC-2 with
a request to transport them to their destination.
FC-2 packages “chunks” into frames and sequences and then passes to
FC-1 and FC-0 which transmits them along the link to the receiving port.
The receiving port performs a reverse of this process to deliver native
information to the associated driver.