Geek Gab-Gigaplane


Geek Gab

"Variety" is a weekly magazine that covers the Hollywood entertainment business. It coined the word "geek gab," which it refers to as the proliferation of Web sites claiming to put forward the latest hot news on films , studios and networks. The "news," however, is often unsubstantiated rumor, can be vicious and can destroy a film.

Geek Testosterone

When Microsoft turned over internal company materials to the court in Washington that was hearing its anti-trust case, several people believed that they revealed a company running on "geek testosterone." A geek is a computer enthusiast who doesn't have a life beyond computers. Testosterone is the sex hormone, C19H28O2, secreted by the testes, that stimulates the development of male sex organs, secondary sexual traits, and sperm.

Geekosphere

A definition courtesy Wired Magazine: The area surrounding one's computer where trinkets, personal mementos, toys and "monitor pets" are displayed. A place where computer geeks show their colors.

Geekspeak

Geekspeak is the language geeks speak. A geek is a computer enthusiast who doesn't have a life beyond computers and the Internet.

Geezer Glut

The large number of seniors that will result as the baby boom generation ages.

Gender

Connectors, plugs and receptacles are assigned a gender to describe their physical type. Ones with pins are male, and those with holes into which the male pins slide are female . See Gender Bender.

Gender Bender

A device which changes the gender of a connector, plug or receptacle. A gender bender is typically a small plug with all male pins on one side and all male pins on the other. By plugging a female connector into one side of a gender bender, you've effectively changed the female gender of the cable to male. Alternatively, a gender bender could be female on either side. But a gender bender must be the same on both sides.

Gender Changer

Another name for a gender bender. See Gender Bender.

Genderless Connector

Also called data connector or hermaphroditic connector. Invented by IBM. The connector doesn't require male and female plugs to make a connection. It was designed for token-ring applications. It was too big and clunky for my taste.

Gene Doping

Tweaking an athlete's genes to produce more hormones or other performance- boosting substances.

General Availability

How a product gets to market varies from one company to another. But typically, along the way, there's something called an alpha ” the first version of hardware or software. It typically has so many bugs you only let your employees play with it. A beta is the next version. It's a pre-release version and selected customers (and the press) become your guinea pigs. They give you feedback. After beta, and when the bugs are removed and the features have been fine-honed, comes "general availability." That's when the product is finally available for buying by the general public.

General Call

The letters CQ in the international code and used as a general inquiry call.

General Claims

A Verizon definition: Claims that cover more than one working telephone number.

General Packet Radio Service

GPRS. General Packet Radio Service is the data service enhancement for GSM, the European standard digital cellular service. GPRS, a packet-switched service which will support the X.25 and TCP/IP packet protocols, is widely expected to be the next major step forward in the evolution of GSM technology. GPRS, an important component in the GSM evolution entitled GSM+, enables high-speed mobile datacom usage. It is most useful for " bursty " data applications such as mobile Internet browsing, e-mail and push technologies. These applications easily can be supported at speeds of 56 Kbps. GPRS has been demonstrated as fast as 115 Kbps, which also makes it suitable for high-speed file transfers. Notably, GPRS will support simultaneous voice and data communications over the same wireless link; voice, of course, always takes precedence. GPRS-compatible terminal equipment will include cell phones with microbrowsers and displays supporting WAP (Wireless Application Protocol), smart phones with full-screen display capability, and mobile credit card readers. Laptops can be equipped with GPRS modems, or can connect to a GPRS-capable cell phone. See also HSCSD.

General Premises Cabling Licence

In Australia, a previous cabling license that was replaced on July, 1, 1996, by the Base General Premises Cabling Licence (BCL). See BCL.

General Protection Fault

GPF. A General Protection Fault is an indication that Windows 3.xx has tried to assign two or more programs to the same area in memory. Obviously that's not possible, since two things can't occupy the same area in memory. As a result, your screen stops and says "General Protection Fault." If you can save what you're doing, do it. If you have other programs open , try and save the material in them. Close Windows and then do a cold reboot. Do not continue to work after you have received a General Protection Fault. You must reboot. Better do a cold reboot, too.

