The key to broad use of 10GigE: traditional RJ-45 Ethernet at 10-gigabit speed will mainstream copper connectivity

Communications News, Feb, 2008 by Kamal Dalmia

BASE-T, or twisted-pair copper cable with RJ-45 connectors, is the most cost-effective and easiest way to create Ethernet local area networks. It is the connectivity of choice for more than 90 percent of the links in data centers, and the nearly exclusive connection to the corporate desktop and notebook computers. It provides a simple plug-and-play paradigm that allows IT managers to connect any RJ-45 to any other, with the technology providing automatic connection and rate sensing that promises interoperability with the vast variety of equipment present in every IT installation.

10GBASE-T brings this time-tested use model to the 10-Gbps rate of Ethernet. The IEEE standard for 10GBASE-T prescribes full-duplex operation over the four wire pairs present in every RJ-45 jack. In addition, the standard incorporates enhancements to the traditional auto-negotiation protocol, enabling backward compatibility to the billions of RJ-45 ports already deployed in IT installations worldwide.

Continuing the ease of deployment theme, 10GBASE-T is specified to work over existing CAT 6 cable, as well as a number of other cable types. The standard requires a channel with 500 MHz of bandwidth on the cable. CAT 6 cable complying with the IEEE standard is guaranteed to support transmissions up to 55 meters.

The cable industry is providing further support for the standard and has created an augmented CAT 6 (CAT 6a) cable that has been designed to reduce cable-to-cable crosstalk (i.e., alien crosstalk) and enables links of up to 100 meters. Additionally shielded cable, or CAT 7, is called out in the standard to also extend up to 100 meters.

Several vendors are in production with silicon products that implement 10GBASE-T and have demonstrated interoperability between their implementations. This is a clear signal of the maturity of the standard and the ability to carry the written document to a practical implementation. A number of equipment vendors of switches, network interface cards and servers have recently announced they are now sampling 10GBASE-T products, and full networks were demonstrated at November's SC-07 show in Reno, Nev., using products from a number of companies.

This year, 10GBASE-T is expected to hit the data center floor. Several switch and server vendors performed field trials of their products in late 2007, with others scheduled for early 2008, gearing up for general availability of the products in coming months. Switches priced near or below $500 per port are promised, and, at these port prices, 10GBASE-T will be cheaper per gigabit than 1-GigE connections.

Early applications are likely to include high-performance computing clusters, as the increased rate of communication from I gigabit to 10 gigabit reduces the transport latency of the link to well under that of I GigE. In more mainstream data centers, 10GBASE-T will be used in applications where previously multiple 1-gigabit links needed to be deployed with "link aggregation" and can now be replaced by a single cable, providing both cost and ease-of-management benefits.

As 10GBASE-T-enabled servers come online both in rackmount and blade configurations, they will be deployed with server virtualization technology, providing a multiplier on the effectiveness of each server dollar invested. In the long run, as technologies such as Fiber Channel over Ethernet and iSCSI mature, 10GBASE-T promises to be a candidate for unifying the whole fabric of the data center on the simple Ethernet BASE-T model.

The Ethernet Alliance (www.ethernetalliance.org) is a consortium of system and component vendors, industry experts, and university and government professionals who are committed to the continued success and expansion of Ethernet technology. The mission of the Ethernet Alliance is to promote industry awareness, acceptance, and advancement of technology and products based on both existing and emerging IEEE 802 Ethernet standards and their management.

Board of Directors: Brad Booth, AMCC, president; Thomas Scheibe, Cisco, treasurer; Val Oliva, Foundry Networks, secretary; David Law, 3Com; Yong Kim, Broadcom; Steve Garrison, Force10 Networks; Rob Hays, Intel; Eric Ryu, Samsung; Dilip Modi, Sun Microsystems; Dan Dove, ProCurve.

Prior to joining Teraneties, Kamal Dalmia was director of product marketing at Marvell, where he was instrumental in the success of several gigabit, 10-gigabit and Fast Ethernet physical layer products. He holds several U.S. patents and a master's degree in electrical engineering from the University of British Colombia.

For more information: rsleads.com/802cn-260