HP ProLiant DL185 10 Gigabit Ethernet technology for industry-standard servers - Page 4

(iSCSI) is a standard that implements the SCSI protocol over IP networks to enable connectivity with storage devices. The self-titled section later in this paper provides more details about iSCSI. Ethernet Ethernet is the most well-established of the interconnects and is utilized for IP-based communications such as email, web browsing, management, Voice Over Internet Protocol (VOIP), VOD, and iSCSI. IP networks continue to be the most pervasive fabric found in most business environments. Fibre Channel Fibre Channel (FC) is a gigabit to multi-gigabit-speed storage network technology that has become the standard connection type for SANs in enterprise storage. Contrary to its name, FC can run on both copper wire and fiber-optic cables. The Fibre Channel Protocol (FCP) is similar to the Transmission Control Protocol (TCP) used in IP networks and commonly transports SCSI commands over FC networks. InfiniBand InfiniBand is a switched-fabric communications link primarily used in HPC. Its features include quality of service (QoS) and failover, and it is designed to be low-latency, high-bandwidth, and scalable. The InfiniBand architecture specification defines a connection between processor nodes and high performance I/O nodes such as storage devices. Like Fibre Channel, PCI Express, Serial ATA, and many other modern interconnects, InfiniBand is a point-to-point bidirectional serial link intended for connecting processors with high-speed peripherals such as disks. It supports several signaling rates and links can be aggregated for additional bandwidth. InfiniBand is useful in environments where performance demands are at an absolute premium and data latency reduction is critical. While 10GbE can be implemented over existing IP-based Ethernet networks, InfiniBand requires the purchase, implementation, and support for an InfiniBand fabric including dedicated switches, adapters, and fabric management and services. This additional, costly requirement has proven to be beyond the reach of many potential users. 10GbE networks 10GbE employs an IP-based Ethernet network. Ethernet‟s world-wide installed base is a major advantage to those users contemplating 10GbE adoption. One of the perceived limitations of Ethernet has been that it is not reliable enough for critical data transmission. That limitation did exist prior to the introduction of Gigabit Ethernet when networks operated in half duplex mode which could cause significant data loss. While the problem of potential data loss was addressed with data buffers and carrier-sensing multiple-access with collision detection (CSMA/CD) software protocols, these measures increased transmission latency in Ethernet networks. Full duplex operation 10GbE standards support only full duplex1 operation. Full duplex is characterized by simultaneous transmission and reception channels. With the introduction of full-duplex, switched Ethernet with QoS features and adequate bandwidth provisioning, Ethernet can be very reliable. New Data Center Bridging standard2 features such as Priority based Flow Control and Congestion Notification allows Ethernet to become nearly lossless, and with reliability comparable to that of FC and InfiniBand. 1 The full duplex Gigabit standards are described on the 10gea.org site-www.10gea.org/gigabit-ethernet.htm 2 For more information go to http://www.ieee802.org/1/pages/dcbridges.html 4