General Purpose Network

An AT&T term for a network suitable for carrying many forms of communication ” voice and data, circuit and packet, image, sensor or signaling, for example.

General Release

When software is finally finished and ready to be sold to the general public, it said to be in "General Release." Before it is in general release, it is still in beta. Beta software is not alleged to be bug-free. General release software is meant to be bug-free. Sometimes it is.

General Telemetry Processor

GTP. A device that receives and processes telecommunications equipment alarming protocols such as TBOS (Telemetry Bit-Oriented Serial).

General Trunk Forecast

A telephone company term. GTF. A forecast of future trunk circuit requirements. This forecast covers the current year and the future four years .

Generation D

Generation Digital refers all the people who have grown up with computers and digital technology. There are people now who have never known a world without PCs, MP3 players, touchtone phones, CDs and DVDs. My children look askance at me when I ask what the name of the record playing on the radio? I am definitely not a member of Generation D.

Generational Loss

The reduction in picture quality resulting in the copying of analog images for editing and distribution.

Generations, Computer

As computers have improved, so the industry's pundits have assigned "generations" to those improvements. The concept of generations is not perfect nor finite. Here's our best shot on generations in computers:

  • First generation: 1951-1958, core memory 8 Kbytes to 32 Kbytes.

  • Second generation: 1958-1964, transistor technology, memory 32 Kbytes to 64 Kbytes.

  • Third generation: 1964-1975, integrated circuitry .

  • Fourth generation: 1975-date, non procedural languages, software driven.

  • Fifth generation: into the 1990s, natural language programming, parallel processing and super computing.

  • Sixth generation: in the 2000, will process knowledge rather than data.

Generations, PBX

As PBXs have improved, so the industry's pundits have assigned "generations" to those improvements, as they did in computers. The concept of generations is not perfect nor finite. Here's our best shot on generations in PBXs:

First generation: 1920s to the late 1960s. Step-by-step mechanical equipment. The first and the last of the step-by-step Bell PBXs switches was called a 701. Lee Goeller says the 701 "was the best PBX ever built. It was infinitely flexible. It was just too BIG. In fact, it was usually bigger than the office it served . This era of the stepper will be remembered as the era the Bell System was intact and had the gaul to rent operator chairs."

Second Generation: Late 1960s: Bell 801 reed relay switch. Stromberg Carlson 800 series reed relay switch. GTE had a series, also. Reed relay switches were not very popular.

Third Generation: 1974 and 1975: Rolm introduces its first CBX, an electronic, solid- state PBX. AT&T introduces Dimension. Digital Telephone Systems introduced the D1200. Northern introduced its first stored-program controlled SL-1. Some of these PBXs switched voice digitally, though they used different techniques, including PCM, PAM, and Delta Modulation. The codecs were in the switch, not in the instruments.

Fourth generation: early 1980s. Distributed processing. Northern, Rolm and NEC and others introduced remote modules ” slaves to the master switch at headquarters. These switches also added the capability of handling data without using modems. Switches like Lexar and InteCom were designed from the beginning to handle data without modems, thus requiring digital capability out to the set.

Fifth generation: CXC, Anderson Jacobson and Ztel and others called themselves "fourth generation." When they started to fail, some people called them the "fifth generation." It wasn't clear exactly what that generation was. But they all got lots of publicity and the PBXs from CXC, Anderson Jacobson and Ztel ultimately failed.

Sixth generation: Networked PBXs. Sit in New York. Operate your national network as if it were in the same building. Bingo, you can transfer calls across the country. All your messaging is the same wherever you sit on the network. Lee Goeller, however, says you can network stepper PBXs. In fact, in 1971 he says he managed one of the biggest integrated voice and data networks in the US using step-by-step electromechanical PBXs (701s made by AT&T). It was the world's largest dial tandem network. He had 63 different locations and three hubs. Seventh generation: Open Architecture. You can now program your own PBX. For more, see the NORSTAR Command Set.

