In computer networking, Fast Ethernet is a collective term for a number of Ethernet standards that carry traffic at the nominal rate of 100 Mbit/s (the original Ethernet speed was 10 Mbit/s). Fast Ethernet is sometimes referred to as 100BASE-X, where “X” is a placeholder for the FX and TX variants. The standard specifies the use of CSMA/CD for media access control. A full-duplex mode is also specified and in practice all modern networks use Ethernet switches and operate in full-duplex mode.
The “100” in the media type designation refers to the transmission speed of 100 Mbit/s, while the “BASE” refers to baseband signalling. The letter following the dash (“T” or “F”) refers to the physical medium that carries the signal (twisted pair or fiber, respectively), while the last character (“X”) refers to the used encoding method.
Small Formfactor Pluggable (SFP)
The small form-factor pluggable (SFP) is a compact, hot-pluggable transceiver used for both telecommunication and data communications applications. The form factor and electrical interface are specified by a multi-source agreement (MSA) under the auspices of the SFF Committee. It is a popular industry format jointly developed and supported by many network component vendors. The SFP interfaces a network device (a switch, router, media converter or similar device) to a fiber optic or copper networking cable.
100BASE-TX SFP Transceiver
100BASE-TX is the predominant form of Fast Ethernet, and runs over two wire-pairs inside a category 5 or above cable. Like 10BASE-T, the active pairs in a standard connection are terminated on pins 1, 2, 3 and 6. Since a typical category 5 twisted pair cable contains 4 pairs, it can support two 100BASE-TX links with a wiring adaptor. Each network segment can have a maximum cabling distance of 100 metres (328 ft). In its typical configuration, 100BASE-TX uses one pair of twisted wires in each direction, providing 100 Mbit/s of throughput in each direction (full-duplex). BlueOptics© SFP 1000BASE-T, 100M, Copper Transceiver is one option for this category with RJ45 connector from CBO is designed for Gigabit Ethernet (GbE) high-speed applications of up to 1.25 gigabits per second over Cat5 Twisted Pair Cable.
100BASE-FX is a version of Fast Ethernet over optical fiber. This application uses a 1310nm near-infrared (NIR) light wavelength transmitted via two strands of optical fiber, one for receive (RX) and the other for transmit (TX). Maximum length is 412 metres. The BlueOptics© BO05A13602 SFP transceiver with LC duplex connector from CBO is designed for short-range multi-mode Fast Ethernet (FE), Fibre Channel over Ethernet (FCoE) or OC-3/STM1 SDH/SONET applications of up to 155 megabits per second.