March 2013 Dell EqualLogic Configuration Guide v14.1 14-127
the same physical infrastructure to increase operational efficiency, constrain costs, and ease network
management.
There are primarily three progressive versions of DCB:
• Cisco, Intel, Nuova (CIN) DCBX
• Converged Enhanced Ethernet (CEE) DCBX or baseline DCBX
• Institute of Electrical and Electronic Engineers (IEEE) DCB.
DCB technologies based on standards include:
• PFC – Priority based Flow Control (802.1Qbb)
• ETS – Enhanced Transmission Selection (802.1Qaz)
• CN – Congestion Notification (802.1Qau)
• DCBx – Data Center Bridging Capability eXchange
• Support for iSCSI application protocol priority with DCBX (also known as iSCSI TLV)
Note: DCB uses 10Gb and higher Ethernet only.
I/O convergence using DCB for Dell EqualLogic iSCSI storage is the future direction for “Converged
iSCSI” in a lossless Ethernet environment.
Without DCB, it is typical to dedicate a separate physical network infrastructure for SAN traffic to
guarantee the infrastructure for bandwidth and performance as shown in the figure below. For iSCSI, it
is a best practice to dedicate a SAN comprised of Ethernet switches for server and storage inter-
connection. In this case, the server and storage systems are configured with dedicated NICs to
communicate on the iSCSI SAN.
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