GIGAPOP-GR-303

GIGAPOP

A POP (Point Of Presence) with a throughput in the range of a billion (giga) packets per second. GIGAPOPs are being implemented in support of Internet2, a high-speed Internet supported by the National Science Foundation and a project of the University Corporation for Advanced Internet Development (UCAID). Internet2 uses the MCI vBNS (very high-speed Backbone Network Services) fiber optic network for transport between the GIGAPOPs, and for access to the GIGAPOPs from member universities and NSF- funded supercomputing centers. A GIGIPOP differs from a NAP (Network Access Point) in that it is a value adding, OSI layer 3 (Network Layer) meet point between customers and network providers. A NAP is a neutral, OSI layer 2 (Link Layer) meet point for ISPs (Internet Service Providers) to exchange traffic and routes.

GigaSTaR

Gigabit/s Serial Transmit and Receive. GigaSTaR is a short-haul (up to 50 meters), point-to-point communication link that transmits data with a bandwidth up to 1.32 gigabits per second over one pair of ordinary shielded twisted copper cables over 50 meters (e.g. CAT5/7) and up to 500 meters with conventional multimode fibre cable and standard optical modules. The data rate can be scaled in multiples of 1.32 gigabits per second. The link consists of two devices, the transmitter and the Receiver which convert any parallel data word with up to 36 bits and a max 33 MHz (= 148.5 megabytes per second) to a serial data stream and back to the original parallel word. Line coding reduces the overhead to 10 percent, thus 90% of the bandwidth (= 1.188 gigabit per second payload data) is available for data transmission. Applications for GigaSTaR include high-Speed scanning, printing, mass storage, security, tomography , high-speed sensoring, high-resolution camera links.

GigE

Gigabit Ethernet. See Gigabit Ethernet.

GIGO

Garbage In, Garbage Out. Regardless of the capability of the computer, bad data yields bad results.

GII

Global Information Infrastructure, a term first advocated in March, 1994 and since used as a concept around which to form many international committees . For more, see the IEEE Communications Magazine, June 1996.

Gilder's Law

Bandwidth will rise at a rate of three times the rate at which processing power is increasing, or three times the rate of Moore's Law. In other words, with processing power doubling every 18 months, bandwidth will double every six months. At the moment processing power is doubling every year and bandwidth every four months. If Kurzweil's Law holds, this rate will continue to accelerate. This law from George Gilder.

Gilder's Paradigm

The reversal of the calculus of abundances and scarcities that governed the previous era. While applied power and silicon surface area (spread over computer backplanes and motherboards and daughter cards) were abundant in the old era, they are scarce in the new era of single chip systems and mobile devices. And, while bandwidth was scarce in the old era, it is abundant in the new. While the old rule was to waste power, transistors , and silicon area to compensate for inadequate bandwidth, the new rule is to waste bandwidth to compensate for inadequate silicon area and power. This law from George Gilder.

Gillette Units

Back in the 1950s, when the laser was invented and began being experimented with, it was half-jokingly suggested that lasing power be measured in "Gillette" units, because often a laser was tested by having it burn through a razor blade .

GIM

Group Identification Mark. The Group ID mark is a two digit number used by cellular sites other than your home system to determine if your cellular phone should be allowed to make phone calls, i.e. access on "roam" status. This feature is not yet fully implemented. As cellular systems are upgraded, the GIM will be on line real time, requiring all NAM information, including the Mobile Identification Number (MIN), to be validated before a subscriber is allowed to call outside of their home area.

Gimlet

Sir T.O. Gimlette, a British navel surgeon, believed that drinking straight gin was unhealthy and impaired the efficiency of navel officers, so he began to dilute it with lime juice , hence, the Gimlet.

GIP

1. See Global Internet Project.

2. GARP (Generic Attribute Registration Protocol) Information Protocol. See GARP.

Giraffiti

The Washington Post's Style Invitational asked readers to take any word from the dictionary, alter it by adding, subtracting or changing one letter, and supply a new definition. This one is one of the winners. Giraffiti is vandalism spray- painted very high.

GIS

Geographic Information Services. Computer applications involving the storage and manipulation of electronic maps and related data. Applications include resource planning, commercial development, military mapping, etc. Raw input comes often from satellite photographs.

GIX

Global Internet eXchange. A common routing exchange point which allows pairs of networks to implement agreed-upon routing policies. The GIX is intended to allow maximum connectivity to the Internet for networks all over the world.

GK

A totally silly acronym for Gatekeeper. See Gatekeeper.

GL

Graphics Library.

Gladiator

Person engaged in a fight to the death for public entertainment in ancient Rome. See also Sensitivity Training.

Glare

Glare occurs when both ends of a telephone line or trunk are seized at the same time for different purposes or by different users. Most embarrassing ” glaringly so, in fact. Blame Ray Horak for this awful pun. See Glare Hold and Glare Release and Glare Resolution. See also Ring Splash.

Glare Hold and Glare Release

A method of glare resolution. Glare occurs when both the local and distant end of a trunk are seized at the same instant; this usually results in deadlock of the trunk. To prevent this, one end of the trunk is assigned a glare hold status and the other a glare release status. In the event of glare, the glare hold end holds the trunk and the glare release end releases the trunk and attempts to seize another. This approach is used in cellular systems between the MTSO (Mobile Traffic Switching Office) and the connecting cell sites. See also Ring Splash.

Glare Resolution

Ability of a system to ensure that if a trunk is seized by both ends simultaneously , one caller is given priority and the other is switched to another trunk. See Glare, Glare Hold and Glare Release.

Glare Window

The period of time in a trunk is susceptible to glare, a situation in which a trunk simultaneously is seized by the switches (e.g., a CO and either a PBX or ACD) at both ends. The size of the window can be reduced through ring splash and other techniques. See also Glare Hold and Glare Release, and Ring Splash.

Glass Clinking

In simpler times, it was not uncommon for someone to try to kill an enemy by offering him a poisoned drink. To prove to a guest that a drink was safe, it became customary for a host to hold out his own glass and allow the guest to pour a small amount of his drink into it. Then both would drink simultaneously. When a guest wished to show that he trusted his host, he would not pour the liquid, but simply touch the host's glass with his own. The clinking of glasses before a toast is what remains of this ritual .

Glass House

1. A colloquial word for a mainframe computer. It derives from the fact that all mainframe computers were once housed in a separate, locked room, with glass windows . You typically needed to pass through heavy security to gain admittance to the glass room.

