Deployment Guide
Figure 130. Case 2: Deployment Scenario of Conguring FC Flex IO Modules
Data Center Bridging (DCB)
Data center bridging (DCB) is supported on the FC Flex IO module installed in the FN IOM.
Ethernet Enhancements in Data Center Bridging
The following section describes DCB.
• The device supports the following DCB features:
• Data center bridging exchange protocol (DCBx)
• Priority-based ow control (PFC)
• Enhanced transmission selection (ETS)
DCB refers to a set of IEEE Ethernet enhancements that provide data centers with a single, robust, converged network to support multiple
trac types, including local area network (LAN), server, and storage trac. Through network consolidation, DCB results in reduced
operational cost, simplied management, and easy scalability by avoiding the need to deploy separate application-specic networks.
For example, instead of deploying an Ethernet network for LAN trac, include additional storage area networks (SANs) to ensure lossless
Fibre Channel trac, and a separate InniBand network for high-performance inter-processor computing within server clusters, only one
DCB-enabled network is required in a data center. The Dell Networking switches that support a unied fabric and consolidate multiple
network infrastructures use a single input/output (I/O) device called a converged network adapter (CNA).
A CNA is a computer input/output device that combines the functionality of a host bus adapter (HBA) with a network interface controller
(NIC). Multiple adapters on dierent devices for several trac types are no longer required.
Data center bridging satises the needs of the following types of data center trac in a unied fabric:
LAN
trac LAN trac consists of many ows that are insensitive to latency requirements, while certain applications, such as
streaming video, are more sensitive to latency. Ethernet functions as a best-eort network that may drop packets
in the case of network congestion. IP networks rely on transport protocols (for example, TCP) for reliable data
transmission with the associated cost of greater processing overhead and performance impact.
Storage trac Storage trac based on Fibre Channel media uses the SCSI protocol for data transfer. This trac typically consists
of large data packets with a payload of 2K bytes that cannot recover from frame loss. To successfully transport
storage trac, data center Ethernet must provide no-drop service with lossless links.
946 FC Flex IO Modules