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Overview of the Gigabit Ethernet standard

This lesson from our network cabling series reviews the Gigabit Ethernet standard, also known as 1000BASE, as well as variations of 10BASE Ethernet.

The Gigabit Ethernet standard, also referred to as 1000BASE, GbE or 1 GigE, is defined by the IEEE 802.3-2008 standard and provides 10 times faster transfer speeds than 100BASE Ethernet. Gigabit Ethernet is today's industry Ethernet standard for workstations, access points and access-level switches.

Gigabit Ethernet's most popular standards are 1000BASE-T twisted copper cable and 1000BASEX (fiber optic).


The 1000BASE-T is the IEEE 802.3ab Gigabit Ethernet standard for GbE over copper wiring. Similar to 100BASE-T, 1000BASE-T can run up to a maximum of 100 meters or 330 feet and is supported on CAT5e, CAT6 and CAT7 cabling.

With 1000BASE-T, all four pairs of the copper cable are used; however, only two pairs are used for the negotiation of the link. If the cable only has two pairs available, the negotiation between the two devices might succeed, but the link will not come up.

Crossover cables are not required for 1000BASE-T links as the two endpoints will automatically negotiate and bring up the link even when connected by a straight-through cable.


The 1000BASE-X is the industry Gigabit Ethernet standard for GbE over fiber optic. There are four Gigabit Ethernet over fiber optic standards of which the most popular are the 1000BASE-SX and 1000BASE-LX standards.

The 1000BASE-SX standard is for operation over multimode fiber using 770- to 860-nanometer light wavelength. Multimode Gigabit Ethernet fiber can run up to 200 meters when using 62.5/125 fiber or 550 meters when using 50/125 fiber. Multimode Gigabit Ethernet is usually used for backbone connections between switches located in a data center, short-distant buildings or different levels within a building.

The 1000BASE-LX standard is for operation over single-mode fiber using 1,270- to 1,355-nanometer light wavelength. Single-mode Gigabit Ethernet fiber can run up to 5 kilometers depending on the fiber type and is commonly used for backbone connections between buildings and long-distant endpoint connections.


The 10 Gigabit Ethernet standard has become popular in the past couple of years, even though the IEEE standard (802.3ae) has been in development since 2002. The key advantages of 10 Gigabit Ethernet are that it provides speeds 10 times faster than Gigabit Ethernet and is supported over copper and fiber optic. Rarely used for endpoint connectivity (workstations or laptops), 10 Gigabit Ethernet is found mainly in data centers connecting servers, switches and storage devices. In some cases, it is also used for backbone links between buildings and switches.


10GBASE-T is the Ethernet standard covering copper wiring, standardized in 2006 via the IEEE 802.3an standard and is supported only by CAT6 and CAT7 twisted pair cables. When using CAT6 cables, 10 Gbps throughput is only supported for up to 55 meters, whereas CAT7 cabling can support 10 Gbps for up to 100 meters.

A variety of standards define 10 Gigabit Ethernet over fiber, among them 10GBASE-SR, 10GBASE-LR, 10GBASE-ER and 10GBASE-LX4/LRM. Following is a brief overview of these Gigabit Ethernet standards:

  • 10GBASE-SR: Known as short reach (SR), used for short-distance connections via multimode fiber optic using the 850-nanometer wavelength. Maximum distance is 400 meters, depending on the type of fiber optic cable.
  • 10GBASE-LR: Known as long reach (LR), used for long-distance connections up to 10 kilometers via single-mode fiber optic cable using the 1310-nanometer wavelength.
  • 10GBASE-ER: Known as extended reach (ER), used for extra-long-distance connections up to 40 kilometers via single-mode fiber optic cable using the 1550-nanometer wavelength.
  • 10GBASE-LX4/LRM: The LX4 standard was replaced by the LRM (long-reach multimode). LX4 operates at distances up to 300 meters for multimode fiber or 10 kilometers for single-mode fiber and uses the 1310-nanometer wavelength. The LRM standard only uses multimode fiber and can cover distances of up to 220 meters, again using the 1310-nanometer wavelength.

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This was last published in June 2016

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