Deployment Guide

Data Center Bridging (DCB)
Data center bridging (DCB) refers to a set of enhancements to Ethernet local area networks used in data center environments,
particularly with clustering and storage area networks.
Topics:
• Ethernet Enhancements in Data Center Bridging
• Enabling Data Center Bridging
• Data Center Bridging: Default Configuration
• Configuring Priority-Based Flow Control
• Configuring PFC in a DCB Map
• Applying a DCB Map on a Port
• Configuring PFC without a DCB Map
• Configuring PFC Asymmetric
• Priority-Based Flow Control Using Dynamic Buffer Method
• Shared headroom for lossless or PFC packets
• Behavior of Tagged Packets
• SNMP Support for PFC and Buffer Statistics Tracking
• Performing PFC Using DSCP Bits Instead of 802.1p Bits
• Configuration Example for DSCP and PFC Priorities
• Using PFC to Manage Converged Ethernet Traffic
• Generation of PFC for a Priority for Untagged Packets
• Configure Enhanced Transmission Selection
• Hierarchical Scheduling in ETS Output Policies
• Using ETS to Manage Converged Ethernet Traffic
• Applying DCB Policies in a Switch Stack
• Configure a DCBx Operation
• Verifying the DCB Configuration
• QoS dot1p Traffic Classification and Queue Assignment
• Configuring the Dynamic Buffer Method
• Sample DCB Configuration
Ethernet Enhancements in Data Center Bridging
The following section describes DCB.
The device supports the following DCB features:
● Priority-based flow control (PFC)
● Enhanced transmission selection (ETS)
To configure PFC, ETS, and 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 EMC 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.
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