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Glossary A-C D-G H-K L-Q R-Z
H.248
The ITU standard for communication between a gateway controller and a media gateway.
H.323
An International Telecommunications Union (ITU) standard for switched multimedia communication between a LAN-based multimedia endpoint and a gatekeeper. See also gatekeeper; Session Initiated Protocol (SIP).
H0
An ISDN information transfer rate for 384-kbps data that is defined by CCITT and ANSI standards.
H11
An ISDN information transfer rate for 1536-kbps data that is defined by CCITT and ANSI standards.
H12
An ISDN information transfer rate for 1920-kbps data that is defined by CCITT and ANSI standards.
hairpinning
Rerouting the voice channel connecting two IP endpoints so that the voice channel goes through the TN2302AP IP Media Processor circuit pack in IP format instead of through the TDM bus. Communication Manager provides only shallow hairpinning, meaning that only the IP and Real Time Protocol (RTP) packet headers are changed as the voice packets go through the TN2302AP circuit pack. This requires that both endpoints use the same codec (coder/decoder), a circuit that takes a varying-voltage analog signal through a digital conversion algorithm to its digital equivalent or viceversa (digital to analog).
Half Duplex (HDX)
A circuit or device permitting data transmission in only one direction at a time between sending and receiving stations. See also duplex mode.
HDLC
High-level Data-link Control. A bit-oriented, synchronous protocol that applies to the Data-link Layer of the Open Systems Interconnection (OSI) model.
hertz (Hz)
A unit of frequency equal to one cycle per second.
HSSI
High Speed Serial Interface. A short-distance communications interface that is commonly used to interconnect routing and switching devices on Local Area Networks (LANs) with the higher-speed lines of a Wide Area Network (WAN). HSSI is used between devices that are within fifty feet of each other, and achieves data rates of up to 52 Mbps. Typically, HSSI is used to connect a router to a T-carrier system line. HSSI can be used to interconnect devices on token ring and Ethernet LANs with devices that operate at Synchronous Optical Network Optical Carrier levels (SONET OCx) speeds oron T-carrier system lines. HSSI is also used for host-to-host linking, image processing, and disaster recovery applications. Like Integrated Services Digital Network (ISDN) and Asymmetric Digital Subscriber Line (ADSL), HSSI operates at the physical layer of a network, using the standard Open Systems Interconnection (OSI) model. The electrical connection uses a 50-pin connector. The HSSI transmission technology uses differential Emitter coupled Logic (ECL) and gapped timing. Gapped timing allows a Data Communications Equipment (DCE) device to control the flow of data being transmitted from a Data Terminating Equipment (DTE) device, such as a terminal or computer, by adjusting the clock speed or deleting clock impulses. For diagnosing problems, HSSI offers four loopback tests. The first loopback tests the cable by looping the signal back after it reaches the DTE port. The second and third loopbacks test the line ports of the local DCE and the remote DTE. The fourth tests the DTE's DCE port. HSSI requires two control signals (“DTE available” and “DCE available”) before the data circuit is valid. The HSSI cable uses the same number of pins and wires as a Small Computer System Interface (SCSI-2) cable, but uses the HSSI electrical interface.
hub
A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN.
hunt group
A group of extensions that are assigned the Station Hunting feature so that a call to a busy extension is rerouted to an idle extension in the group.
Hz
See hertz (Hz).
I1
The first information channel of the Digital Communications Protocol (DCP). See also Digital Communications Protocol (DCP).
I2
The second information channel of the Digital Communications Protocol (DCP). See also Digital Communications Protocol (DCP).
ICC
See Internal Communications Controller (ICC)
ICMP
Internet Control Message Protocol. An extension to the Internet Protocol (IP). ICMP supports packets containing error, control, and informational messages.
IE
See Information Element (IE).
IEEE
See Institute of Electrical and Electronics Engineers (IEEE).
IEEE 802.3
IEEE standard for Ethernet LANs.
IETF
See Internet Engineering Task Force (IETF).
IGMP
Internet Group Multicasting Protocol, IETF STD 5: RFC 1112.
In-Band
Transmission of auxiliary information, such as management messages, using the same frequencies or channels normally used for information transfer.