Eighth generation: Dumb switches. You can now buy completely dumb phone systems which are just basically switches. To get them to do anything they require an external computer (and software programming that computer) to drive the dumb switch. Often the "driving" is done through one or more serial ports.

Ninth generation: PC-based switches. Picture a PC server running Windows NT or 2000. The server contains some telephony boards that interface with the telephone network and switch calls around. The server also contains a NIC card (Network Interface Card) board which allows the server to connect to the corporate LAN and thus to the Internet. This PC- based switch thus does standard telephony things ” take calls, switch them, conference them, etc. But because it's a PC, it adds "intelligence" so it can read emails and recognize simple speech ("Call my mother"). Because it's networked and joined to the Internet, it can also let you pick up voice mail messages over the Internet ”- from anywhere in the world, for free.

In reality, the concept of generations amongst PBXs is very flimsy. But it's the stuff dictionaries are made of.

Generator

A machine which converts mechanical energy, such as the power from a piston engine into electrical energy.

Generic Access Profile

A wireless term defining signaling standards between a base station and a DECT wireless phone. There is no assumption in the DECT set of standards that handsets from one maker will work with base stations from another. GAP compliant handsets will work with GAP compliant base stations . Each manufacturer has added features to their DECT equipment which are outside the GAP specification, so a "foreign" handset may still not perform as well as the base station manufacturer's own. DECT stands for Digital European Cordless Telecommunication. The pan-European wireless standard based on time division multiple access used for limited-range wireless services. Based on advanced TDMA technology, and used primarily for wireless PBX systems, telepoint and residential cordless telephony today, uses for DECT include paging and cordless LANs. DECT frequency is 1800-1900 MHz.

Generic Attribute Registration Protocol

See GARP.

Generic Cell Rate Algorithm

An ATM function that is carried out at the user - to-network interface (UNI) level. It guarantees that traffic matches the negotiated connection that has been established between the user and the network.

Generic Flow Control Field

GFC. A 4-bit value in an ATM header for purposes of flow control between the user equipment and the carrier ATM Edge Switch across the User Network Interface (UNI). The GFC field tells the target end-station that the switch may implement some form of congestion control.

Generic Framing Procedure

See GFP.

Generic Program

A set of instructions for an ESS central office or electronic PBX that is the same for all installations of that particular equipment. Detailed differences for each individual installation are listed in a separate parameter table. Here's a more formal definition, from Telcordia. A generic program is a set of instructions for an electronic switching system or operations system that is the same for all central offices using that exact type of system. Detailed differences for each individual office are usually listed in a separated parameter table.

Generic Requirements

GR. See GR.

Generic Services Framework

GSF. Generic Services Framework is a set of software designs being implemented by Bell Northern Research (a subsidiary of Northern Telecom) to accelerate the development and testing of new features and provide a platform for the later stages of DMS SuperNode interworking with Advanced Intelligent Networking (AIN). GSF applies the principles of object-oriented programming to DMS SuperNode software, and delivers enhancements that simplify feature development and reduce testing needs. The GSF has three distinct elements:

  1. Call Separation - The new architecture uses separate software data and processes to handle the two " halves " of a call (originating and terminating).

  2. GSF Agent Interworking Protocol (AIP) - The AIP uses a standardized set of instructions to allows the two call halves to communicate.

  3. Event-Driven Call Processing (EDCP) - Just as the AIP mediates communications between call halves, EDCP handles communications within each call half. EDCP also uses a standardized set of instructions to simplify messaging.

Generic Top Level Domain

see gTLD and Domain.

Generica

Features of the American landscape that are exactly the same no matter where one is, such as fast food joints, strip malls, subdivisions.

Genlock

Circuitry that synchronizes video signals for mixing. The video circuitry determines the exact moment at which a video frame begins. Genlock allows multiple devices (video recorders cameras , etc.,) to be used together with precise timing so that they capture a scene in unison . A genlock display adapter converts screen output into an NTSC video signal, which it synchronizes with an external video source.

