10 Gbit/sec Ethernet over copper

The IEEE has put its stamp of approval on a new standard that defines how copper cable can be used with Ethernet systems running at 10 Gbit/sec.

The IEEE has approved a standard that defines how copper cable can be used with Ethernet systems running at 10 Gbit/sec. Before approval of the standard, 1 Gbit/sec was the fastest available Ethernet rate over copper cabling.

The new standard, IEEE 802.3ak-2004, provides an economical way for Ethernet switches and server clusters located within 15 m of each other in equipment rooms and data centres to be interconnected at 10 Gb/sec. The new standard complements the standards for 10 Gbit/sec Ethernet fibre optic cable interfaces approved in 2002.

IEEE 802.3ak, ‘Physical Layer and Management Parameters for 10 Gbit/sec Operation, Type 10GBASE-CX4,’ is based on the 10 Gigabit Attachment Unit Interface (XAUI) chip-to-chip interface and specifies signals for transmission over balanced, shielded-copper cabling.

Connections for 10 Gigabit Ethernet that require runs of more than 15 m will be served by 10 Gbit/sec fibre optic cable under the IEEE 802.3ae standard.

‘The availability of 10GBASE-CX4 copper-based interface should accelerate the deployment of 10 Gbit/sec Ethernet,’ said Bob Grow, Chair of the 802.3 Working Group and a Principal Architect at Intel. ’10GBASE-CX4 will be an easy addition to 10 Gigabit Ethernet systems because of its similarity to the XAUI interface.’

According to Dan Dove, Chair of the 802.3ak Task Force and Principal Engineer, HP ProCurve Networking Business, the standard seeks to make 10 Gbit/sec performance more economical. ‘Cost effectiveness is critical for technology adoption,’ he said. ‘We reused portions of IEEE 802.3 and other standards to simplify and lower the cost of implementation.

‘For instance, 10GBASE-CX4 specifies the same type of connectors and cables now used with 4X InfiniBand,’ said Dove. ‘It will allow implementers to incorporate 10GBASE-CX4 capability directly within highly integrated chips. It also minimises design, installation and maintenance costs by preserving IEEE 802.3 network architecture, management and software features. As a result, we expect installation costs for copper 10GBASE-CX4 interconnections to be one-tenth that of comparable 10GBASE-optical solutions.’