Technical data

304 Appendix D Interfaces
D.1.5 Frames
 Frame Format
Table D.5 displays the frame format used with Fibre Channel.
Table D.5 Frame Format
Start of Frame
(SOF)
Frame Header Data File CRC End of Frame (EOF)
4 bytes 24 bytes 0 to 2112 bytes 4 bytes 4 bytes
Start of Frame:
The Start of Frame (SOF) delimiter is an Ordered Set that immediately precedes the
frame context.
For the types of the SOF, refer to D.1.4).
Frame Header:
The Frame Header is used by the link control facility to control link operations, control
device protocol transfers, and detect missing or out of order frames.
Data Field:
This field can take the following size depending on the frame type. (Note)
Link control frame: Data Field length = 0.
Data frame: Data Field length = 0 to 2112.
The optional header (Note) may be supplied at the top of the Data Field of the data
frame.
The data described in the data frame is Data Field excluding the option header.
This portion is called payload.
Note: The frame type and presence or absence of the optional header are prescribed by
the Frame Header.
CRC:
The CRC is the Cyclic Redundancy Check code for checking data in the Frame Header
and Data Field.
End of Frame:
The End of Frame (EOF) is a frame delimiter for identifying the end of a frame.