2. A room, closet, department, floor, or entire building in which special equipment and/or procedures are implemented which allow the data processing within to proceed without interruption even if power or other services are cut off. Creating a "glass house" environment may be a simple as installing a UPS in a wiring closet or may involve providing backup power, heat, light, and telecommunications services for an entire building.

Glass Insulators

Glass insulators were widely used in the 1800s to fasten open wire to telephone poles and to protect insulator pins from moisture so they couldn't conduct electricity. This was a technique developed by the telegraph industry over a 40-year period of experimentation and was one of the few basic telegraph practices carried over into telephone line construction. Insulators are found in a variety of different shapes and colors depending on the time period they were developed and on their application. Most have a greenish color from traces of iron oxide from the sand used to make the glass. When insulator design was in its heyday in the mid-to-late 1800s, hundreds of patents to improve the product were issued. For example, the double petticoat, a second lip on the bottom of the insulator, was added to reduce the amount of moisture that could travel up the inside of the cap. The above explanation courtesy Tellabs of Lisle, IL.

Glass Mount Antenna

A type of car phone antenna used in cellular service. A glass mount antenna is glued to a car's rear window. Many window-mounted glass antennas have a break in their wiring. The wiring ends at the inside. There is no electrical connection between the inside of the window and the antenna glued onto the outside of the window. The "connection" is done through signal radiation. This type of antenna is not as efficient as one in which the wire goes unbroken from the radio to the antenna.

Glass Terminal

A keyboard and screen that conveys data generated by the user directly to a computer or network without buffering or otherwise acting upon the data, and also returns data unchanged from the computer to the user. This terminal type does not provide for cursor addressing or escape sequences.

Glazing

Corporate-speak for sleeping with your eyes open. A popular pastime at conferences and early-morning meetings. "Didn't he notice that half the room was glazing by the second session?"

Glibido

The Washington Post's Style Invitational asked readers to take any word from the dictionary, alter it by adding, subtracting or changing one letter, and supply a new definition. This one is one of the winners. Glibido means all talk and no action.

GLines

GSF Lines.

Glitch

A jargon term used in data communications to describe an extraneous bit that has been introduced into a bit stream usually by a noise source. It can also be a problem or a delay. Can be a noun. "What's the glitch?" Or a verb: "Who glitched this thing up?" Glitch is also a momentary interruption in electrical power.

Global

Universal. An adjective meaning the whole world. See Global Search.

Global 800

International toll-free numbers . See UIFN for more detail.

Global Access

A new service of MCI Mail. It allows you, an MCI Mail user, to use your computer and its modem to dial a local number in a foreign (i.e. non-North American city) and reach a port of a packet switched operation called InfoNet. When you reach InfoNet you will then punch in a few letters and reach MCI Mail in the U.S. You can then leave MCI Mail messages, send telexes, send faxes and send paper mail, i.e. do all the normal services MCI Mail allows you to do. The advantage of Global Access is that you don't have to dial back to the U.S. (which usually doesn't work because of all the garbage on the line) or subscribe to a foreign packet switched operation (they have them in all industrialized countries ). Sadly, it usually takes weeks to subscribe to a foreign packet switched operator.

Global Beam

An antenna down-link pattern used by the Intelsat satellites, which effectively covers one-third of the globe. Global beams are aimed at the center of the Atlantic, Pacific and Indian Oceans by the respective Intelsat satellites , enabling all nations on each side of the ocean to receive the signal. Because they transmit to such a wide area, global beam transponders have significantly lower EIRP outputs at the surface of the Earth as compared to a US domestic satellite system which covers just the continental United States. Therefore, earth stations receiving global beam signals need antennas much larger in size (typically 10 meters and above (i.e.30 feet and up).

Global Common and Control System.

See GCCS.

Global Directory

Imagine a bunch of local area networks all connected together. Today you log onto one server on one LAN, tell it who you are and what your password is. You want to connect to another server? You have to tell it who you are and what your password is, which may be different from the first time. Global Directory, a feature of NetWare 4.x, gives you a central directory. You establish your user name once and associated with your name is your authorized service on all the connected LANs. This way you don't have to sign on again for another server. If telephone systems can attach to NetWare (see Computer Telephony), then they should also be able to benefit from this central directory ” for phone bill allocation, people location, phone moves and changes, etc. The reason NetWare never had a central directory is historical. Novell introduced NetWare in 1983 as software to allow a handful of personal computers to share a single hard disk, which at that stage was a costly and scarce resource. As hard disks became more available, the product evolved to allow the sharing of printers and file servers. It was always designed as a departmental computing solution. It's only recently, with more powerful desktop machines, that the Client-Server LAN concept has become more corporate-wide in concept.

Global Directory Service

Allows desktop clients to transparently access data on servers across a network.

Global Internet Exchange

See GIX.

Global Internet Project

GIP. Comprised from a group of senior executives, representing sixteen leading Internet software, telecommunications and digital commerce companies worldwide. Its purpose is to promote the growth of the Internet across geographic boundaries worldwide. Explores present and future impact of the Internet upon commerce and society.

Global Login

A mechanism that permits users to log on to the network, rather than repeatedly logging on to individual servers. A global logon can provide access to all network resources.

Global Maritime Distress and Safety System

See GMDSS.

Global Mobile Personal Communications Services

GMPCS. A term coined by the ITU-T to refer to satellite telephony to be provided by the proposed Big LEO (Low Earth-Orbiting Satellite) systems such as Teledisc and Globalstar and MEO (Middle Earth-Orbiting Satellite) systems such as ICO and Odyssey.

Global Network

An international network that spans all departments, offices, and subsidiaries of the corporation. Global networks bring their own set of problems, including those of different time zones, languages, established standards, and PTT (Postal Telephone and Telegraph) companies.

Global Network Navigator

GNN. An application developed at CERN in Switzerland which provides information about new services available on the Internet, articles about existing services, and an online version of Internet related books. The GNN is a World Wide Web (WWW) based information service.

Global One

A joint venture of Deutsche Telekom, France Telecom, and Sprint. Launched in January 1996, Global One provides Virtual Network Services (VNS) in more than 65 countries. See also VNS.

Global Positioning System

See GPS.

Global Roaming

When you go traveling, you want access to the Internet, preferably by making a local phone call. This capability is called global roaming.

Global Search

A word processing term meaning to automatically find a character or group of characters wherever they appear in a document.