GEO

Geosynchronous Earth Orbit . A term for a satellite which is placed in a geosynchronous, or geostationary, orbital slot. Such orbits are always equatorial ; the satellites are placed at altitudes of approximately 22,300 miles (or 35,888 kilometers). As a result, they are synchronized with the rotation of the earth, maintaining their relative position to the earth's surface. In other words, they always appear to be in the same spot. See also Geostationary Satellite. Contrast with LEO and MEO.

Geographic Information Systems

GIS. Computer applications involving the storage and manipulation of electronic maps and related data. Applications include resource planning, commercial development, military mapping, etc. Imagine a satellite capable of photographing the distance from London to Paris with the ability to identify objects within the width of a car headlight. Or, imagine the Los Angeles Police Department possessing a "gang tracking" program that can be used to record and predict gang movements throughout the city. Welcome to the changing technological world of cartography. Researchers at the University of Missouri-Columbia believe this new form of computer-based cartography, Geographic Information Systems, can create maps that are adaptable, open- ended and smart. These maps will be able to make decisions, predict the future and effectively persuade an audience. "In today's world of new borders and increased technology, the era of the Rand McNally road map is gradually becoming superseded by an era of hitech mapping," said Karen Piper, assistant English professor at MU. "GIS can track and map movement ” from wildfires to gangs to migrating animals ” in a way paper maps could not."

Geographic Interface

First there was the ASCII interface - a screen containing nothing but ASCII letters. You saw them on airline reservation terminals. Just plain boring green type against a dark, unlit, black background. Then you got the GUI - the Graphical User Interface. Windows is the most famous GUI. It used icons to represent actions. An eraser to indicate you could remove something. A calendar to indicate that you could enter your day's schedules, etc. Now there is the "Geographic Interface." It attempts to depict objects from the real world ” or at least some circumscribed part of it, like your office. The first of these products was Magic Cap from General Magic. Another was the opening screen for Apple's eWorld on-line service. Another is Novell's Corsair technology. Click on a filing cabinet to get to its database contents. Click on a bloodhound find something. One idea behind these geographic interfaces is that there should be a libraries of objects. A set useful for an auto mechanic . Another set useful for a bond trader . The idea is that everyone gets to choose the bits and pieces of the geographic interface that he or she is most comfortable with. Some of these new geographic interfaces are endearing. Some are tiresome. We'll see if they endure.

Geographic North

North based upon some geographic grid system which may or may not correspond to "true north."

Geographical Portability

The ability to take your New York phone number to Boston, including the area code. In short, geographical portability is the ability to take all your phone number (i.e. all its 10-digits) with you wherever you go ” anywhere in North America. No timetable has been set for geographical portability in North America. See LNP (Local Number Portability) and 800 Service.

Geographical Redundancy

A level of redundancy that involves more than one system's serving a given geographical area. Geographical redundancy is a step above physical redundancy. Physical redundancy involves a backup system (e.g., router) in the same physical location as the primary system. In the event of a failure in the primary system, the backup system automatically activates. Geographical redundancy provides an additional measure of protection through another system, or set of primary and backup systems, in another physical location. While each set of systems has primary responsibility for a given geographical area, each can assume responsibility for others in the event of a catastrophic failure affecting a given physical location. The term most commonly applies to Internet access.

Geolocation Technology

Also known as Position Determination Technology (PDT). A technology used to determine the geographic coordinates of a radio-equipped mobile device, e.g., a cellular handset. See Position Determination Technology.

