RADVISION术语表

Glossary (G)

# - A - B - C - D - E - F - G - H - I - J - K - L - M - N
O- P - Q - R - S - T - U - V - W - X - Y - Z

G.711
An ITU-T standard for speech codecs that provides toll quality audio at 64 Kbps using the PCM method and either μμ-law or A-law.

G.722
An ITU-T standard for speech codes that provides toll quality audio at 64 Kbps.

G.722.1
An ITU-T standard for speech codecs that compresses 50Hz - 7KHz audio signals into one of two bit rates, 24 or 32 Kbps.

G.723.1
An ITU-T standard for speech codecs that provides good quality audio at 5.3 or 6.3 Kbps.

G.726
An ITU-T ADPCM speech codec standard covering the transmission of voice at rates of 16, 24, 32, and 40 Kbps. G.726 also introduced a new 16 Kbps. The four bit rates associated with G.726 are often referred to by the bit size of a sample, which are 2-bits, 3-bits, 4-bits, and 5-bits respectively.

G.728
An ITU-T standard for speech codecs that provides near-toll quality audio at 16 Kbps.

G.729 A/B
An ITU-T standard for speech codecs that provides near-toll quality audio at 8 Kbps. G.729 Annex A is a reduced complexity codec and G.729 Annex B supports silence suppression and comfort noise generation.

GAN (GENERIC ACCESS NETWORK)
Formerly known as Unlicensed Mobile Access (UMA), describes a telecommunication system allowing seamless roaming and handover between local area networks and wide area networks using the same dual-mode mobile phone.

GATEKEEPER
In H.323 IP telephony, a Gatekeeper is an optional server that is responsible for network-based services including registration, admission and status, for which it uses a special protocol called RAS. Gatekeeper functions include address translation, call authorization and bandwidth management, as well as providing accounting information.

GATEKEEPER ZONE
A group of endpoints together with their Gatekeeper constitute a zone. You can configure a zone by predefining endpoints that are entitled to register with the Gatekeeper.
See also Predefined Endpoint, Registered Endpoint, Zone

GATEWAY
A Gateway is a network entity, which provides a bridge between networks. An H.323 Gateway provides real-time, two-way communication between H.320 terminals on the packet-based network and other ITU terminals on a circuit switching network, or to other H.320 Gateways. A video Gateway provides real- time, two-way multimedia communication between video terminals on different networks. For example, between H.323 terminals on a packet-based network and H.320 terminals on an ISDN network, or between H.323 terminals on a packet-based network and 3G-324M. terminals on a 3G mobile network

GATEWAY SUPPORTED PREFIXES
H.323 version 2 enables a Gateway to specify prefixes that the user should dial before the WAN number in order to make a call using a certain media.

GCF (GLOBAL CERTIFICATION FORUM)
A partnership between network operators and terminal manufacturers that provides an independent program to ensure global interoperability of 2G and 3G mobile wireless terminals whose objective is to boost industry confidence in the performance and reliability of new 3G mobile devices.

GERAN (GSM/EDGE RADIO ACCESS NETWORK)
The interface between the EDGE radio network and the core network. Also defining an interface between two BSS.

GPRS (GENERAL PACKET RADIO SERVICE)
A mobile data service available to users of GSM mobile phones. It is often described as "2.5G" - or a technology that is between the second (2G) and third (3G) generations of mobile telephony.

GROUP HUNTING
Group Hunting enables a Gatekeeper to perform load balancing for a group of H.323 endpoints defined with the same alias.

GSM (GLOBAL SYSTEM FOR MOBILE COMMUNICATIONS)
The standard digital cellular phone service of Europe, Japan, Australia and elsewhere.