H3C Technologies H3C S12500-X Series Switches - Manual (Page 10)

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FCoE overview
The switch supports FCoE only when operating in advanced mode. For more information about system
operating modes, see Fundamentals Configuration Guide.
In an FCoE network, H3C recommends that you set the delay for the IRF ports to report a link down event
as 0 on IRF member devices. For more information, see the irf link-delay command in Fundamentals
Command Reference.
If a switch is connected to a server or storage device with a converged network adapter (CNA), you must
also configure DCBX on the connecting Ethernet interface. For information about configuring DCBX, see
Layer 2—LAN Switching Configuration Guide.
Storage area network
According to the Storage Networking Industry Association dictionary, "a storage area network (SAN) is
any high-performance network whose primary purpose is to enable disk devices to communicate with
computer systems and with each other."
A SAN enables the universal connectivity of servers and disk devices. Compared to the conventional
client/server computer system, a SAN allows the servers to share data and directly access data created
by one another without having to copy it, improves storage scalability, and centralizes the management
of data backup, access, and security.
Most SANs use Fibre Channel (FC) or Ethernet to interconnect devices. An FC SAN uses the FC protocol
suite for communication, and an Ethernet SAN uses the TCP/IP protocol suite for communication.
This document covers only the FC SAN.
FC SAN
As shown in Figure 1 , an FC SAN connects the data sending and receiving entities (network servers and
disk devices) with fibers or copper wires in the following ways:
• Directly connects a server and a disk device, as shown in the point-to-point connection.
• Connects servers and disk devices to an FC switched fabric, as shown in the switched fabric. In a
switched fabric, the servers and disk devices are called "nodes." A fabric uses 24-bit addressing
and supports thousands of devices.