Dell S4048T Configuration Manual page 294

• 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
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.
InterProcess InterProcess Communication (IPC) traffic within high-performance computing clusters
Communication to share information. Server traffic is extremely sensitive to latency requirements.
(IPC) traffic
To ensure lossless delivery and latency-sensitive scheduling of storage and service traffic and I/O
convergence of LAN, storage, and server traffic over a unified fabric, IEEE data center bridging adds the
following extensions to a classical Ethernet network:
• 802.1Qbb — Priority-based Flow Control (PFC)
• 802.1Qaz — Enhanced Transmission Selection (ETS)
Sample DCB Configuration
Data Center Bridging (DCB)
for the CLI configurations.
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