G.729, Group id, H.323 – Comtech EF Data Vipersat Circuit Scheduler v3.7.x ArrangeLink User Manual
Page 80: Hdlc, Http, Icmp

A-4
ArrangeLink User Guide
FTP File Transfer Protocol – An application for transferring computer files over the
Internet. See also TFTP.
G
G.729 ITU standard for LD-CELP (Low Delay – Code Excited Linear Prediction)
voice encoding at 8 kb/s.
GIR Guaranteed Information Rate
Group ID A number assigned to equipment which defines it as a member of a group when
addressed by the VMS burst controller.
GUI Graphical User Interface – A form of graphical shell or user interface to a
computer operating system or software application.
H
H.323 A protocol standard for multimedia communications designed to support real-
time transfer of audio (such as voice over IP) and video data over packet
networks. Quality of Service is a key feature of H.323. An alternative to SIP.
HDLC High Level Data Link Control – A standard defining how data may be transmit-
ted down a synchronous serial link.
HPA High Power Amplifier – The amplifier used in satellite communications to raise
the transmit signal to the correct power level prior to transmission to satellite.
HTTP Hyper Text Transfer Protocol – The Internet standard for World Wide Web
(WWW) operation.
Hub The central site of a network which links to a number of satellite earth sites
(remotes).
I
ICMP Internet Control Message Protocol
IDU Indoor Unit – In a VSAT system, the satellite modem is referred to as the IDU.