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Glossary
110
December, 2005 Vodavi Telenium IP Product Guide
mobility ▪ presence ▪ collaboration ▪ convergence
Gigabit
Ethernet Gigabit Ethernet, a transmission technology based on the Ethernet frame format and protocol
used in local area networks (LANs), provides a data rate of 1 billion bits per second (one gigabit).
GSM Global System for Mobile Communications
H.225 H.225 is an ITU standard protocol for controlling signaling in an H.323 environment.
H.245 H.245 is a protocol that is used to manage and control various aspects of call setup and
connection. On an H.323 call.
H.248 This is the ITU-T recommendation for MGCP (Media Gateway Control Protocol), which is an open,
standards-based signaling and control protocol for use between circuit switched PSTNs (Public
Switched Telephone Networks) and VoIP (Voice Over Internet Protocol) networks.
H.323 An ITU-T standard which serves as the umbrella for a set of protocols defining real-time voice and
video communications for packet-based networks. The standards under the H.323 umbrella
define how components that are built in compliance with H.323 can set up calls, exchange
compressed audio and/or video, participate in conferences, and interoperate with non-H.323
endpoints.
H.450 An ITU-T standard which defines supplementary services for packet-based (H.323) networks.
H.450 is similar to QSIG, which defines supplementary services for ISDN networks.
Half Duplex Half-duplex data transmission means that data can be transmitted in both directions on a signal
carrier, but not at the same time. For example, on a local area network using a technology that
has half-duplex transmission, one workstation can send data on the line and then immediately
receive data on the line from the same direction in which data was just transmitted. Like full-
duplex transmission, half-duplex transmission implies a bidirectional line (one that can carry data
in both directions).
Host A computer system or device connected to a network.
Hot Spot A WLAN node that provides a wireless Ethernet connection from a given location. Increasingly,
public places, are offering hot spots to provide free wireless access for customers.
Hot Zone A wireless access area created by multiple hot spots located in close proximity to each other. Hot
zones usually combine public safety access points with public hot spots. Each hot spot typically
provides network access for distances between 100 and 300 feet; various technologies, such as
mesh network topologies and fiber optic backbones, are used in conjunction with the hot spots to
create areas of coverage.
HTTP HTTP (Hypertext Transfer Protocol) is the set of rules for transferring files (text, graphic images,
sound, video, and other multimedia files) on the World Wide Web. HTTP is an application protocol
that runs on top of the TCP/IP suite of protocols (the foundation protocols for the Internet).
Hub The point on a network where circuits are connected. In LANs, a hub is the core of a physical star
configuration. Hubs, as a physical device, aren’t switches, as they have very little intelligence, and
don’t set up transmission paths. Instead, hubs comprise a physical bus and a group of ports, to
which are connected patch cables, to which are connected individual terminal devices. Unlike
switches, hubs do nothing internal to prevent or control congestion.
ICMP ICMP (Internet Control Message Protocol) is a message control and error-reporting protocol
between a host server and a gateway to the Internet.
IEEE Institute of Electrical and Electronics Engineers, usually known as 'eye triple e.' A global standards-
setting body comprised of engineering professionals.
IETF Internet Engineering Task Force. Formed in 1986 when the Internet was evolving from a Defense
Department experiment into an academic network, the IETF is one of two technical working
bodies of the Internet Activities Board. The IETF sets the technical standards that run the
Internet.
Internet The global network of computers with publicly-reachable addresses.
Intranet An intranet is a private network that is contained within an enterprise. It may consist of many
interlinked local area networks and also use leased lines in a wide area network.