H3C Technologies H3C S12500-X Series Switches - Manual (Page 12)

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Figure 2 Structure of an FC address
A Domain_ID can uniquely identify an FC switch. Different FC 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. FC switches use Domain_IDs to route messages between each other.
The FC protocol standardizes the FC address usage. For more information, see "
Appendixes ."
Port modes
In a switched fabric, nodes and FC switches communicate through interfaces of different modes.
Figure 3 Port modes
• A node supports the following port modes:
{
N_Port—Directly connects to a fabric.
{
NL_Port—Connects to a fabric through an arbitrated loop.
• An FC switch provides the following port modes:
{
F_Port—Connects to an N_Port or an NP_Port on another FC switch.
{
E_Port—Connects to an E_Port on another FC switch.
{
NP_Port—Connects to an F_Port on another FC switch. For more information about NP_Port,
see "
Configuring NPV ."
E_Ports connect FC switches to form a fabric, and F_Ports connect the nodes to FC switches in the
fabric.
Communication flow
FC switches provide data transmission services. Through FC switches, a server sends instructions and
data to disk devices and reads data from disk devices.