Geometric Dilution of Precision

GDOP or DOP (Dilution of Precision). In systems employing position determination technology such as Enhanced 911, GDOP refers to the phenomenon that causes the calculated position's accuracy to be a factor of the relative geometry of the involved units. For example, in an angle of arrival system, two fixed units measure the angle to a mobile unit. The resulting lines intersect in a point defining the mobile's position. If each measured angle has some uncertainty, the intersection is no longer a point, but say, a quadrilateral. In this case, the mobile is known only to be within the area of the quadrilateral. Depending on where the mobile is in relation to the fixed measurement units, the area and shape of the quadrilateral (and therefore the accuracy of the calculated position) may be larger or smaller. GDOP also affects time difference of arrival systems.

Geostationary Arc

The part of the geostationary orbit that can be "seen" by, and consequently the orbital positions that can be accessed by an observer at any particular latitude and longitude on Earth.

Geostationary Orbit

Also called Geostationary Earth Orbit (GEO); a particular type of Geosynchronous Orbit that nominally is circular and lies within the plane of the Earth's equator, with a radius of 26,200 miles (22,237 miles above the Equator). Satellites are launched into in orbits to move in the same direction as the Earth revolves to have a period equal to the sidereal day of 23 hours, 56 minutes and 4.091 seconds. Ideally, as seen from Earth, the satellite remains fixed at an Orbital Position and consequently seems to be stationary in space, which gives the orbit its name. However, in practice, there are no purely geostationary orbits, principally because a satellite in orbit is subject to three forces that disturb its orbit. First, the Earth is an imperfect sphere, so its gravitational field is asymmetrical . This causes longitudinal drift of the orbital position, toward positions where the drift is zero, at 102 W and 76 E latitude. Second, the sun and the moon exert gravitational force on a satellite, which tip its orbit at an inclination to the equatorial plane at a rate of about 0.8 per year. Finally, the sun exerts radiation pressure on the satellite, accelerating it during one half of its orbit and decelerating it during the other half, with the result that the orbit becomes elliptical . If left to itself, the satellite would be moved by these forces and would gradually depart from its orbit, most likely to one of the libration points between the Earth and the Moon where forces balance and gravity is zero. Hence, keeping a satellite in geostationary orbit requires exerting some force, which in turn requires energy, which is both expensive and must be stored on board. So orbits are designed to minimize the use of energy stored on board satellites by routinely accepting deviations from the geostationary ideal. The satellite is not "stationary", but moves about in a defined box, or window determined by Station Keeping. See Geostationary Satellite.

Geostationary Satellite

A satellite with a period of revolution of one sidereal day. A satellite in geostationary orbit, also called geosynchronous orbit. A satellite placed in an geosynchronous orbit ” 22,300 miles (or 35,888 kilometers) directly over the earth's equator ” will appear to be stationary in the sky, turning synchronously with the earth. This means you can plant a satellite receiving/transmitting antenna on the ground, and point it at that one place in the sky to receive signals from and transmit signals to "the bird", as satellites are sometimes called. Most communications satellites are in geostationary or geosynchronous orbit. The Russians have some satellites that orbit the earth and require antennas which move. These satellites are used to transmit to far northern communities which are difficult to reach with normal geosynchronous satellites.

Geostationary Satellite Orbit

GSO. A satellite orbit 23,000 miles (35,888 kilometers) over the equator with an orbit time exactly 24 hours. Thus a satellite in a Geostationary Satellite Orbit appears motionless to an earth station which can receive it with a stationary antenna. One drawback is that a two-way communication channel through a geostationary satellite incurs a one-way delay, due to the finite speed of light (186,000 miles per sec) or about one-quarter second. This can be annoying because, after a pause in the conversation, the two users may start talking at about the same time and "collide" with each other, due to the fact that each started talking within a quarter second of each other.

Geosynchronous Orbit

Synchronous with the Earth. An orbit 22,300 miles (or 35,888 kilometers) above the earth's equator where satellites circle at the same rate as the earth's rotation, thereby appearing stationary to an earth-bound observer. See also Geostationary Orbit.

Geotech

Geotechnical Report. Soil boring to determine soil classification (rock, clay, etc) prior to installing the foundation for a site. See also SHPO, State Historic Preservation Officer.

