Ethernet: The Definitive Guide, 2nd Edition

Chapter 11. 10 Gigabit Ethernet

The IEEE 10 Gb/s standard was first specified in the 802.3ae supplement, which was adopted in 2002. This supplement defined the basic 10 Gigabit system and a set of fiber optic media standards. Subsequent 10 Gb/s supplements have added copper media types, including a short-range copper connection based on twinaxial cable and a twisted-pair media system capable of reaching 300 m. This chapter describes the copper media systems first, and then the fiber optic systems.

Table 11-1 lists several of the supplements created during the development of the 10 Gb/s Ethernet standards. These supplements have since been incorporated into the main 802.3 standard as Clause 44, “Introduction to 10 Gb/s baseband network,” and Clauses 46 through 55, which describe the media systems and other elements.

Table 11-1. 10 Gigabit supplements

Supplement	Date	Identifier
802.3ae	June 2002	10 Gb/s and fiber optic media systems
802.3ak	February 2004	10GBASE-CX4 twinaxial copper media
802.3an	June 2006	10GBASE-T twisted-pair copper media
802.3aq	September 2006	10GBASE-LRM 10 Gb/s over multimode fiber

The 10 Gb/s media systems support full-duplex mode only. In the modern era of switched Ethernet ports with full-duplex media links connecting ports to devices, the normal operating mode is full duplex. The Gigabit Ethernet half-duplex mode was never adopted by vendors, and given the timing constraints, a half-duplex mode for 10 Gb/s operation made even less sense than it did for 1 Gb/s Ethernet. ...