Global Search and Replace

A word processing term meaning to automatically find a character or group of characters wherever they appear in a document and replace them with something else.

Global Security Service

Provides networkwide security functions, including single log-in to multiple systems.

Global Subscriber Number

GSN. See UIFN.

Global Switched Telephone Network

See GSTN.

Global Title

GT. An address such as customer- dialed digits that does not explicitly contain information that would allow routing in the SS7 signaling network, that is, the GTT (Global Title Translation) function is required. See Global Title Translation.

Global Title Translation

GTT. The process of translating a Global Title from dialed digits to a point code (network node) address and application address (subsystem number). This process is accomplished by the STP (Signal Transfer Point) in the SS7 network. GTT is defined in IS-41B. See also IS-41, Global Title, SS7 and STP.

Global Transaction Network

See GTN.

Global Village

A term coined in the 1960s by Marshall McLuhan, who wrote a number of very popular books, including "The Medium is the Massage," "War and Peace in the Global Village" and "The Gutenberg Galaxy; The Making of Typographic Man." McLuhan coined the term to foreshadow a world of personal computers joined together over a global network. In short, he was talking about the Internet, though he didn't know about it at the time. It was just starting.

Globally Unique Identifier

GUID. Also known as Universally Unique IDentifier (UUID). An identifier (ID) is a numeric or alphanumeric string of characters or bits. A Globally Unique Identifier is unique in all the world, or is highly unlikely to be duplicated . A GLID generally is understood by all systems, rather than being proprietary in nature, and often is controlled at some level by a centralized registration authority. URLs (Uniform Resource Locators), which we use to locate resources on the World Wide Web (WWW) are GUIDs; www.telecombooks.com is an example. ISBNs (International Standard Book Numbers) and SSNs (Social Security Numbers) also are examples of GUIDs.

In the context of computing and computer communications, GUIDs are 128-bit identifiers that are unique in both space and time. GUIDs identify objects (e.g., your computer, a piece of software code, or an application software program) to the network. GUIDs originally were developed Apollo as part of its NCS (Network Computing System) for making RPCs (Remote Procedure Calls) from a terminal to a host. Subsequently, the GUID concept was adopted by the OSF (Open Software Foundation), of which Apollo was a founding member. Generally speaking, GUIDs are based on the IEEE 802.1 LAN (Local Area Network) addressing scheme, with the IEEE serving as a central registration authority for numbering LAN nodes through hard-coded IDs stamped on LAN NICs (Network Interface Cards). If an 802.1 NIC is not in place, some other mechanism is used either to generate a random number identifier, or make use of some other system attribute or characteristic. The GUID also contains several timestamp fields, which rely on timing mechanisms (i.e., clocks) embedded in the host systems and represented by UTC (Universal Time Coordinated).

Microsoft got a lot of attention through its use of GUIDs associated with Windows 98. According to Microsoft, that particular GUID was used to track your progress through the www.microsoft.com website, much like a cookie. The GUID also embedded hidden code in Word and Excel files, thereby allowing the original author of a document to be identified through a hardware identification number. This became a huge privacy issue. See also Cookie, NIC, OSF, RPC, URL, and UTC.

GlobalNet

A free, electronic amateur bulletin board system network which operates based upon FidoNet technical standards. GlobalNet nodes are located in North America and Europe.

Globalstar

Imagine a hand-held, light, low-cost telephone that looks like a cell phone, but works by talking to a satellite. Several companies have proposed a collection of low-orbiting satellites. The idea is that the closer the satellite, the stronger the signal on the ground, and the smaller the size of the telephone. The low earth orbit also reduces propagation delay, which plagues communications using GEOs (Geosynchronous Earth Orbiting Satellites), which are in equatorial orbits at altitudes of approximately 22,300 miles (35,888 kilometers). Companies proposing such systems include Teledesic and Globalstar.

Globalstar is a Low Earth-Orbiting (LEO) satellite-based digital telecommunications system that will offer wireless voice, fax, low-speed data, messaging and position location services worldwide. Globalstar service will be delivered through a 48-satellite LEO constellation (plus 4 backup satellites) at an orbital altitude of 1,414 kilometers (877 miles). In total, the constellation will provide wireless telephone service in virtually every populated area of the world where Globalstar service is authorized by the local telecommunications regulatory authorities. (Globalstar service providers will be required to obtain such approvals before beginning to offer Globalstar service in their territories .) The system will work on a "bent-pipe" signal relay scheme in which the call is launched from a terrestrial wireless device (e.g., wireless phone or data terminal) directly to the satellite. The satellite, with minimal processing, will relay the call to a gateway groundstation (i.e., authorized service provider's satellite dish) for connection to the destination device over the existing local terrestrial wireline or wireless network.

Users of Globalstar will make or receive calls using hand-held or vehicle-mounted terminals similar to today's cellular telephones; fixed wireless terminals (e.g., wireless pay phones) also will be supported. Because Globalstar will be fully integrated with existing fixed and cellular telephone networks, Globalstar's dual-mode handsets units will be able to switch from conventional cellular telephony to satellite telephony as required. In remote areas with little or no existing wireline telephony, users will make or receive calls through fixed-site telephones, similar either to phone booths or ordinary wireline telephones.

Globalstar planned to begin launching satellites in the second half of 1997, and to commence initial commercial operations via a 24-satellite constellation in 1998. That didn't happen. The first eight satellites were launched in 1998. The second launch of 12 satellites was a failure. An additional 24 satellites are expected to be launched by May 1999, and commercial service will be initialized in Fall 1999. Full 48-satellite coverage will occur sometime in the future. Based in San Jose, California, Globalstar is a limited partnership founded by Loral Corporation of New York City, and QUALCOMM Inc., of San Diego, California. Strategic partners represent the world's leading telecommunications service providers and equipment manufacturers. See also GEO, LEO and Propagation Delay.

Globus

A collaborative academic project centered at Argonne National Laboratory focused on enabling the application of grid concepts to computing.

GLONASS

The Russian Global Navigation Satellite System is similar in operation and may prove complimentary to the American NAVSTAR system. Launched in 1996, it is a 24 satellite constellation 19,100 Km above the earth in three orbital planes.

Glovebox User

After the September 11, 2001 World Trade Center disaster, there was a huge boom in the purchase of cell phones. Many of these phones were for using only in emergencies, for keeping in the glovebox of the car. Hence the name of the person who uses them, a glovebox user.

Gubment

Slang for government.

