AddPac IPNext190 Installation Manual page 126

IPNext 190 System Installation Guide
G.726
G.728
Gatekeeper
H.225
H.245
H.323
HBD3
HDLC
Hookflash
This standard specifies ADPCM coding performed at a rate of 40Kbps, 32Kbps, 24Kbps, or
16Kbps. If the PBX network is configured to support ADPCM, you can exchange ADPCM
encoding voice with packet voice networks, PSTN, or PBX networks. This standard is
specified under the ITU-T standard of G-series recommendation.
This standard specifies variations that ensure low delay of CELP voice compression
performed at 16Kbps. The CELP voice coding should be converted to a public telephony
format for transmission over either PSTN or PSTN. This standard is specified under the
ITU-T standard of G-series recommendation, and defines the CELP compression that
encodes G.729 voice to a stream of 8Kbps. G.728 has two variations (G.729 and G.729
Annex A), and the variations are different in terms of calculation complexity. The two
variations have voice quality similar to ADPCM of 32Kbps. G.728 is specified under the
ITU-T standard of G-series recommendation.
This is the component of the H.323 video conference system that analyzes a caller ID,
controls access authorization, and manages the subnet bandwidth. A gatekeeper is H.323
entity that provides the features that enable address conversion and LAN access control to
the H.323 terminal and gateway on LAN. Gatekeepers can provide other services such as
bandwidth control and search for a gateway to the H.323 terminal and gateway. This device
manages a device registry on a multimedia network. The devices are registered with the
gatekeeper, and they request the gatekeeper to authorize a call.
This ITU standard is applied to the session setting and packetization of H.225.0. H.225.0
specifies a variety of protocols such as RAS, Q.931, and RTP.
This ITU standard is applied to H.245 endpoints control.
This standard is an extension of the ITU-T standard H.320 that enables voice conferences
over LAN or another packet switching network as well as video transmission over the
Internet.
This is a type of line codes used for E1.
Stands for High-Level Data Link Control. HDLC is a transmission protocol used in the data
link layer, which is the second layer of the 7-layer OSI model. HDLC is used in the X.25
packet switching network. Data consists of frames in HDLC, and frames are transmitted
through a network. The destination verifies if the frames have been successfully
transmitted. The HDLC protocol includes data for controlling data flow and
troubleshooting errors in a data frame.
This is a short on-hook duration of a device such as phones during a call. Hookflash means
that a phone attempts to make a dial tone recall through PBX. This is usually used to
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