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Glossary A-C D-G H-K L-Q R-Z
L2TP
See Layer 2 Tunneling Protocol (L2TP).
LAG
Link Aggregation Groups provide a method for creating a high-bandwidth link. A LAG, also known as a hunt group, consists of a group of ports acting as a single logical port. All participating ports must have the same configuration. See also hunt group.
LAN
See Local Area Network (LAN).
layer 2 switch
An IP component that statically reroutes packets and streams to another port on the layer 2 switch based on the destination Media Access Control (MAC) address.
Layer 2 Tunneling Protocol (L2TP)
A standard for layer 2 tunneling for remote access, established by the Internet Engineering Task Force (IETF).
leaky bucket
This is the process of setting a threshold, and depending upon the inflow rate of errors versus the outflow (the leaking out over time), set or remove a status, typically an alarm. In other words, if errors are coming faster than the leak out, a threshold will be reached and an alarm is set. If, over time, the inflow rate of errors is less then the outflow (removal of the error over time), the alarm is removed.
Light-Emitting Diode (LED)
A semiconductor device that produces light when voltage is applied. LEDs provide a visual indication of the operational status of hardware components, the results of maintenance tests, the alarm status of circuit packs, and the activation of telephone features.
line
A transmission path between a communications system or a Central Office (CO) and a telephone or other terminal.
Link Access Procedure-d (LAPD)
A link-layer protocol on the ISDN-BRI data-link layer (level 2) and the ISDN-PRI data-link layer (level 2). LAPD provides data transfer between two devices, and error and flow control on multiple logical links. LAPD is used for signaling and low-speed packet data (X.25 and mode 3) on the signaling (D) channel, and mode 3 data communications on a Bearer (B) channel. Also called Link Level Protocol for the D-Channel.
Linux
One operating system that runs DEFINITY® as an application.
little endian
A format of storage or transmission of binary data in which the least-significant byte comes first.
Local Area Network (LAN)
A networking arrangement that is designed for a limited geographical area. Generally, a LAN is limited in range to a maximum of 6.2 miles, and provides high-speed carrier service with low errorrates. Common configurations include daisy chain, star (including circuit-switched), ring, and bus.
Local Exchange Carrier (LEC)
A local telephone company.
Local Survivable Processor (LSP)
A configuration of the S8300 Media Server that is used to provide redundancy in Avaya Communication Manager. In the LSP configuration, the server acts as an alternate server or gatekeeper for IP entities such as IP telephones and Avaya G700 Media Gateways. These IP entities use the LSP when the entities lose connectivity to the primary server. Also called survivable cc.
logical link
The communications path between a processor and a Basic Rate Interface (BRI) terminal.
MAC
See Media Access Control (MAC).
MAC address
Media Access Control Address. The MAC Address is a hardware address that uniquely identifies each node of a network.
MAC layer
In IEEE 802 networks, the MAC layer is a sublayer of the Data Link Control (DLC) layer. The MAC layer interfaces directly with the network media. Each different type of network media therefore requires a different MAC layer.
MAC list
A list of MAC addresses of devices that are allowed to access the network through the selected port. Each port can have a MAC list. If the port's security option is enabled, no device can access the port unless the device's address is on the port's MAC list.
maintenance
Activities to keep a telecommunications system in proper working condition. Maintenance activities include the detection and isolation of software and hardware faults, as well as automatic and manual recovery from these faults.
major alarm
An indication of a failure that caused critical degradation of service, and that requires immediate attention. Major alarms are automatically displayed on LEDs on maintenance or alarming circuit packs and the attendant console. Major alarms are then logged to the alarm log and reported to a remote maintenance facility, if applicable.
MAN
Metropolitan Area Network. A data communications network designed for a town or city, usually characterized by high-speed connections using fiber optical cable or other digital media.
Mbps
Megabits per second.
Mbyte
Megabyte.
Media Access Control (MAC)
A general reference to the low-level hardware protocols that are used to access a particular network. The term MAC address is often used as a synonym for physical address.