Glue Logic

A generic term for program logic or a protocol that interconnects physical or logical units. For example, glue logic is used to interface microcontrollers with external memory. Glue logic is used by system designers to connect VLSI (Very Large Scale Integrated) circuits. "Blue Glue" is IBM's SNA (Systems Network Architecture). See also Glueware and Systems Network Architecture.

Glueman

A glued-shut Sony discman that contains a pre-release CD. As The New York Times noted, the device is designed to "keep writers from converting the music to MP3s that can then be traded over the Net."

Glueware

The trend of joining software applications to physical networks through the deal AT&T and Novell have struck to adapt Novell local area networking software to communicate over AT&T's long-distance network. Intel and Microsoft are considering similar arrangements, according to The Wall Street Journal.

GMD

Gesellschaft fur Mathematik und Datenverarbeitung: a German government computer science research institute.

GMDSS

The Global Maritime Distress and Safety System, a worldwide radio system for distress and safety at sea. Under the provisions of the Safety Of Life At Sea (SOLAS) convention and the International Maritime Organization (IMO), after 1 February 1999, GMDSS is mandatory for all cargo ships over 300 tons and for all passenger ships on international voyages, regardless of size. GMDSS overcomes the weaknesses of limited range, limited communication and high probability of human error of the traditional Morse telegraphy and radiotelephony used round the world up to February 1, 1992 when GMDSS first became operational. GMDSS covers the globe in four defined sea areas. A1: coastal areas within radiotelephone coverage of at least one VHF coast radio station providing continuous digital selective calling (DSG), usually no more than 30 nautical miles from shore and mostly serving coastal shipping. A2: beyond A1 but within radiotelephone coverage of at least one medium-frequency (MF) coast radio station providing DSG, usually no more than 150 nautical miles from shore and similar to traditional ship radio services. A3: beyond A1 and A2 and within the coverage of geostationary satellites providing continuous service round the globe from 70 S to 70 N latitude for 360 azimuth free sight at 5 ship satellite antenna elevation and provided by the Inmarsat-A, B, C and E systems. A4: beyond A1, A2 and A3 and comprising the polar regions beyond 70 latitude and served by Arctic and Antarctic radio stations as well as by satellites in polar orbits, including COSPAS-SARSAT. For further info , visit www.imo.org and/or see COSPAS-SARSAT, DSG, ELT, EPIRB, NAVAREA, NAVTEX and SART.

GMP

Global Managed Platform.

GMPCS

Global Mobile Personal Communications Services. A term coined by the ITU-T to refer to satellite telephony to be provided by the proposed Big LEO (Low Earth-Orbiting Satellite) systems such as Globalstar, and MEO (Middle Earth-Orbiting Satellite) systems such as ICO and Odyssey. See Globalstar.

GMPLS

Generalized Multiprotocol Label (Lambda) Switching. From the www.mplsrc.com web page: GMPLS represents a natural extension of MPLS to allow MPLS to be used as the control mechanism for configuring not only packet-based paths, but also paths in non-packet based devices such as optical switches, TDM muxes, and SONET/ADMs." In short, all of the mechanisms that allow MPLS to be used as a viable solution for Traffic Engineering.

GMRP

GARP (Generic Attribute Registration Protocol) Multicast Registration Protocol is a mechanism by which bridges and end stations can automatically and dynamically register their membership in a group with the MAC bridges by which a physical LAN segment attaches to the larger logical LAN. See GARP for more information.

GMRS

General Mobile Radio Service.

GMSC

Gateway Mobile services Switching Center. A wireless telecommunications term. A means to route a mobile station call to the MSC (Mobile Switching Center) containing the called party's HLR (Home Location Register).

GMSK

Gaussian Minimum Shift Keying. A wireless telecommunications term. A means of radio wave modulation used specifically in the GSM (Global System for Mobile Communications) air interface.

GMT

Greenwich Mean Time, sometimes known as Greenwich Meridian Time and World Time. Local time used to be good enough. International shipping changed all of that many years ago, creating the need for a global standard and reference point. GMT was created in October 1884 to satisfy that need, with the reference being the average (i.e., mean) time it takes the earth to rotate from noon-to-noon as measured from the Greenwich Meridian Line, or prime meridian, which runs through the principal Transit Instrument at the Royal Observatory in Greenwich, England. The Greenwich Meridian Line is used as it is at zero degrees longitude, thereby serving as the reference point for all measurements of longitude. Although GMT technically has been replaced by Coordinated Universal Time (UTC), it still is widely regarded as the correct time for every international time zone. See also UTC (now called Coordinated Universal Time) and Zulu Time.

GNCT

Generalized No Circuit Treatment.

GND

Ground.

GNE

Gateway Network Element. A SONET Network Element (NE) that provides a direct OS/NE interface. The GNE provides an indirect OS/NE interface. The GNE provides an indirect OS/NE interface for other NEs in its own management subnetwork.

GNMC

Global Network Management Center.

GNN

See Global Network Navigator.

GNOME

GNU Object Model Environment. Pronounced "guh-NOME." A graphical, Windows-like desktop environment designed to be used on multiple GNU (GNU's Not UNIX) platforms. Like GNU, GNOME is distributed without cost (i.e., free) on the basis of an open license. GNU, by the way, is a recursive acronym. See also Acronym and GNU.

GNU

A recursive acronym for GNU's Not UNIX. Pronounced "ghu-NEW." Note: A recursion is a procedure of mathematics or grammar that can repeat itself indefinitely until a specified or desired condition is met. The GNU Project of the Free Software Foundation was launched in 1984 at MIT (The Massachusetts Institute of Technology) by Richard Stallman to develop a freeware UNIX-like operating system. Variants of GNU that use the Linux kernel sometimes are known as GNU/UNIX or Linux/GNU. See also Acronym.

GNX Development Tools

A set of fax software development tools offered by National Semiconductor.

Goat

1. Also called Craft test Set or Butt Set. A telephone used to test analog phone lines.

2. A hairy animal that can become nasty when upset, like telephone customers who have a problem with their phone lines.

3. People in our population whose voices cannot ” under any circumstances ” be recognized by voice recognition machines.

4. In biometric verification, a goat is a system end-user who is refused access to the system because their biometric data pattern is outside the range recognized by the system. The term comes from a research paper on speech recognition published in 1998 by George L. Doddington. The paper, "Sheep, Goats, Lambs and Wolves - An Analysis of Individual Differences in Speaker Recognition Performance" used a menagerie analogy to explain the differences in speech recognition. Sheep were speakers whose voice patterns were easily accepted by the system, goats were speakers who were exceptionally unsuccessful at being accepted, lambs were speakers who were exceptionally vulnerable to impersonation, and wolves were speakers who were exceptionally successful at impersonation. Because false rejection rates are often high when testing a biometric verification system, goats are probably better known than the other animals in Doddington's menagerie.

