H3C Technologies H3C S12500-X Series Switches - Manual (Page 11)

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Figure 1 FC SAN networking
NOTE:
•
An FC SAN refers to a network comprising FC switches and nodes.
• A fabric refers to a transmission network comprising FC switches.
FC protocol
The servers, FC 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 FC
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
range of 1 to 239, uniquely identifies an FC switch.
• One or more N_Ports on the same node can be assigned to an area, which is identified by an
Area_ID.
• The Port_ID field identifies an N_Port.