GET

The standard method by which a Web browser gets information from a server. See Browser.

Get A Life

What your kids say to you when you start talking too much about the information superhighway, or the Internet, of fiber optic , or something that doesn't interest them.

GETS

Government Emergency Telecommunications Service. An integration of commercial networks to create a telecommunication backbone in case of a national disaster. GETS is a set of switch-based and Advanced Intelligent Network features that provide a high probability of completion for critical users such as the military and government before, during and after a national security emergency. GETS provides the ability to complete more authorized calls across public, defense, and federal networks in times of emergencies that include: natural disasters, military attacks, technological emergencies, or other emergencies that degrade or threaten the security of the United States. The system was developed in response to a White House executive order, and satisfies the requirements of the National Information Infrastructure (NII) and Defense Information Infrastructure (DII). GETS is paid for by the United States government. Many service providers have entered into GETS contracts with the government as this service helps facilitate additional call completions, thereby generating the potential for additional revenue.

GFC

Generic Flow Control. GFC is a field in the ATM header which can be used to provide local functions (e.g., flow control). It has local significance only and the value encoded in the field is not carried end-to-end.

GFCI

Ground Fault Circuit Interrupter. A device intended to interrupt the electrical circuit when the fault current to ground exceeds a predetermined value (usually 4 to 6 milliamps) that is less than required to operate the overcurrent protection (fuse or breaker) for the circuit. This device is intended to protect people against electrocution. It does not protect against fire from circuit overload. GFCI outlets are typically installed in bathrooms, kitchens and garages because the presence of water in these area increases the possibility of electric shock . Sometime GFCI circuits are incorrectly wired. The way to find out if your GFCI is wired correctly is to press the test button on its face. This should shut off power to the GFCI outlet and to those outlets connected to it.

GFI

Group Format Identifier. In packet switching, refers to the first four bits in a packet header. Contains the Q bit, D bit and modulus value.

GFLOPS

One billion FLoating point Operations Per Second. (G stands for GIGA, meaning billion). Today's fastest supercomputers are able to maintain a sustained throughput of over one billion floating point operations per second (GFLOPS) while performing real-world applications. By contrast, a 25-MHz 486 personal computer can sustain about one million floating operations per second (one MFLOP), or about one-thousandth the throughput of a supercomputer. See also G.

GFP

Generic Framing Procedure. GFC is a draft ANSI (American National Standards Institute) standard that defines a generic procedure for encapsulating and delineating variable-length payloads from higher-level signals for transport over a SONET (Synchronous Optical Network) or OTN (Optical Transport Network). The higher-level client payloads may be native data client PDUs (Protocol Data Units) such as Frame Relay frames, Ethernet frames, PPP (Point-to-Point Protocol) frames , or IP (Internet Protocol) packets; block-code oriented data such as Fibre Channel or ESCON; constant rate bit streams; or data character sets. GFP provides a mechanism by which that higher-level traffic is adapted to run over an octet-oriented synchronous transport network.

GFRC

Gravel Formed or Glass Fiber Reinforced Concrete building. A GRRC building is a small shelter housing telephone equipment. It's strong. One of the first users of GFRC buildings was the U.S. Military. One of the unique properties of the material used is its ability to accept multiple bullet rounds at close distances without penetration.

GFSK

The modulation technique Gaussian Frequency Shift Keying.

GFXO

Ground start FXO.

GFXS

Ground start FXS.

GGP

Gateway to Gateway Protocol. The protocol that core gateways use to exchange routing information, GGP implements a distributed shortest path routing computation.

GGSN

Gateway GPRS Support Node. An SGSN is a component sold by Ericsson, Lucent, Nokia that fit in the Mobile Switching Center of a wireless network. See GPRS.

GH Effect

Gordon-Haus Effect. The arrival time of a post-pulse soliton is a random variable governed by the medium composition/delivery, a random variable whose variance is proportional to the cube of the propagation distance.

Ghost

  1. A secondary image resulting from echo or envelope delay distortion. It can be a false radar return caused by weather effects.