Go Gold

Finish that particular release of a software program and release it to manufacturing, i.e. send it the company who's going to duplicate the disk, print the manuals, bundle the whole package and shrinkwrap it all.

Go Local

A command typically given in a asynchronous data communications program to tell the computer that it will connect to something without a modem over a null modem cable. The command "Go Local" also refers to modem connections and can tell one modem to overlook some of the handshaking and assume it's already taken place.

GO-MVIP

Global Organization for MVIP. GO-MVIP is a non-profit trade association established in 1993 to move the Multi-Vendor Integration Protocol standards forward. The stated goals of GO-MVIP are to 1) Develop and establish design specifications for further enhancements of MVIP, 2) Drive MVIP to an official industry standard, 3) Establish a testing laboratory and quality assurance program for current and future MVIP products, and 4) Ensure the continued growth and long-term success of MVIP. As of July 1996, GO-MVIP comprises 170 members ; over 300 MVIP-compliant products exist. www.mvip.org. See MVIP.

God

In 1970, an Arizona Lawyer named Russel H. Tansie filed a $100,000 damage suit against God. The suit was filed on behalf of his secretary, Betty Penrose, who accused God of negligence in His power over the weather when He allowed a lightning bolt to strike her home. Ms. Penrose won the case when the Defendant failed to appear in court . Whether or not she collected has not been recorded.

God Games

Computer games, also called simulators, in which the player manages a complex system of interacting variables , inputs and agents . There are games that let you simulate railroad empires, manage city government, enlarge tropical dictatorships, expand golf resorts and countless other worlds .

GOF

Glass Optical Fiber. This may seem obvious, but there also is something called Plastic Optical Fiber (POF). See Fiber Optics and POF.

Going Cyrillic

Going cyrillic is when a graphical display (LED panel, bit-mapped text and graphics) starts to display garbage. "The thing just went cyrillic on me."

Going Postal

Euphemism for being totally stressed out, for losing it. Makes reference to the unfortunate track record of postal employees who have snapped and gone on shooting rampages.

GOLAY

One of the communications protocols used between paging towers and the mobile pagers /receivers/beepers themselves . Other protocols are POCSAG, ERMES, FLEX and REFLEX. The same paging tower equipment can transmit messages one moment in GOLAY and the next moment in ERMES, or any of the other protocols.

GOLD

An EBPP (Electronic Bill Presentation and Payment) specification developed for billing and payment over the Internet. GOLD was developed by Integrion Financial Network, which is owned by VISA USA, IBM and a number of banks. GOLD was designed to support the display and manipulation of financial data such as bank account information and stock holding, and funds transfer. GOLD also supports transactional Web sites. The competing specification is OFX (Open Financial Exchange). See also Electronic Commerce and OFX.

Gold Bar

Alok Das of the Pentagon's Space Vehicle's Directorate claims "it costs a bar of gold to launch a can of Coke" as a satellite into space.

Gold Codes

Named after Robert Gold, Gold codes are used in direct-sequence spread spectrum transmission. Each transmitted signal is assigned to unique Gold code, which correlates the original information signal into a pseudo random sequence. This sequence is then modulated and transmitted as a spread spectrum signal. The receiver, which uses the same Gold code, is able to de-correlate the spread spectrum signal and recover the original information. Gold codes possess two very desirable qualities which are important in a high quality communications system. The first quality is called "auto-correlation." When a receiver is subjected to several spread spectrum signals, it must extract the desired information and reject the remainder. Auto-correlation allows for an excellent signal recovery when the transmitted code matches the reference code in the receiver.

The second quality is called "cross-correlation." Cross-correlation simply means that an undesired transmitted code cannot produce a false match at the receiver. The advantage of Gold codes is that they consistently exhibit superior cross-correlation performance, which is critical in an environment with multiple transmitters, each representing a potential interfering source. See Spread Spectrum.

Gold Disk

You have finally finished your new software. And you're now ready to go into production, to have your software reproduced onto disks you can sell. That final, completed version of software, from which you reproduce commercial production disks, is called your "Gold Disk." From what I can see, it's a "Gold Disk," though there may be more than one disk in your package.

Gold Number

Also called vanity number. It's a phone number that's easy for your customers to remember, e.g. 555-LIMO. But occasionally hard for them to dial. Tip: If you buy a vanity number, make sure it doesn't have numbers in it. 555-LIMO is harder to remember than CAR-RENT.

Golden Egg

"That's the way with these directors. They're always biting the hand that lays the golden egg." Samuel Goldwyn, film producer.

Golden Gate Bridge

The first year the Golden Gate Bridge in San Francisco was open, it carried 3.5 million vehicles. Today, it carries close to 40 million. It cost $35 million to build with the construction bonds being paid off in 1971. The replacement cost is estimated to be about $1.3 billion. Bridges are not paid investments. May I sell you one?

Golden Parachute

When a senior executive gets fired from his company, he is often given lots of money (thus golden) by the board to make his landing outside the company soft (thus parachute). See also Golden Rolodex.

Golden Rolodex

The small handful of experts who are always quoted in news stories and asked to be guests on TV discussion shows. Example: Henry Kissinger appears to be in The Golden Rolodex under foreign policy.

Goldwyn, Samuel

Famous film producer. He was born Shmuel Gelbfisz in Warsaw, Poland. He made great movies and great aphorisms, known affectionately as Goldwynisms: Samples: "A verbal contract isn't worth the paper it's written on." "A hospital is no place to be sick." " Anyone who goes to a psychiatrist ought to have his head examined." "I had a great idea this morning, but I didn't like it." "Gentlemen, include me out." "A wide screen just makes a bad film twice as bad." "I can give you a definite perhaps." "I can tell you in two words: im possible." "I paid too much for it, but it's worth it." "If I could drop dead right now, I'd be the happiest man alive ." On a film set of a tenement: Goldwyn: Why is everything so dirty here? Director: Because it's supposed to be a slum. Goldwyn: Well, this slum sure cost a lot of money. It should look better than an ordinary slum." "Pictures are for entertainment. Messages should be delivered by Western Union." "I don't want yes-men around me. I want everyone to tell me the truth, even if it costs them their jobs." "If I look confused , it's because I'm thinking." "Why did you name him Sam? Every Tom, Dick and Harry is named Sam." "I don't think anyone should write his autobiography until after he's dead." "You fail to overlook the crucial point."