Media Gateways
Distributed systems that connect IP communications to traditional communications, including phones and the public switched telephone network (PSTN). Some vendors combine gateways with networking equipment, and some, like Avaya, allow gateways to re-use existing telephony investments. See also Avaya Media Gateway.
Media Gateway Control Protocol (MGCP)
A protocol that gatekeepers use to control gateways. In the Internet Engineering Task Force (IETF), MGCP was superseded by the Megaco protocol, which was unified with the ITU H.248 standard of the ITU (formerly H.gcp). See also gatekeeper.
Media Gateway Controller (MGC)
Controls the parts of the call state that pertain to connection control for media channels in an MG. This is the controlling entity in an H.248 relationship.
media module
In the G350, this refers to a removable, hot-pluggable circuit pack that can be inserted into one of the slots on the chassis.
media module slots
Four positions in the Avaya G700 Media Gateway that contain various telephony interface circuits oran integrated Avaya S8300 Media Server. Each slot has access to one of the eight L2 switch ports, the TDM bus, and various control signals from the gateway server. The media module slots support hot board swap.
Media processing
Sending and receiving information from any communications medium, such as faxes, voice conversations or data.
media server
See Avaya Media Server.
message center
An answering service that supplies agents to take messages, and stores messages for later retrieval.
message center agent
A member of a message center hunt group who takes and retrieves messages for telephone users.
Message Waiting Lamp (MWL)
A light on a telephone that indicates the presence of a message for the telephone user.
MGCP
See Media Gateway Control Protocol (MGCP).
MGP
Media Gateway Processor.
MIB
Management Information Base. A database of network management information that can be monitored by a Network Management System. Both SNMP and RMON use standardized MIB formats that enable any SNMP and RMON tool to monitor any device defined by an MIB.
minor alarm
An indication of a failure that could affect customer service. Minor alarms are automatically displayed on LEDs on maintenance or alarming circuit packs and the attendant console. Minor alarms are then sent to the alarm log, and reported to a remote maintenance facility, if applicable.
modem
A device that converts digital data signals to analog signals for transmission over telephone circuits. The analog signals are converted back to the original digital data signals by another modem at the other end of the circuit.
module
A self-contained communications unit that may be used in combination with other units. Examples include individual Avaya P330 units and cards that slot into the Avaya P580/P882 device.
ms
Millisecond.
multiappearance telephone
A telephone equipped with several call appearance buttons for the same extension, enabling the user to handle more than one call on that extension at the same time.
Multifrequency Compelled Release 2 (MFC R2) signaling
A method of signaling in which a signal consists of two frequency components. With MFC R2 signaling, a switch that transmits a signal receives a second signal that acknowledges the transmitted signal. MFC R2 signaling is used in the US and other countries.
Multimedia routing
Routing voice, data andInternet calls (audio, video, both) within a contact center.
Multipoint Control Unit (MCU)
A bridging or switching device that is used to support multipoint video conferencing. An MCU can support 28 conference sites.
MWI
Message Waiting Indicator. See Message Waiting Lamp (MWL).
N x DS0
An emerging standard for wideband calls separate from H0, H11, and H12 ISDN channels. The N x DS0 ISDN multirate circuit mode bearer service provides circuit-switched calls with data-rate multiples of 64 kbps up to 1536 kbps on a T1 facility, or up to 1920 kbps on an E1 facility. In the switch, N x DS0 channels range up to 1984 kbps using nonfacility-associated signaling (NFAS) E1 interfaces. Also known as N x 64 kbps.
NAT
See Network Address Translation (NAT).
NetBIOS
Network Basic Input/Output System. A Microsoft protocol.
netmask
A portion of an IP address that identifies the bits that denote the network number.
