Fibre Channel Frame Header – Understanding Data and Payload Fields

fiber

The confusing image

I came across this image of a FC frame header. I see that there are two fields, a 2112 byte data field and a 2048 byte payload field. I tried to read about how to distinguish among the two, but ended up being more confused. Some links mention that the maximum data that can be transferred per frame is 2112 bytes, while other sources mention it is 2048 bytes, which makes me feel that these fields are both used for payload delivery somehow.

Please help. Thank you.

Best Answer

Notice that the Payload is part of the Data Field. The only difference is that you can have an optional header, otherwise the Data Field and Payload are the same field, with the same length.