Dell S4048-ON, Configuration Manual

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Data Center Bridging (DCB)
Ethernet Enhancements in Data Center Bridging
The following section describes DCB.
The S4048–ON system supports loading two DCB_Config files: FCoE_DCB_Config and iSCSI_DCB_Config .
These files are located in the root directory flash:/CONFIG_TEMPLATE. After copying the configuration files to the startup config
and reloading the system.
The device supports the following DCB features:
• Data center bridging exchange protocol (DCBx)
• Priority-based flow control (PFC)
• Enhanced transmission selection (ETS)
To configure PFC, ETS, and DCBx for DCB, refer to Sample DCB Configuration for the CLI configurations.
DCB refers to a set of IEEE Ethernet enhancements that provide data centers with a single, robust, converged network to support
multiple traffic types, including local area network (LAN), server, and storage traffic. Through network consolidation, DCB results in
reduced operational cost, simplified management, and easy scalability by avoiding the need to deploy separate application-specific
networks.
For example, instead of deploying an Ethernet network for LAN traffic, include additional storage area networks (SANs) to ensure
lossless Fibre Channel traffic, and a separate InfiniBand 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 unified 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 different devices for several traffic types are no longer required.
Data center bridging satisfies the needs of the following types of data center traffic in a unified fabric:
Traffic Description
LAN traffic LAN traffic consists of many flows that are insensitive to latency requirements, while certain applications,
such as streaming video, are more sensitive to latency. Ethernet functions as a best-effort 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 LAN traffic consists of a large number of flows that are generally insensitive to latency requirements,
while certain applications, such as streaming video, are more sensitive to latency. Ethernet functions as a
best-effort network that may drop packets in 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 traffic Storage traffic based on Fibre Channel media uses the Small Computer System Interface (SCSI) protocol for
data transfer. This traffic typically consists of large data packets with a payload of 2K bytes that cannot
recover from frame loss. To successfully transport storage traffic, data center Ethernet must provide no-
drop service with lossless links.
Data Center Bridging (DCB)
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