  2. Ghost is also the name of Symantec software used backup and clone your PC's hard drive and easily transfer it to other PC's. It is ssed in large PC deployment and standard PC image creation.

  3. A term coined by Fluke to mean energy (noise) detected on the cable that bears similarities to a real frame, but does not include a valid start frame delimiter . To qualify for this category of error, the event must be a minimum 72 octets. Ghosts are a strong indication of a physical problem on the local segment.

Ghost Work

The unfinished projects left behind by laid-off employees. Survivors are often haunted by them.

GHz

One billion, or one thousand million, hertz, or cycles per second. See also Bandwidth.

Gi Interface

Reference point between a GPRS network and an external packet data network. See GPRS.

GID

GARP (Generic Attribute Registration Protocol) Information Declaration. See GARP for more information.

GIF

See Graphics Interchange Format.

Gig-E

Gigabit Ethernet. See Gigabit Ethernet.

Giga

From the Latin "gigas," meaning "giant." Prefix meaning one billion, which is one thousand million. 1,000,000,000. Giga is the reciprocal of nano. See also Gigabit, Gigabyte, GFLOP.

Gigabit

  1. In transmission terms, exactly one billion bits, or one thousand million bits. In the world of transmission systems, we speak of the number of bits which can be transmitted in a period of time - - specifically , one second. Hence, 1 Gbps is one billion bits per second. Let me illustrate . In eight seconds at a transmission rate of 1 Gbps, I could send you 200 copies of my dictionary.

  2. In computer terms, a Gigabit is 1024 times mega; in other words, actually 1,073,741,824. One thousand gigas are a tera. One thousand teras one peta, which is equal to 10 to the 15th.

Think of it another way, just to put it in personal perspective. If you are a Gigasecond (one billion seconds) old, you have lived to the ripe old age of 31 years, 8 months, 18 days, 18 hours, 50 minutes and 24 seconds. (Feel free to check my math.) At a rate of 1 Gbps, your entire life could flash across your network in a single second's time. Think about SONET fiber optic transmission facilities, which can operate at 2.5 Gbps or more.

See also GigaSTaR.

Gigabit Ethernet

Gigabit Ethernet (GE) is Ethernet running at one thousand million bits per second. "Normal" Ethernet runs at 10 million bits per second (10BaseT) or one hundred million bits per second (100BaseT). Gigabit Ethernet was finalized and formally approved on June 29, 1998, as IEEE 802.3z. GE is available in two flavors: shared and switched. While GE is much like traditional Ethernet, differences include frame size. As the clock speed of GE is one or two orders of magnitude greater than its predecessors, issues of round-trip propagation delay affect error detection. As a result, the minimum frame size has been increased from 64 bytes to 512 bytes. This larger minimum frame size provides more time for the transmitting device to receive a collision notification in the event of a congestion condition. The maximum frame size has been increased from 1,514 bytes to a jumbo frame size of 9,000 bytes. This frame size improves the frame throughput of a GE switch as each frame requires switch processing of header information, the fewer frames presented to the switch, the more data the switch can process, switch and deliver in a given period of time. Physical transmission media currently was originally on fiber, but GE now also works on copper . Multimode fiber will support gigabit transmission at distances up to 550 meters, and single mode fiber up to 5 km; in each case, there is a minimum distance of 2 meters dues to issues of signal reflection (echo). While UTP, STP and other electrically-based media are anticipated in the near future, distances will be limited once technical problems (e.g., signal reflection, or echo) are resolved. Cat 5 UTP is anticipated to support full-duplex transmission over distances up to 25 meters , with each of 4 pair carrying a 125-MHz signal. The application for Gigabit Ethernet largely will be in the backbone, for interconnecting lesser Ethernet hubs, Ethernet switches and high-performance servers, rather than connecting individual nodes. GE hubs and switches, however, commonly offer 10/100/1000 Mbps ports. Both half-duplex and full-duplex interfaces will be supported, with full-duplex offering the advantage of virtual elimination of issues of data collisions. Half-/full-duplex declarations will be made on a port-by-port basis. QoS (Quality of Service) guarantees are not an element of GE, by the way-ATM does that. As a practical matter, GE involves a backbone upgrade at the level of the wiring closet/data center switch. Early Gigabit Ethernet products range from $6,000-$160,000, depending on the number of Gbps- and 10/100-Mbps ports supported, the level of stackability, etc. Chassis-based systems, as opposed to standalone systems, offer advantages including hotswappable power supplies , switching matrixes , and switching modules. Gigabit Ethernet products are anticipated in the near future to achieve estimated costs of $900-$1,400 per port for shared GE, and $1,500-$3,000 per port for switched GE. Network Interface Cards (NICs), of course, will not be the same as those employed in either the 10 Mbps or 100 Mbps versions. The final result is that complete upgrades will be required at the NIC, cable and switch levels. Many users, faced with such a complete upgrade, will consider ATM as an alternative, given the Quality of Service (QoS) guarantees which ATM provides and which Ethernet does not. Additionally, ATM is more flexible, supporting voice, video and multimedia, as well as data. On the other hand, Ethernet is relatively simple and inexpensive, well understood , highly standardized, and very mature. See also ATM, Ethernet and Gigabit Ethernet Alliance.