Incoming Call Identifier (ICI)
A feature that is used to send the name, telephone number, or both name and telephone number of the caller over analog lines to an analog telephone set that is equipped with a display. Also called Caller ID (CID) and Incoming Caller ID (ICLID).
Information Element (IE)
The name for the data fields within an ISDN layer 3 message.
Inline error
An error which is detected by trunk firmware during normal operation and is immediately reported to switch software via an uplink inline error CCMS message.
Institute of Electrical and Electronics Engineers (IEEE)
An organization that, among other things, produces standards for Local Area Network (LAN) equipment.
Integrated Services Digital Network (ISDN)
A public or private network that provides end-to-end digital communications for all services to which users have access. An ISDN uses a limited set of standard multipurpose user-network interfaces that are defined by the CCITT. Through internationally accepted standard interfaces, an ISDN provides digital circuit-switched communications or packet-switched communications within the network. An ISDN provides links to other ISDNs to provide national digital communications and international digital communications. See also Integrated Services Digital Network Basic Rate Interface (ISDNBRI); Integrated Services Digital Network Primary Rate Interface (ISDN-PRI).
Integrated Services Digital Network Basic Rate Interface (ISDN-BRI)
The interface between a communications system and terminal includes two 64-kbps B-channels for transmitting voice or data, and one 16-kbps D-channel for transmitting associated B-channel call control and out-of-band signaling information. ISDN-BRI also includes 48 kbps for transmitting framing and D-channel contention information, for a total interface speed of 192 kbps. ISDN-BRI serves ISDN terminals and digital terminals that are fitted with ISDN terminal adapters. See also
Integrated Services Digital Network (ISDN); Integrated Services Digital Network Primary Rate Interface (ISDN-PRI).
Integrated Services Digital Network Primary Rate Interface (ISDN-PRI)
The interface between multiple communications systems that in North America includes 24 64-kbps channels that correspond to the North American Digital Signal Level-1 (DS1) standard rate of 1.544 Mbps. The most common arrangement of channels in ISDN-PRI is 23 64-kbps B-channels for transmitting voice and data, and one 64-kbps D-channel for transmitting associated B-channel call control and out-of-band signaling information. With Nonfacility-Associated Signaling (NFAS), ISDN-PRI can include 24 B-channels and no D-channel. See also Integrated Services Digital Network (ISDN); Integrated Services Digital Network Basic Rate Interface (ISDN-BRI).
Internal Communications Controller (ICC)
Also known as the Internal G350 Processor, Internal G350 Controller, or Integrated Communications Controller., it is the Pentium processor running Linux built on a media module which runs the G350 applications for call control (Avaya Call Processing), and, optionally, messaging (INTUITY), DHCP, TFTP, and HTTP. This processor is used to control G350 in its small configurations.
International Telecommunications Union (ITU)
An international organization that sets universal standards for data communications, including ISDN. ITU was formerly known as International Telegraph and Telephone Consultative Committee (CCITT).
International Telegraph and Telephone Consultative Committee
See International Telecommunications Union (ITU).
Internet
A collection of networks and gateways that use the TCP/IP suite of protocols. An internet is two or more networks connected by an internal or external router. The word “internet” is a generic term. “The Internet” is the world’s largest internet.
Internet Engineering Task Force (IETF)
One of two technical working bodies of the Internet Activities Board. The IETF develops new Transmission Control Protocol/Internet Protocol (TCP/IP) standards for the Internet.
Internet Protocol (IP)
A connectionless protocol that operates at layer 3 of the Open Systems Interconnect (OSI0 model. IP protocol is used for Internet addressing and routing packets over multiple networks to a final destination. IP protocol works in conjunction with Transmission Control Protocol (TCP), and is usually identified as TCP/IP. See also Transmission Control Protocol (TCP).
Internet Protocol Security (IPSec)
A developing standard for security at the packet processing or network layer of network communication. Earlier security approaches inserted security at the application layer of the communications model. IPSec will be especially useful for implementing virtual private networks (VPNs), and for remote user access through dial-up connection to private networks. One advantage of IPSec is that security arrangements can be handled without requiring changes to the computers of
individual users. IPSec provides two choices of security service, Authentication Header (AH) and Encapsulating Security Payload (ESP). AH allows authentication of the sender of data. ESP supports both authentication of the sender and encryption of data. The specific information that is associated with each of these services is inserted into the packet in a header that follows the IP packet header. Separate key protocols can be selected, such as the ISAKMP/Oakley protocol.
