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EXFO Glossary

G (browse from .......... to)
G.992.1 or G.DMT ADSL...............GigEGIS...............GUI
G.992.2 or G.Lite ADSLGEMGFP-T
G.fastGeneral Communication Channel (GCC)Giants
G_PortGeneralized Multiprotocol Label Switching (GMPLS)Gigabit Ethernet (GigE)
GatewayGeneric Framing Procedure (GFP)Gigabyte (GB)
Gbit/s or Gb/s or GbpsGeographic Information System (GIS) GigE
from G.992.1 or G.DMT ADSL... to GigE

G.992.1 or G.DMT ADSL

A kind of asymmetric DSL technology, based on DMT modulation, that offers a downstream bandwidth of up to 8 Mbit/s, and an upstream bandwidth of up to 1.544 Mbit/s. G.DMT is another name for the standard officially known as ITU-T Recommendation G.992.1.

G.992.2 or G.Lite ADSL

A kind of asymmetric DSL technology, based on DMT modulation, that offers maximum Internet connectivity rates up to 1.5 Mbit/s downstream and 384 kbit/s upstream. G.Lite is another name for the standard officially known as ITU-T Recommendation G.992.2.

New DSL technology to allow Gbit/s transmissions on copper twister pairs.


Acronym for: Generic port


A physical or logical point of entrance to another network. A router, computer, server or an integrated access device can serve as a gateway to a network.

Gbit/s or Gb/s or Gbps

Gigabits per second. One Gbit/s equals one billion bits per second.


Acronym for: Guaranteed bit rate


Acronym for: GPON encapsulation mode

General Communication Channel (GCC)

Defined by G.709, is an in-band side channel used to carry transmission management and signaling information within optical transport network elements.

Generalized Multiprotocol Label Switching (GMPLS)

A protocol suite extending MPLS to manage further classes of interfaces and switching technologies other than packet interfaces and switching, such as time division multiplex, layer-2 switch, wavelength switch and fiber-switch.

Generic Framing Procedure (GFP)

Traffic adaptation protocol providing convergence between packet-switched and transmission networks. GFP elegantly maps packet-based protocols such as Ethernet, Fibre Channel, FICON, ESCON and various forms of digital video into SONET/SDH, typically using virtual concatenation to provide right-sized pipes for data services.

Geographic Information System (GIS)

A system designed to capture, store, manipulate, analyze, manage, and present all types of geographical data.


Acronym for: Generic Framing Procedure - Framed


Acronym for: Generic Framing Procedure - Transparent


Giants are frames that are longer than the maximum Ethernet size (giant frames > 1518/1522 bytes with bad FCS, whereas oversize frames > 1518/1522 bytes with good FCS). Giant packets usually occur when you have a jabbering node on your network; i.e., a node that is continuously transmitting, or transmitting improperly for short bursts—probably due to a bad transmitter on the NIC. Giants can also be caused by packets being corrupted as they are transmitted, either by the addition of garbage signals, or by the corruption of the bits that indicate frame size.

Gigabit Ethernet (GigE)

A version of Ethernet that operates at 1 Gbit/s (1000 Mbit/s).

Gigabyte (GB)

1,000,000,000 bytes, or 1,000 megabytes (see Byte).


Acronym for: Gigabit Ethernet (operates at 1 Gbit/s; i.e., 1000 Mbit/s)