Ethernet physical layerThe physical-layer specifications of the Ethernet family of computer network standards are published by the Institute of Electrical and Electronics Engineers (IEEE), which defines the electrical or optical properties and the transfer speed of the physical connection between a device and the network or between network devices. It is complemented by the MAC layer and the logical link layer. The Ethernet physical layer has evolved over its existence starting in 1980 and encompasses multiple physical media interfaces and several orders of magnitude of speed from 1 Mbit/s to 400 Gbit/s.
Gigabit EthernetIn computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use in 1999, and has replaced Fast Ethernet in wired local networks due to its considerable speed improvement over Fast Ethernet, as well as its use of cables and equipment that are widely available, economical, and similar to previous standards.
Optical fiberAn optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables.
Fast EthernetIn computer networking, Fast Ethernet physical layers carry traffic at the nominal rate of 100 Mbit/s. The prior Ethernet speed was 10 Mbit/s. Of the Fast Ethernet physical layers, 100BASE-TX is by far the most common. Fast Ethernet was introduced in 1995 as the IEEE 802.3u standard and remained the fastest version of Ethernet for three years before the introduction of Gigabit Ethernet. The acronym GE/FE is sometimes used for devices supporting both standards.
Wavelength-division multiplexingIn fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e., colors) of laser light. This technique enables bidirectional communications over a single strand of fiber, also called wavelength-division duplexing, as well as multiplication of capacity. The term WDM is commonly applied to an optical carrier, which is typically described by its wavelength, whereas frequency-division multiplexing typically applies to a radio carrier which is more often described by frequency.
Optical networkingOptical networking is a means of communication that uses signals encoded in light to transmit information in various types of telecommunications networks. These include limited range local-area networks (LAN) or wide-area networks (WAN), which cross metropolitan and regional areas as well as long-distance national, international and transoceanic networks. It is a form of optical communication that relies on optical amplifiers, lasers or LEDs and wave division multiplexing (WDM) to transmit large quantities of data, generally across fiber-optic cables.
Leaky bucketThe leaky bucket is an algorithm based on an analogy of how a bucket with a constant leak will overflow if either the average rate at which water is poured in exceeds the rate at which the bucket leaks or if more water than the capacity of the bucket is poured in all at once. It can be used to determine whether some sequence of discrete events conforms to defined limits on their average and peak rates or frequencies, e.g. to limit the actions associated with these events to these rates or delay them until they do conform to the rates.
Token bucketThe token bucket is an algorithm used in packet-switched and telecommunications networks. It can be used to check that data transmissions, in the form of packets, conform to defined limits on bandwidth and burstiness (a measure of the unevenness or variations in the traffic flow). It can also be used as a scheduling algorithm to determine the timing of transmissions that will comply with the limits set for the bandwidth and burstiness: see network scheduler.
Performance indicatorA performance indicator or key performance indicator (KPI) is a type of performance measurement. KPIs evaluate the success of an organization or of a particular activity (such as projects, programs, products and other initiatives) in which it engages. KPIs provide a focus for strategic and operational improvement, create an analytical basis for decision making and help focus attention on what matters most. Often success is simply the repeated, periodic achievement of some levels of operational goal (e.g.
Business performance managementBusiness performance management (BPM), also known as corporate performance management (CPM) enterprise performance management (EPM), organizational performance management, or simply performance management are a set of management and analytic processes that ensure activities and outputs meet an organization's goals in an effective and efficient manner. Business performance management is contained within approaches to business process management.