Golf

If you have ever wondered why you play 18 holes and not 20, or 10 or an even dozen in golf, the reason is simple ” and logical. During a discussion among the club's membership board at St. Andrews in 1858, a member pointed out that it takes exactly 18 shots to polish off a fifth of Scotch. By limiting himself to only one shot of Scotch per hole, the Scot figured a round of golf was finished when the Scotch ran out.

Gonk

On-line jargon. It means To prevaricate or to embellish the truth beyond any reasonable recognition. "You're gonking me. That story you just told me is a bunch of gonk."

Good, Dan

Former Wall Street executive who was singed, not burned by the High Tech Bubble. He knew the bubble would burst but was na ”ve enough to think he could safely traverse the profit wave and land safety in calm water on the other side. The IPO surf board he was riding got swept under like all the other amateur surfers as the wave came crashing down. The little high tech knowledge he acquired proved dangerous, but fortunately not lethal. Today, older but wiser, he is an evangelist of cash. He is most well known for uttering the now famous phrase, "Sue the bastards". I am proud to be his friend. Dan is teaching me enough about investing to be dangerous, just like him.

Good Condition

A term used in the secondary telecom equipment business. One step up from fair condition. Product is in working condition and looks good.

Goodwill

Goodwill is a term you'll find on balance sheets. It represents the difference between what a company paid to buy other companies and what those other companies' assets were valued at on their books. If a company pays a lot of money to acquire another company, then its balance sheet will have a high number for "goodwill." That number is carried as an asset on its balance sheet. But is it really an asset or not? That can only be answered by guessing whether the asset can be sold at at least what the company originally paid for it. The issue of goodwill became very important in the telecom industry after AT&T paid $50 billion to buy a bunch of cable TV companies in the hope that they would provide a local loop to the consumer. As time passed, AT&T's $50 billion looked like an increasingly stupid decision. And the value of the goodwill on AT&T's balance sheet looked increasingly valueless. (You know what I mean.)

Gooey Interface

A slang way of saying graphical user interface. See GUI.

Google

Google is arguably the world's best search engine. It was founded by two Stanford graduates, Larry Page and Sergey Brin. They understand the true secret of sustainable success. When asked at a Wall Street Journal D Conference, "How do you get better than you already are?" by a devoted fan in the audience, Page replies, "You may think using Google's great, but I still think it's terrible." In fact, Page won't rest until Google can produce "the exact right answer instantly about everything in the world."

Googol

A term coined in 1929 by Milton Sirotta, an American mathematician , a googol is a number expressed as 10 followed by 100 zeroes, i.e., 1 to the 100th power. See Googolbyte.

Googolbyte

Two raised to the power 100. See Byte for a full transition to Googolbyte.

Googolplex

A googolplex is 10 to the power of a googol, which is 1 followed by 10 to the power of 100 zeros. Frank Philhofer has determined that, given Moore's Law (which is that computer processor power doubles about every 18 months or so), it would make no sense to try to print out a googolplex for another 524 years ” since all earlier attempts to print a googolplex out would be overtaken by the faster processor. I'm not too sure what all this means, but it sure sounds incredible.

Goodput

The amount of good data that is put through a network. Goodput commonly is used to describe throughput in ATM and other packet networks. Throughput is the end result of a data call, as measured by the relationship of what went in one end and what came out the other. Throughput, therefore, is a measure of the efficiency of that communications network. Throughput is a function of bandwidth, error performance, congestion, and other factors. In an ATM network, goodput excludes duplicate cells and packets. Goodput also excludes ATM cells that cannot be reassembled at the receiving node into a complete and meaningful data packet, which was segmented at the transmitting node. See also Throughput.

GOP

Grand Old Party. Another way of saying the Republican Party. In December of 2002, the Wall Street Journal stopped referring to the Republican Party as the GOP. Now they're just the Replublican Party.

Gopher

Programmers at the University of Minnesota ” home of the Golden Gophers ”- developed a kind of menu to "go for" items on Internet, bypassing complicated addresses and commands. If you want to connect to the State Library in Albany you select that option off the menu. Time Magazine once described Gopher as a tool used for "tunneling quickly from one place on the Internet to another." Hence the term Gopher. See also Gopherspace.

Gopherspace

The vast number of servers and areas of interest accessible through the Internet gopher. See Gopher.

GORIZONT

The Russian geostationary telecommunications satellite.

GOS

Grade of Service. Telecom traffic term. The probability that a random call will be delayed, or receive a busy signal, under a given traffic load.

GOSIP

Government Open Systems Interconnection Profile. The U.S. government's version of the OSI protocols. GOSIP compliance is typically a requirement in government networking purchases. GOSIP addresses communication and inter operation among end systems and intermediate systems. It provides specific peer-level , process-to-process and terminal access functionality between computer system users within and across government agencies.

Gotcha Law, The

This law comes from "Got You." It's my favorite law. Think about life. You buy a beautiful laptop. You fall in love with it. You want to buy one for your wife. When you go back to the store all hot to do your wife a wonderful favor, they tell you, "Sorry, it's been discontinued." Gotcha! Compare with Murphy's Law.

Government Radio Publications

Publications on radio subjects by the Bureau of Standards and Signal Corps and sold by the superintendent of Documents, Government Printing Office, Washington D.C.

GPA

General Purpose Adapter. An AT&T Merlin device that connects an analog multi line telephone to optional equipment such as an answering machine or a FAX machine.

GPB

Grand Pooh-Bah. Pooh-Bah is a character in Gilbert and Sullivan's opera "The Mikado." Pooh-Bah held the title "Lord-High-Everything-Else." Ray Horak, my Contributing Editor on this book, is the President and GPB of The Context Corporation, or so his e-mail sig says. It's his company, so I guess he can give himself any title he likes. Ray says it's just a joke, but hardly anyone notices or asks what GPB means. In fact, several of the conference brochures that promote his tutorials and other presentations list him as President and GPB.

GPC

Gateway Protocol Converter. An application-specific node that connects otherwise incompatible networks. Converts data codes and transmission protocols to enable interoperability. Contrast to Bridge.

GPCL

General Premises Cabling Licence.

GPF

General Protection Fault. A problem that happens too often under Windows 3.xx. 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.

