port identification (FC) (Port_ID)
In Fibre Channel( FC), the port identification(Port_ID) is a uniquely occurring hierarchically structured 24-bit address.
The port identification is composed of an 8-bit domain ID, usually the switch number, an 8-bit area ID for a port or the port group of a switch port, and an 8-bit device ID. The port ID of the source port (S_ID) and the port ID of the destination port( D_ID) are transmitted in the FC data frame for routing.