INTUITY
INTUITY describes both Avaya's flagship messaging product (hardware and software) and also the software at the heart of the G350’s messaging solution. In the context of G350, it almost always describes the software application.
in-use lamp
A red light on a multiappearance telephone that lights to show which call appearance will be selected when the handset is lifted, or which call appearance is active when a user is off-hook.
IP
See Internet Protocol (IP).
IP600
A version of Avaya Call Processing and INTUITY messaging running on an NT processor in a 4U high 19" rack mount configuration (data form factor). This configuration supports standard DEFINITY line cards and is driven by the same software as DEFINITY ONE.
IP Address
A 32-bit address assigned to hosts using TCP/IP. An IP address is written as 4 octets separated by periods (dotted decimal format). Each address consists of a network number, an optional subnetwork number, and a host number. The network and subnetwork numbers together are used for routing, while the host number is used to address an individual host within the network or subnetwork. A subnet mask is used to extract network and subnetwork information from the IP address.
IP-enabled PBX
A useful stepping-stone for customers with existing PBXs in which IP software and interfaces are added to support IP phones, softphones, and other devices.
IP Media Processor (TN2302AP)
A circuit pack that provides Voice over IP (VoIP) audio access to the switch for local stations and outside trunks. The IP Media Processor performs echo cancellation, silence suppression, fax relay service, and DTMF detection. See also Voice over IP (VoIP).
IP Server Interface (IPSI)
A circuit pack that provides for clock generation and clock synchronization, as well as tone generation and detection in S8700 Media Server configurations.
IPSec
See Internet Protocol Security (IPSec).
IPSI
IP Server Interface (DEFINITY TN 2312 Circuit Pack). Provides for clock generation and synchronization, tone generation and detection, and Port Network AA functionality.
IP telephony gateway
A device that converts an analog voice stream or a digitized version of the voice into Internet Protocol (IP) data packets.
IPX
Internetwork Packet Exchange. A network layer protocol used for transferring data from servers to workstations. IPX is primarily used in Novell NetWare operating systems.
ISDN
See Integrated Services Digital Network (ISDN).
ISDN-BRI
See Integrated Services Digital Network Basic Rate Interface (ISDN-BRI).
ISDN facility
See ISDN trunk.
ISDN Gateway (IG)
A feature that uses a link to a gateway adjunct to integrate the switch and a host-based telemarketing application. The gateway adjunct is a 3B-based product that notifies the host-based telemarketing application of call events.
ISDN-PRI
See Integrated Services Digital Network Primary Rate Interface (ISDN-PRI).
ISDN trunk
A trunk that is administered for use with ISDN-PRI. Also called an ISDN facility.
ISDN-PRI terminal adapter
An interface between endpoint applications and an ISDN-PRI facility. ISDN-PRI terminal adapters are currently available from other vendors and are primarily designed for video conferencing applications. Accordingly, currently available terminal adapters adapt the two pairs of video codec data (V.35) and dialing (RS-366) ports to an ISDN-PRI facility.
ISO
International Standards Organization.
IT
Information Technology. A term that encompasses all forms of technology used to create, store, exchange, and use information in its various forms (business data, voice conversations, still images, motion pictures, multimedia presentations, and other forms, including those not yet conceived). IT is a convenient term for including both telephony and computer technology in the same word. It is the technology that is driving what has often been called “the information revolution.”
ITU
See International Telecommunications Union (ITU).
IVR (interactive voice response)
An automated telephone answering system that plays voice prompts or voice menus and allows the user to respond via the telephone keypad. IVR systems may also use speech recognition to enable spoken input, and may integrate database access and/or fax response.
IXC
Interexchange Carrier.
jabber
An error condition in which a network device continually transmits random, meaningless data onto the network. In IEEE 802.3, jabber refers to a data packet, the length of which exceeds the maximum length prescribed in the standard.
kbps
Kilobits per second.
kbyte
Kilobyte.
kg
Kilogram.
kHz
Kilohertz.
A-C D-G H-K L-Q R-Z
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