GPI

GammaFax Programmers Interface. C-level programming language. Real-time applications for fax switched and gateways.

GPIB

An interconnection bus and protocol that allows connection of multiple instruments in a network under the direction of a controller. Also known as the IEEE 488 bus, it allows test engineers to configure complete systems from off-the-shelf instruments and control those systems with a single, proven interface. GPIB was originally called HPIB because it was developed by Hewlett Packard.

GPOP

Global Point of Presence.

GPRS

Want to connect your laptop to your cell phone and surf the web or send emails? GPRS is for you. GPRS stands for General Packet Radio Service. And it's the always-on packet data service for GSM, which is the cell phone standard which most countries of the world use, including Europe, Australia, America (not all carriers ) and some parts of Asia. The idea is that you'll connect your GPRS-equipped (also called 2.5G) cell phone to your laptop with a cable or insert a small GPRS-equipped PCMCIA card into your laptop and transmit. GPRS will be most useful for " bursty " data applications such as mobile Internet browsing and e- mail. GPRS has been demonstrated as fast as 115 Kbps. And in theory it can go that fast. But the reality is that you'll get between 20Kbps and 50Kbps throughput ” about the speed you get from your dial-up home landline . One big advantage of GPRS is that it's "always on," just like your DSL line, your cable modem or your office network. To send a data message you won't have to waste a minute dialing a number and listening to the modems go through their interminable screeching/connect dance . GPRS is the primary feature of what has become known as 2.5G ” the upgrade to today's 2G cell phone network. 1XRTT is the CDMA equivalent of GPRS. See GSM and HSCSD.

GPRS introduces two new network nodes in the GSM Public Land Mobile Network (PLMN): The Serving GPRS Support Node (SGSN), which is at the same hierarchical level as the mobile services switching center (MSC), keeps track of the location of the individual mobile stations (MSs) and performs security functions and access control. The SGSN is connected to the base-station system via Frame Relay. The GGSN provides interworking with external packet-data networks, and is connected with SGSNs via an IP-based GPRS backbone network. Also (from TCP): RTO Retransmission Timeout - A value that triggers packet resend in TCP-IP if no acknowledgement is received, because the protocol assumes the packet has been lost. RTT Round Trip Time (Time required from emission of a packet until an acknowledgement is received. This helps determine the adaptive characteristics of the TCP protocol.

GPS

1. Global Positioning System. A constellation of 24 orbiting satellites system which allow all of us to figure out precisely where we are anywhere on earth to within one meter's accuracy, both height and longitude/latitude. The GPS consists of a constellation of 24 satellites orbiting the earth at 10,900 miles. Each satellite orbits the earth twice a day. Think of them as "man-made stars" to replace the stars that we've traditionally used for navigation. The U.S. Government has over $10 billion to build and maintain the system. Each GPS satellite transmits radio waves on two frequencies: 1575.42 MHz referred to as L1, and 1227.60 MHz referred to as L2. It transmits a host of somewhat complicated data occupying about 20 MHz of the spectrum on each channel. But basically, it boils down to three items. The satellite transmits its own position, its time, and a long pseudo random noise code (PRN). The noise code is used by the receiver to calculate range. If we know precisely where a satellite is located and our precise distance from it, and if we can obtain similar readings from other satellites, we can calculate precisely our own location and altitude by triangulation. Satellite position and time are derived from on-board celestial navigation equipment and atomic clocks accurate to one second in 300,000 years. But the ranging is the heart of GPS. Both in the receiver, and in the satellite, a very long sequence of apparently random bits are generated. By comparing internal stream of bits in the receiver to the precisely duplicate received bits from the satellite, and "aligning" the two streams, a shift error or displacement can be calculated representing the precise travel time from satellite to receiver. Since the receiver also knows the precise position of the satellite, and its range from the receiver, a simple triangulation calculation can give two-dimensional position (lat/long) from three satellites and additional elevation information from a fourth.

   There are actually two PRN strings transmitted: a coarse acquisition code (C/A code) and a precision code (P code). The coarse code sequence consists of 1,023 bits repeated every 266 days. But each satellite transmits a seven day segment re-initialized at midnight Saturday/Sunday of each week. By using both codes a very accurate position can be calculated. By transmitting them at different frequencies, even the signal-attenuating effects of the ionosphere can to some degree be factored out. At the present time, civilian users are only authorized to use the coarse acquisition code, which is the basis for the GPS Standard Positioning Service (SPS), and which yields a best accuracy of about one meter. Military users use both the coarse acquisition code and the precision code in what is referred to as the Precise Positioning Service (PPS), which yields accuracy to within centimeters. The Department of Defense (DOD) can at any time encrypt the precision code with another secret code. This process of " anti-spoofing " ensures that no hostile military forces can also use the GPS service at that time. The DOD can also purposely degrade the accuracy of the coarse acquisition code, in a process known as "selective availability," to degrade accuracy to about 100 meters. But other than during brief test periods and national emergencies, the service is generally available to all. New techniques now make the civilian use of GPS almost as accurate as the military use. The accuracy of any given GPS receiver at any point in time depends on how many GPS satellite signals it can acquire. Some low-cost receivers can pick up five satellites and are thus accurate to within one meter.

   That's not the end of the story, however. Regardless of the sophistication of a given GPS receiver, satellite signals can be difficult, if not impossible , to acquire in certain places such as canyons (either natural or of the man-made urban sort ), indoors, in vehicles, in shaded areas such as under trees or canopies, or in other areas where the signals are too noisy , attenuated (i.e., weakened), or distorted by multipath fading. If, however, the GPS receiver is integrated into a cell phone, pager, PDA, or other device running over a terrestrial wireless network, that network can assist in the GPS process by providing additional data. This technique of Assisted GPS (AGPS), also known as Wireless Assisted GPS (WAGPS), can involve several alternative approaches. One such approach involves a special chipset built into the wireless device. That chipset accepts signals from both the GPS satellites and the base stations of the cellular network, correlates the information, and thereby informs the network of its location with an accuracy of several meters. Additional intelligence in network-based servers can further refine that location data. An alternative approach is entirely network-based, and does not involve additional intelligence embedded in the handset. This latter approach uses signal strength information derived from multiple network base stations to triangulate on the location of the terminal device. That information is correlated with the specific GPS data that pinpoints the location of the base stations, themselves. AGPS, which is relatively new and certainly not universally available, is critical to the delivery of location-based services. Such services allow the network to pinpoint your location in order to provide you with information such as a list of nearby Thai restaurants , and directions to the one you select. More importantly is the ability of AGPS to pinpoint your location for emergency purposes. E911 (Enhanced 911) service providers increasingly will depend on AGPS in order to render all sorts of emergency services more effectively and more quickly. The FCC has rules that in October of 2001, at least half the mobile phones being sold in the U.S. must be 911 location service equipped. See also Galileo, the proposed European GPS.

