Generic term used to describe a cabinet s containing the memory, processors, circuitry, and equipment necessary to support a group of stations. Network facility with bandwidth of A protocol developed to allow dissimilar devices to communicate across many kinds of networks.
Individual channels or circuits that can be grouped. This is the smallest denominator for a network facility. Specialized connections between a remote module s and the main host in the 5ESS switch.
Similar to a SNI facility, these carry control information. System that specifically supports the voice mail application and is connected to the telephone switch. Calls are passed between the two systems, which communicate with each other to light the light on your telephone when you have a message. Voice over IP. A technique that allows voice to be carried in a portion of the bandwidth of an Ethernet signal that is carrying IP traffic. Analog Line Phone line using an analog wave form for transmission of speech.
ANI Automatic number identification. Automated Attendant Voicemail-based menu tree that helps direct callers to appropriate information or destinations. Blue Lights Slang; see Emergency Phones. CSU Channel service unit. Used to terminate a T1 facility.
DS0 Network facility with bandwidth of up to 64kb. DS1 Network facility with bandwidth of 1. DS3 Network facility with bandwidth of 45 MB, sometimes channelized to provide multiple T1 facilities. DTMF Dual-tone multi-frequency standard signaling used for touch-tone dialing. E Phone Slang. See Emergency Phones.
Elevator Phones Phones on the same system as Emergency Phones. Ethernet Local area network used for connection computers, printers, workstations, or terminals. IP Internet Protocol. Loop Start Way of signaling initiation of a call by creating a loop across the two wires of a telephone pair.
PDN alt. SDN alt. Software Defined Network. A virtual private network. Sonet Synchronous Optical Network Stations In the voice world, a station is any terminal equipment that utilizes a port on the switch. Satellites are used to transmit telephone, television and data signals originated by common carriers, broadcasters and distributors of cable TV program material. SHVIA also permits satellite companies to provide "distant" network broadcast stations to eligible satellite subscribers.
A service plan typically consists of a monthly base rate for access to the system and a fixed amount of minutes per month. Such unauthorized switching violates FCC rules. These wires, poles and other facilities are referred to as the "local loop. TTY A type of machine that allows people with hearing or speech disabilities to communicate over the phone using a keyboard and a viewing screen. It is sometimes called a TDD.
UNIVERSAL SERVICE The financial mechanism which helps compensate telephone companies or other communications entities for providing access to telecommunications services at reasonable and affordable rates throughout the country, including rural, insular and high costs areas, and to public institutions.
Companies, not consumers, are required by law to contribute to this fund. The law does not prohibit companies from passing this charge on to customers. Wireline Competition. Tuesday, January 28, Digital Media Refers to any type of information in digital format including computer-generated text, graphics and animations, as well as photographs, animation, sound and video.
See also Call Setup routing. Directional Microphone A microphone that detects and transmits sound from only a certain direction. Useful in preventing unwanted sound from being transmitted.
Display The visual presentation on the indicating device of an instrument. Distance Learning Incorporation of video and audio technologies so that students can "attend" classes and training sessions presented at a remote location. Document Sharing A videoconferencing feature that enables multiple participants to view and edit the same computer document. Double-Talk The situation where parties at both ends of a conference are speaking simultaneously. A quality echo canceller will provide a continuous speech path I-directionally during double-talk.
Downspeeding The ability of a Gateway to maintain a ISDN video call by reconnecting the call at a lower rate when one of the B channels is lost.
Downspeeding contributes to a higher percentage of call completion on the network. A worldwide standard for digitizing one voice conversation and more recently for data transmission. A telephony term describing a 1. The tones that are heard when you press the buttons on a touch-tone telephone.
The videoconferencing equipment performs a two channel inverse multiplexing procedure to assure channel alignment. PLV is a proprietary compression technique that is well suited for encoding full motion.
Dynamic Bandwidth Allocation The process of determining current traffic loads over a channel and automatically increasing or decreasing the bandwidth of the channel to optimize the utilization of bandwidth efficiency. E-box Electronics box the main codec box of a group videoconferencing system.
Echo Canceller Eliminates audio transmission echo. A telephone line echo canceller produces a synthetic replica of the echo it expects to see returning and subtracts it from the transmitted speech.
The replica it creates is based on the transmission characteristics of the telephone cable between echo canceller and the telephone or videoconferencing system. Device that allows for the isolation and filtering of unwanted signal caused by echoes from the main transmitted signal.
Echo Effect A time-delayed electronic reflection of a speaker's voice. This is largely eliminated by modern digital echo cancellation. Echo Suppression A technique for reducing annoying echoes in the audio portion of a videoconference by temporarily deadening the communication link in one direction.
Electronic Blackboard A device or whiteboard that looks like an ordinary blackboard or whiteboard, but has a special conductive surface for producing free hand information that can be sent over telephone lines. Endpoint A network element at the end of the network such as an H.
A France-based non-profit making organization that produces telecommunications standards to be used throughout Europe and beyond. Exit Zone When you define a prefix for the Exit Zone Service, you need to dial the prefix to reach an endpoint in another zone. This can be useful for restricting unauthorized users from making calls to other zones.
The Exit Zone prefix affects the way in which the Gatekeeper tries to complete calls to other zones. Fallback A modem speed that is lower than its normal that is, maximum speed of operation.
A procedure for shortening the time it takes to start a call by skipping the H. An independent US government agency charged with regulating interstate and international communications by radio, television, satellite and cable. Fiber Optics A communications medium utilizing laser or "light" transmission. Uses a glass or plastic fiber carrying light to transmit voice, data and video signals.
