The IEEE 802.3ae standard was adapted to include 10 Gbps, full-duplex transmission over fiber-optic cable. The 802.3ae standard and the 802.3 standards for the original Ethernet are very similar. 10-Gigabit Ethernet (10GbE) is evolving for use not only in LANs, but also for use in WANs and MANs.
Because the frame format and other Ethernet Layer 2 specifications are compatible with previous standards, 10GbE can provide increased bandwidth to individual networks that is interoperable with the existing network infrastructure.
10Gbps can be compared to other varieties of Ethernet in these ways:
• Frame format is the same, allowing interoperability between all varieties of legacy, fast, gigabit, and 10 gigabit Ethernet, with no reframing or protocol conversions necessary.
• Bit time is now 0.1 ns. All other time variables scale accordingly.
• Because only full-duplex fiber connections are used, there is no media contention and CSMA/CD is not necessary.
• The IEEE 802.3 sublayers within OSI Layers 1 and 2 are mostly preserved, with a few additions to accommodate 40 km fiber links and interoperability with other fiber technologies.
With 10Gbps Ethernet, flexible, efficient, reliable, relatively low cost end-to-end Ethernet networks become possible.
Future Ethernet Speeds
Although 1-Gigabit Ethernet is now widely available and 10-Gigabit products are becoming more available, the IEEE and the 10-Gigabit Ethernet Alliance are working on 40-, 100-, or even 160-Gbps standards. The technologies that are adopted will depend on a number of factors, including the rate of maturation of the technologies and standards, the rate of adoption in the market, and the cost of emerging products.
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