ABBREVIATION DICTIONARY Networks and Telecommunications/Electronics --> G

G

GGP
Gateway-to-Gateway Protocol







GHz
Gigahertz







GIF
Graphics interchange format. A common format for image files on the World Wide Web; suitable for images containing large areas of the same color. See also JPG and TIFF.







GPS
Global Positioning Satellite







GRE
Generic Routing Encapsulation







GSM
Global System for Mobile Communications: the European standard for digital cellular service using slow frequency-hopping and TDMA.







GUI
Pronounced "gooey." Graphical user interface. A software interface based on pictorial representations and menus of operations and files. Opposite of command line interface







GX 550 Switch
A carrier-class asynchronous transfer mode (ATM) core switch that delivers OC48/STM-16 capacity. The GX 550 combines the capacity and scalability of a core switch with the service capabilities of an edge switch, providing backbone transport and user services on a single platform.







Gallium Arsenide (GaAs)
A compound semiconductor material used for making electronic devices such as lasers and light-emitting diodes. It radiates light when an electric current is passed through it. Because of their electron structure, GaAs devices are faster than those of silicon.







Gate Array
A chip consisting of an arrangement of gates that can be connected during the production process to perform tasks specified by the customer.







Gated
A program than runs under 4.3 BSD UNIX on a gateway to allow gateway to collect information from within one autonomous system using RIP, HELLO or other interior gateway protocols, and to advertise routes to another autonomous system using the Exterior Gateway Protocol (EGP).







Gatekeeper
A device that manages an IP network, supporting all gateways, user profiles, and authentication. A gatekeeper is defined by the H.323 standard.







Gateway
Gateways are points of entrance to and exit from a communications network. Viewed as a physical entity, a gateway is that node that translates between two otherwise incompatible networks or network segments. Gateways perform code and protocol conversion to facilitate traffic between data highways of differing architecture. In OSI terms, a gateway is a device that provides mapping at all seven layers of the OSI model. A gateway can be thought of as a function within a system that enables communications with the outside world.







Generic Filters
When creating filters, you can specify the Type of filter as Generic or IP. Generic filters define bits and bytes within a packet and can apply to any packet type, including TCP or IP. (IP filters relate to the TCP/IP/UDP protocol suite only.)







Ghz
Abbreviation for Gigahertz, or 1 billion hertz. Giga is the Greek prefix meaning a billion.







Gigabit
One thousand million bits







Gigabits (Gbps)
An acronym meaning gigabits (one billion bits) per second, and a measure of the capacity of a device.







Gigahertz
Hz x 10(9)







Gigahertz (GHz)
GHz is a unit of wave frequency equal to one billion hertz (1,000,000,000 Hz). In some computers, microprocessor clock speed is measured in GHz. Personal computer clock speeds are generally a few tenths of a GHz, but are increasing toward 1 GHz.







Glare
A signal the switch sends when you attempt to place an outgoing call and answer an incoming call simultaneously.







GloBanD
A European Switched Nx64 data service consisting of a single circuit whose bandwidth is a multiple of 64 kbps. This circuit consists of one or more B channels. For example, if a caller requests 512 kbps service, the line uses 8 B channels to supply the requested bandwidth. This service is available over T1 PRI lines only, and follows the CCITT Q.931 recommendation. It differs from MultiRate in being an overlay network, rather than an integral part of the worldwide switched digital infrastructure.







Global Positioning Systems
A system that uses radio signals between a vessel or vehicle on Earth to pinpoint the location of the vehicle or vessel.







Global System for Mobile Communications (GSM)
The European standard for digital cellular service that includes a suite of enhanced features similar to ISDN.







Globally Significant DLCI
In frame relay, a feature that enables DLCIs to use the same connection-identification scheme across the network for the purpose of specifying individual end devices. This functionality is part of the link management interface (LMI) enhancement to frame relay.







Graded-index Fiber
A type of fiber in which the refractive index starts at a high value in the center of the core and decreases smoothly toward the protective covering, or cladding.







Grooming
In telecommunications, the process of separating and segregating channels, as by combing, such that the broadest channel possible can be assembled and sent across the longest practical link. The aim is to minimize de-multiplexing traffic and reshuffling it electrically.







Ground-start Signaling
A signaling method in which the customer premises equipment (CPE) transmits an off-hook condition by creating a zero-voltage condition.







Group Address
An address that allows a switched multimegabit data service (SMDS) data unit to be delivered to multiple Subscriber Network Interfaces (SNIs).







Guaranteed Packets
Data delivered with high reliability within a specified time constraint.