Field One half of a video frame. One field contains all of the odd or all of the even scanning lines of the picture. Firewall A barrier device placed between two separate networks. A firewall can be implemented in a single router that filters out unwanted packets or it can use a variety of technologies in a combination of routers and hosts. Flow Control Comprised of the hardware, software and procedure for controlling the transfer of IP packets between two points on a network.
Four-wire Circuit A circuit that uses two pair of conductors four wires , one pair to transmit the signals and one pair to receive; allows two parties to communicate simultaneously.
Frame Full screen or frame of video made up of two fields. Thirty frames is one second of video. Frame Rate The rate at which individual pictures frames in a sequence are displayed in a video conference.
Frame rate is measured in frames per second fps. Frame Relay Method for sending high-bandwidth data in frames not video frames, but "blocks" of data.
Uses packet switching, not circuit switching. Full-duplex audio Two-way audio may be captured and reproduced simultaneously. With full-duplex audio, the microphone may capture local audio for transmission while the far end audio may be heard clearly. Interruptions and double-talk are possible. Full-motion Video Not compressed. A standard video signal of thirty frames per second fps , horizontal lines per frame, capable of complete action.
Much less long-term fatigue from user when wide-band audio is used. Gatekeeper In H. 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 network element that performs conversions between different coding and transmission formats. See Bridge. Gateway Redundancy The Gateway Redundancy feature enables the Gatekeeper to request that other Gatekeepers search their zones to locate a request when Line Hunting fails to find a suitable service provider.
If no service is found, the Gateway Redundancy policy enables the Gatekeeper to complete the call by referring the call to other Gatekeepers. Gateway Supported Prefixes H. GOB Groups of Blocks. In the encoding process, each picture is subdivided into groups of blocks and then further divided into macro blocks. HMLP High-speed multi-layer protocol.
Standard for high-speed transmission. The basis of the security process is the shared secret between the endpoint and the Gatekeeper. The H. The endpoint must also support H. Is also an optional mode of the other H-series standards. HDTV is generally defined as a system that offers double the horizontal and vertical resolution compared to existing systems and provides compact disc quality sound. Dynamically eliminates conference echo so that true full-duplex audio is possible.
Industry forum for promoting interoperability trials. Device that bonds two or more BRI lines to form a higher rate channel. In-band signaling Signaling made up of defined bits which pass within the data transmission stream. Instant Messaging IM A communications service that enables you to create a private chat room with another individual in order to communicate in real time over the Internet.
Inverse Multiplexing The creation of a single higher speed data channel by combining and synchronizing two or more lower speed data channels. IP Internet Protocol. Packet-based protocol for delivering data across networks.
IP addresses are 32 bits long. Each octet is represented in decimal and is separated by dots. IP multicast is used for streaming audio and video over the network. A set of standards that provide a common architecture for the development and deployment of digitally integrated communications services.
International standards body concerned with non-telecommunications issues. Organization composed of the telecommunications administrations of the participating nations.
Focus is the maintenance and extension of international cooperation for improving telecommunications development and applications. Responsible for all international telecommunications standards. ITAs include TV answer, a two-way television service for consumers for game shows, sporting events and respond instantly to new polls, interactive advertising as well as distance learning. The system will allow viewers to shop, bank, pay bills and order a pizza.
Jitter The result of a change in latency or the tendency towards lack of synchronization caused by mechanical or electrical changes. Technically, jitter is the phase shift of digital pulses over a transmission medium. Jitter Buffer A portion of memory specifically allocated to storing IP packets awaiting transmission, or to storing received IP packets. The buffer facilitates flow control by capturing IP packets and then transmitting packets as "playback" using speeds and rates of delay that the destination device can handle without causing packet loss through overloading.
Jitter Buffer Management Jitter buffer management represents the trade-off between a larger buffer and increased rates of jitter. JPEG is an industry standard for still image compression that has moved into full motion video. JPEG is a compression technique based upon intraframe encoding technology. It allows for the full restoration of symmetrically compressed images. Kbps Kilobits per second. A unit of measure of data of 1, bits per second.
A private transmission network interconnecting offices within a building or a group of buildings used to convey voice, data and video traffic. Latency A measure of accumulated waiting time or delay, representing the length of time required for information to pass through a network. Lavaliere A small microphone that can be clipped onto clothing or suspended from neck cords and worn in front of the chest.
LDAP is both an information model and a protocol for querying and manipulating the model. Leased Lines A term used to describe the leased or rented use of dedicated lines between two points.
Carriers that can carry only intra-LATA traffic. A display technology that uses a semiconductor diode that emits light when charged. LEDs usually indicate both correct and problematic operation. Line Hunting A Gateway supports a list of prefixes services. Gateway unavailability to receive a call means that the Gateway cannot accept calls with the particular prefix in question.
The Line Hunting function of a Gatekeeper searches for a Gateway which is free to accept calls with this prefix. Load Balancing The practice of splitting communication into two or more routes. By balancing the traffic on each route, communication is made faster and more reliable. Master The side in communications which initiates and controls the session.
The "slave" is the other side that responds to the master's commands. Mbps Megabits per second. A unit of measure of data of 1,, bits per second. See Bridge 2. MLP Multi-layer protocol for data in H. Multimedia compression standard for professional and consumer applications such as digital video, digital audio and systems compression.
MPEG compresses similar frames of video, tracks elements which change between frames and discards the redundant information. MPEG is a series of standards designed to reduce the storage requirements of digital video. MPEG-4 provides the standardized technological elements for the integration of interactive graphics applications and interactive multimedia. Multiplexing The process of combining a number of individual channels into a common frequency band or into a common bit stream for transmission.
The converse equipment or process for separating a multiplexed stream into individual channels is called a demultiplexer.
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