Ethernet has evolved to the point that it can be used on a number of different cabling systems.
The earliest version of Ethernet ran on a rigid coaxial cable that was called Standard Ethernet cable, but was more commonly referred to as thicknet. While thicknet was difficult to work with (because it was not very flexible and was hard to install and connect nodes to), it was reliable and had a usable cable length of 500 meters. 10Base-5 systems can still be found in older installations, typically used as backbone cable, but virtually no reason exists for you to install a new 10Base-5 system today.>>10Base-T Ethernet
100Mbps Ethernet Systems
The 100Mbps version of 802.3 Ethernet specifies a number of different methods of cabling a Fast Ethernet system, including 100Base-TX, 100Base-T4, and 100Base-FX.
The 100Base-TX specification uses physical-media specifications developed by ANSI that were originally defined for FDDI (ANSI specification X3T9.5) and adapted for twisted-pair cabling. The 100Base-TX requires Category 5e or better cabling but uses only two of the four pairs. The eight-position modular jack (RJ-45) uses the same pin numbers as 10Base-T Ethernet.
>>The 100Base-T4 specification was developed as part of the 100Base-T specification so that existing Category 3–compliant systems could also support Fast Ethernet. The designers accomplish 100Mbps throughput on Category 3 cabling by using all four pairs of wire; 100Base-T4 requires
a minimu.m of Category 3 cable. The requirement can ease the migration path to 100Mbps technology.
Gigabit Ethernet (1000Mbps)
1000Mbps Ethernet was supported only on fiber-optic cable. The IEEE 802.3z specification included support for three physical-media options (PHYs), each designed to support different distances and types of communications:
Targeted to intra-building backbones and horizontal cabling applications such as to workstations and other network nodes, 1000Base-SX is designed to work with multimode fiber-optic cable at the 850nm wavelength.
Designed to support backbone-type cabling such as inter-building campus backbones, 1000Base-LX is for Single-mode Fiber-optic Cable at 1310nm, though multimode fiber can be used for short inter-building backbones and intra-building cabling applications.
Designed to support interconnection of equipment clusters, this specification uses 150 ohm STP cabling similar to IBM Type 1 cabling over distances no greater than 25 meters. When cabling for Gigabit Ethernet using fiber, you should follow the ANSI/TIA-568-C standards for 62.5/125 micron or 50/125 micron multimode fiber for horizontal cabling and 8.3/125 micron single-mode fiber for backbone cabling. See Table 6 of Annex D in ANSI/TIA-568-C.0.
The IEEE approved the first Gigabit Ethernet specification in June, 2002: IEEE 802.3ae. It defines a version of Ethernet with a nominal data rate of 10 Gbit/s. Over the years the following 802.3 standards relating to 10GbE have been published: 802.3ae-2002 (fiber -SR, -LR, -ER, and -LX4 physical-media-dependent devices[PMDs]), 802.3ak-2004 (-CX4 copper twin-ax InfiniBand type cable), 802.3an-2006 (10GBASE-T copper twisted pair), 802.3ap-2007 (copper backplane -KR and-KX4 PMDs), and 802.3aq-2006 (-LRM over legacy multimode fiber -LRM PMD with electronic dispersion compensation [EDC]). The 802.3ae-2002 and 802.3ak-2004 amendments were consolidated into the IEEE 802.3-2005 standard. IEEE 802.3-2005 and the other amendments have been consolidated into IEEE Standard 802.3-2008. In the premises environment, 10 Gigabit Ethernet is mostly used in data center storage servers,high-performance servers, and in some cases for intra-building backbones. It can be used for connection directly to the desktop.
10GBASE-SR (short range) uses 850nm VCSEL lasers over multimode fibers. Low-bandwidth 62.5/125 micron (OM1) and 50/125 micron (OM2) multimode fiber support limited distances of 33–82 meters. To support 300 meters, the fiber-optics industry developed a higher bandwidth version of 50/125 micron fiber optimized for use at 850nm.
10GBASE-LR (long range) uses 1310nm lasers to transmit over single-mode fiber up to 10 kilometers. Fabry-Pérot lasers are commonly used in 10GBASE-LR optical modules. Fabry-Pérot lasers are more expensive than 850nm VCSELs because they require the precision and tolerances to focus on very small single-mode core diameters (8.3 microns). 10GBASE-LR ports are typically used for long-distance communications.
10GBASE-T supports 10Gbps over Category 6A UTP or Category 7 shielded (per ISO/IEC 11801Ed. 2) twisted-pair cables over distances of 100 meters. Category 5e is supported to much lower distances due to its limited bandwidth. Special care needs to be taken in installing Category 6A cables in order to minimize alien cross-talk on signal performance.
The IEEE 802.3ba committee is standardizing 40 and 100 Gigabit Ethernet. This will be deployed over OM3 50/125 multimode optical fiber for 100–200 meters, and research is progressing to make it available over UTP for distances up to 10 meters.This could be the speed point at which there is mass conversion of copper to fiber-based systems.
References: FIBERSTORE PRODUCTS INFO