Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 245

dcb-map linecard 0 backplane all dcb-map linecard all backplane all NOTE: Dell Networking OS Behavior: DCB is not supported if you enable link-level flow control on one or more interfaces. For more information, refer to Ethernet Pause Frames. 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 flow control (PFC) • Enhanced transmission selection (ETS) NOTE: DCB is not supported on the Port Extender ports and Cascade ports. 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: LAN traffic Storage traffic InterProcess Communication (IPC) 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 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 nodrop service with lossless links. InterProcess Communication (IPC) traffic within high-performance computing clusters to share information. Server traffic is extremely sensitive to latency requirements. 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) Data Center Bridging (DCB) 245