Fc Protocol; Basic Concepts - HP 5920 series Configuration Manual

FC protocol

The servers, FCF switches, and disk devices in an FC SAN must all support FC.

Basic concepts

WWN
The World Wide Name (WWN) is a 64-bit address that identifies a fabric or an entity (such as an FCF
switch, node, or port) in an FC SAN. The upper-layer protocol of FC uses WWNs for communication.
Each entity has a factory-assigned globally unique WWN.
FC address
The FC protocol accesses communication entities in a SAN through FC addresses. An FC address is also
known as an "FC_ID."
Figure 2 shows the structure of an FC address. The FC address is 24 bits long and is divided into these
8-bit fields: Domain_ID, Area_ID, and Port_ID.
A domain represents a switch and all N_Ports connected to the switch. A Domain_ID, which is in the
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range of 1 to 239, uniquely identifies an FCF switch.
One or more N_Ports on the same node can be assigned to an area, which is identified by an
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Area_ID.
The Port_ID field identifies an N_Port.
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Figure 2 Structure of an FC address
A Domain_ID can uniquely identify an FCF switch. Different FCF switches in the same fabric have
different Domain_IDs.
An FC address can uniquely identify an N_Port on a node. Different N_Ports on the same node have
different FC addresses. FCF switches use Domain_IDs to route messages between each other.
The FC protocol standardizes the FC address usage. For more information, see "Appendixes."
Interface modes
In a switched fabric, nodes and FCF switches communicate through interfaces of different modes.
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