Converged networks with Fibre Channel over Ethernet and Data Center Bridging

legacy FC ports. Examples of FCFs include HP Virtual Connect FlexFabric modules and HP Networking

5820X top-of-rack access switches with FC option modules.

FCoE has several advantages:

• Uses existing OS device drivers (Because the same vendors make devices used on CNAs and native FC

HBAs, they use a common FC/FCoE driver architecture.)

• Uses the existing Fibre Channel security and management model

• Makes storage targets that are provisioned and managed on a native FC SAN transparently accessible

through an FCoE FCF

However, there are also some challenges with FCoE:

• Must be deployed using a DCB-enabled Ethernet network

• Requires CNAs and new DCB-enabled Ethernet switches between the servers and FCFs (to accommodate

DCB)

• Is a non-routable protocol and used only within the data center. The same is true for native FC protocols

today.

• Requires an FCF device to connect the DCB network to the legacy FC SANs and storage

• Requires validating a new fabric infrastructure that converges LAN communications and FC traffic over

DCB-enabled Ethernet. Validating the network ensures that you have applied proper traffic class

parameters to meet your IT organizations’ business objectives and service level agreements.

Industry transition to converged fabrics

In one-hop architecture, converged traffic goes from a server to a switch that splits it to Ethernet and Fibre

Channel. In two-hop architecture, converged traffic goes to a second switch before the split. The more

switch hops there are in a DCB-enabled network, the more difficult it is to keep the network operating at

peak efficiency while minimizing congestion. Figure 5 shows the expected industry path to convergence.

Figure 5: The expected industry path to convergence leads to multi-hop architectures in 2013.