Ethernet meets data center needs: the demand for faster server connections drives 40-Gigabit and 100-Gigabit Ethernet efforts.

A historical shift is on the horizon as Ethernet breaks free from the tradition of exclusive 10-time speed increases with IEEE's move to standardize 40-Gigabit and 100-Gigabit Ethernet to support major changes under way in enterprise computing and network architectures. The rise of mega data centers, networked storage, computer clustering and virtualization present sophisticated IT challenges, requiring new skills and technologies to address them. While businesses are deploying networking solutions to address these challenges, engineers from the world's leading technology companies are busy defining future Ethernet standards to handle the networking demands of the next decade.

New IEEE 802.1 standards for congestion management are being defined to improve endto-end storage networking over Ethernet. These new capabilities will enable Ethernet to service multiple traffic classes with different performance requirements, such as LAN and iSCSI traffic, over the same network-promising to deliver the longanticipated benefits of I/O convergence.

The T11 technical committee for storage is developing a specification for Fibre Channel over Ethernet (FCoE) that will enable servers to access Fibre Channel storage-area networks (SANs) through an Ethernet network--cost-ef- fectively extending the reach of existing SANs in the enterprise. These standards, along with supporting products, will make networked storage over 10-GigE a cost-effective and compelling solution for businesses of all sizes. Meanwhile, the IEEE 802.3 Ethernet working group is looking beyond 10-GigE by defining standards for 40- and 100-Gigabit Ethernet, which are expected to be ratified by 2010.

Demand for faster server connections is being driven by multicore processing, virtualization and networked storage. Today, most IT managers are satisfying the bandwidth demand by adding multiple GigE network interface cards (NICs) into each server. The resulting spaghetti of GigE network cables is beginning to make 10-GigE an attractive option on servers as 10-GigE-capable blade servers and lower-cost 10GBASE-T NICs and switches become available.

40-GigE is eyed as the next-generation server connection speed after 10-GigE. Rather than spacing 10x bandwidth increases apart by a decade or so, server vendors want to provide a gradual upgrade path from 10 gigabit to 40 gigabit, with 100 gigabit following. This progression more closely tracks the I/O bandwidth requirements for computers, which according to Moore's Law doubles approximately every two years.

40-GigE will provide faster throughput than 10-GigE at lower cost and power than 100-GigE. 40 gigabit was selected, instead of 25 or 50 gigabit, for example, because it will run over existing four-lane, 10-Gbps-capable backplanes and will complement planned PCI-Express bandwidth improvements. Deployment of 40-GbE is expected to begin in blade servers, similar to 10-GigE, due to the lower cost of running high-speed signals over a backplane versus externally cabled solutions.

100-Gigabit Ethernet, which is being defined alongside 40-GigE, will provide the necessary bandwidth aggregation for the growing numbers of 10-GigE and future 40-GigE connections in the data center. 100-GigE is also needed to handle the exponential increase in communications across metro and wide area networks resulting from growing Internet usage, voice and video over IP, and collaboration among dispersed work groups. 100-GigE will be defined to work over a variety of short- and long-reach optical and copper cables, addressing the broad range of application requirements for the network core.

This is not the first time Ethernet has changed to meet future networking needs. In fact, Ethernet has continuously evolved over the past 25 years from a shared local area bus to high-speed, switched networks that can communicate over long distances.

Ethernet's propensity to evolve to meet the changing needs of enterprises is one reason it is the number one networking technology worldwide, with Ethernet connections being a standard feature on nearly every PC and server today. Future 40-Gigabit and 100-Gigabit technologies aim to keep Ethernet's place in the enterprise network secure and growing.

Robert Hays is a director of the Ethernet Alliance and strategic planner at Intel Corp. for desktop, mobile and server networking products. For more information, read the white paper "Overview of Requirements and Applications for 40-Gigabit and 100-Gigabit Ethernet" at www.ethernetalliance. org/technology.

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