2. Navstart Global Positioning Satellite. Used by networks for synchronization.

GR

Generic Requirement. A Bellcore (now Telcordia) document type replacing the Framework Technical Advisory (FA), Technical Advisory (TA) and Technical Reference (TR) document types. FA, TA and TR documents previously reflected the maturity level of the proposed requirements. In contrast, a Generic Requirements (GR) is a living document that represents Telcordia's preliminary and current view of a technology, equipment, service or interface. It does not necessarily reflect the views of any other company. See GR-303.

GR-1209

Telcordia generic requirements for fiber optic branching components .

GR-1221

Telcordia generic reliability assurance requirements for fiber optic branching.

GR-196

Telcordia generic requirements for optical time domain reflectometer (OTDR) type equipment. See GR.

GR-20

Telcordia generic requirements for optical fiber and fiber optic cable. See GR.

GR-303

GR-303 is a set of technical specifications from Telcordia to help define what the next generation of the world's telecommunications network (i.e. the new PSTN) might look like. The following words are from Bellcore (now Telcordia):

"What is GR-303? Network providers are looking to deploy Next Generation Integrated Digital Loop Carrier (NG-IDLC) systems that take advantage of leading edge technology to help reduce operating and capital equipment costs while delivering a full range of telecommunications services. Telcordia's GR-303 family of requirements specifies a set of NG-IDLC generic criteria that creates an Integrated Access System, supporting multiple distribution technologies and architectures (e.g., xDSL, HFC, Fiber-to-the-Curb, etc.), and a wide range of services (narrowband and broadband) on a single access platform. The GR-303 family of generic criteria defines a set of requirements for Integrated Access Systems that includes open interfaces for mix-and-match of (1) Local Digital Switches (LDSs) with Remote Digital Terminals (RDTs) as well as (2) RDTs and Element Management Systems (EMSs). Facilities connecting to the narrowband digital switch (i.e., LDS) are efficiently assigned and managed through the Time-Slot Management Channel (TMC), with remote operations functions supported over the Embedded Operations Channel (EOC) of the GR-303-based Integrated Access System. GR-303-based Integrated Access Systems promote increased network architecture flexibility by providing a consistent approach to deploying a wide range of access system technologies in a consistent manner. Many vendors are developing NG-IDLC products that, although they use different distribution technologies and architectures (e.g., hybrid fiber coax and fiber in the loop), meet the open interfaces described in the GR-303 requirements. This allows network providers to tailor the access system technology deployed area-by-area while utilizing core network features such as the LDS interface and Telecommunications Management Network (TMN) operations capabilities. GR- 303-based Integrated Access Systems are intended to reduce capital costs through supplier competition and operating costs through a standards-based, Telecommunications Management Network (TMN) compatible operations environment that provides remote operations capabilities. Integrated Access System products will help to reduce capital costs by enabling mix-and-match among LDS, RDT and EMS products from a wide variety of vendors. The open interfaces described in the GR-303 requirements will help enable the network providers to pursue competitive bids from multiple suppliers for Integrated Access Systems products, thereby potentially obtaining better prices." For more: www.telcordia.com/resources/genericreq/gr303/index.html

According to a company called Zarak Systems Corporation, a maker of bulk call simulator GR-303 test equipment, "GR-303 is a specification for a digital loop carrier system (DLC) that operates on T-1 circuits. The GR-303 specification encompasses all aspects of the functionality of the DLC system. Thus, the term GR-303 is commonly used to describe a system or the framing on a set of T-1 circuits. GR-303 is used by telephone operating companies to concentrate telephone traffic and provide better maintainability. The system provides:

1. T-1 circuits exiting a switch (referred to as the IDT), and going directly to the remote digital terminal (RDT) equipment, without the need for additional equipment in the central office (CO)

2. concentration from 1:1 to 44:1.

3. a timeslot management channel (TMC) data link that uses messages for call setup and tear down.

4. the use of signalling bits to indicate call control.

5. a separate embedded operations channel (EOC) data link.

6. redundancy on the circuits that carry the data links.

7. expandability from two to 28 T-1 circuits that can carry up to 668 channels simultaneously.

8. expandability from 1 to 2048 subscriber channels.

9. ability to handle ISDN circuits (both BRI and PRI) for the subscriber.

10. multiple interface groups (IGs), so that the remote equipment can simultaneously interface to multiple switches.

The T-1 circuits are configured for ESF framing, and usually have B8ZS enabled. The first two T-1 circuits each carry the TMC and EOC for redundancy. The EOC is carried in timeslots 12 of the first and second T-1 circuits, and the TMC is carried in timeslots 24 of the first and second T-1 circuits.

According to Zarak, GR-303 has its foundation on SLC-96 mode 2. The two specifications differ in many aspects:

1. GR-303 is expandable, whereas SLC-96 is fixed at 2 T-1 circuits and 96 subscriber channels.

2. GR-303 has continual redundancy, whereas SLC-96 has an optional back up scheme.

3. the GR-303 protocols emanate directly from the switch, whereas SLC-96 requires equipment in the CO that is separate from the switch.

4. GR-303 has a comprehensive EOC which allows an operating company to do OAM&P remotely, whereas SLC-96 is limited in its capabilities.

Zarak highlights these disadvantages of GR-303:

1. The EOC is enormously complex in its implementation. This had led many manufacturers to implement a minimum number of its features, known as "EOC-light."

2. There is a combination of hybrid signalling, using messages to set up and tear down the allocation of a timeslot, and then robbed bit signalling is used to indicate the call control.

3. There is only 56 kb/s data path because of the robbed bit signalling.

4. The TMC uses messages based on ISDN and Q.931 in particular. However, because the objectives are different, the messages are not standard.

5. To add BRI, a separate channel must be allocated for the D-channel (call set up and tear down). Four BRI D-channels can be merged into one GR-303 channel, called a QDS0 (quad DS0).

6. There is no scheme to handle concentrated PRI, and a whole T-1 circuit must be permanently dedicated. www.zarak.com.