Chapter 5

Ethernet Standards

Standards for copper cable:

-10Base-T - uses a twisted pair cable with maximum lengths of 100 meters. The cable is thinner and more flexible than the coaxial cable used for the 10Base-2 or 10Base-5 standards.

-100Base-T (Fast Ethernet) - based on the older Ethernet standard. Because it is 10 times faster than Ethernet, it is often referred to as Fast Ethernet.

-1000Base-T - standard that defines 1 Gb/s data transfer over distances of up to 100 meters using four pairs of CAT-5 balanced copper cabling and a 5-level coding scheme.

-10GBase-T - standard for transmitting 10 Gbps over twisted pair, 10GBase-T. This standard was a breakthrough in pushing the limits of the twisted pair medium. To achieve such dramatic data transmission rates, however, 10GBase-T segments require Cat 6 or Cat 7 cabling. Still, as with other twisted pair Ethernet standards, the maximum segment length for 10GBase-T is 100 meters.

Standards for fiber-optic cable:

-100Base-FX - standard that specifies a network capable of 100-Mbps throughput
that uses baseband transmission and fiber-optic cabling. 100Base-FX requires multimode
fiber containing at least two strands of fiber.

-1000Base-LX - The 1000 in 1000Base-LX stands for 1000-Mbps—or 1-Gbps—throughput. Base stands for baseband transmission, and LX represents its reliance on long wavelengths of 1300 nanometers. (A nanometer equals 0.000000001 meters, or about the width of six carbon
atoms in a row.) 1000Base-LX has a longer reach than any other 1-gigabit technology
available today.

-1000Base-SX - similar to 1000Base-LX in that it has a maximum throughput
of 1 Gbps. However, it relies on only multimode fiber-optic cable as its medium. This
makes it less expensive to install than 1000Base-LX. Another difference is that 1000Base-SX
uses short wavelengths of 850 nanometers—thus, the SX, which stands for short. The maximum segment length for 1000Base-SX depends on two things: the diameter of the fiber and the modal bandwidth used to transmit signals.

Standards for 10-gigabit fiber-optic:

-10GBase-SR and 10GBase-SW 

-10GBase-LR and 10GBase-LW 

-10GBase-LR and 10GBase-LW