Gigabit Ethernet Alliance

A multi-vendor forum comprised of 86 members committed to driving the industry's adoption of networking standards at up to 1,000 megabits per second. The forum supports the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol of the original Ethernet standard. According to the Alliance, gigabit Ethernet will initially be deployed in backbone environments as the preferred interconnection for switches which support multiple transmission speeds between Ethernet segments (10 Mbps and 100 Mbps). Technical proposals developed by Alliance members have been submitted to the IEEE 802.3z standards committee, furthering efforts to standardize 1,000 Mbps Ethernet technology. See Gigabit Ethernet Alliance Interoperability Consortium. www.gigabit-ethernet.org.

Gigabit Ethernet Alliance Interoperability Consortium

An organization of 15 vendor members formed within the Gigabit Ethernet Alliance for the purpose of testing the interoperability of 1Gbps products. The group will work with the University of New Hampshire Lab to conduct its interoperability tests.

Gigabits

One thousand million bits. In the U.S., that's the same as one billion bits.

Gigabyte

GB. A combination of the Greek "gigas," meaning "giant," and the English "bite," meaning "a small amount of food." A unit of measurement for physical data storage on some form of storage device-hard disk, optical disk, RAM memory etc. and equal to two raised to the 30th power, i.e., 1,073,741,824 bytes. This is the progression:

KB = Kilobyte (2 to the 10th power)

MB = Megabyte (2 to the 20th power)

GB = Gigabyte (2 to the 30th power)

TB = Terabyte (2 to the 40th power)

PB = Petabyte (2 to the 50th power)

EB = Exabyte (2 to the 60th power)

ZB = Zettabyte (2 to the 70th power)

YB = Yottabyte (2 to the 80th power)

One googolbyte equals 2 to the 100th power.

GigaE

Gigabit Ethernet. Ethernet running at the speed of one billion bits per second, which is the same as 1,000 million bits per second. See Ethernet.

Gigaflop

A unit of microprocessor processing speed equal to one billion flops, or floating point operations per second.

Gigahertz

GHz. A measurement of the frequency of a signal equivalent to one billion cycles per second, or one thousand million cycles per second.

Gigaplane

A Sun Microsystems term, Center plane bus used in Sun's Ultra Enterprise Server line. Uses separate paths of address, data, and control lines. Communicates with several subsystems concurrently. With a 167MHz UltraSPARC CPU, the Gigaplane can do rates of 2.5 Gbytes per second.




Newton[ap]s Telecom Dictionary
Newton[ap]s Telecom Dictionary
ISBN: 979387345
EAN: N/A
Year: 2004
Pages: 133

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