Network Address Translation (NAT)
A feature that enables a LAN to use one set of IP addresses for internal traffic, and a second set of IP addresses for external traffic. This enables the use of many internal IP addresses within an intranet without causing collisions with public IP addresses on the Internet. The NAT device allocates a public IP address only when IP entities require service outside the firewall.
network mask
A portion of an IP address that identifies the bits that denote the network number.
network region
A group of IP endpoints and switch IP interfaces that are interconnected by an IP network.
NIC
Network Interface Card. Hardware that provides access from a computer to a LAN.
NMS
Network Management System.
node
A switching or control point for a network. Nodes are either tandem or terminal. Tandem nodes receive signals and pass the signals on, whereas terminal nodes originate or terminate a transmission path.
Nonfacility-Associated Signaling (NFAS)
A method of signaling in which multiple T1 and/or E1 facilities share a single D-channel to form an ISDN-PRI. If D-channel backup is not used, one facility is configured with a D-channel. The other facilities that share the D-channel are configured without D-channels. If D-channel backup is used, two facilities are configured with D-channels, with one D-channel on each facility. The other facilities that share the D-channels are configured without D-channels.
null modem cable
Special wiring of an RS-232-C cable that a computer can use to signal a printer or another computer without the need for a modem.
OAM
Operations, administration, and maintenance. A range of diverse management functions, including fault and performance management (operations); addressing, data collection, and usage monitoring (administration); and analysis, diagnosis, and repair of network faults (maintenance).
OC-3
See Optical Carrier level-3 (OC3).
OID
Object Identifier. Used in SNMP to identify managed objects. In the SNMP Manager/Agent Network Management Paradigm, each managed object must be identified by a unique OID.
Open system
A system based on established industry hardware and software standards so components from different vendors can work together.
Open Systems Interconnect (OSI)
A system of seven independent communication protocols defined by the International Standards Organization (ISO). Each of the seven layers enhances the communications services of the layer below, and shields the layer above from the implementation details of the lower layer. In theory, this structure can be used to build communication systems from independently developed layers.
Optical Carrier level-3 (OC3)
The Synchronous Optical Network (SONET) includes a set of signal rate multiples for transmitting digital signals on optical fiber. The base rate (OC-1) is 51.84 Mbps. OC-2 runs at twice the base rate, OC-3 runs at three times the base rate, and so on. Planned rates include OC-1, OC-3 (155.52 Mbps), OC-12 (622.08 Mbps), and OC-48 (2.488 Gbps). Asynchronous transfer mode uses some of the Optical Carrier levels. See also Synchronous Optical Network (SONET).
Out-of-Band
Transmission of auxiliary information, such as management messages, using frequencies or channels outside the frequencies or channels normally used for information transfer. Out-of-band signaling is often used for error reporting in situations in which in-band signaling can be affected by whatever problems the network might be experiencing.
packet
A group of bits used in packet switching that are transmitted as a discrete unit. A packet includes both a message element containing the data and a control Information Element (IE) containing the header. In each packet, the message element and the control IE are arranged in a specified format. See also Information Element (IE).
PAP/CHAP
Password Authentication Protocol/Challenge Handshake Authentication Protocol. Remote access protocols that identify the remote end-user so that the router or access server can determine if access is allowed.
PBX (private branch exchange)
A private telephone switching system, usually located on a company’s premises, that connects internal extensions to one another as well as to the outside telephone network.
PING
Packet Internet Groper. Determines whether a specific IP address is accessible by sending a packet to the specified address and waiting for a reply.
PN
See Port Network (PN).
PNI
Port Network Interface.
PoE
Power-over-Ethernet.
Point Of Presence (POP)
A physical location where a carrier has presence for network access. A POP is usually a switch or a router. See also router; switch.
Point-to-Point Protocol (PPP)
A connection-oriented, packet-data protocol that is commonly used in support of dial-up access from a personal computer to an Internet Service Provider (ISP). PPP uses an analog line through the Public Switched Telephone Network (PSTN), but provides many of the benefits of a direct connection.
POP
See Point Of Presence (POP).
port interfaces
Interfaces that connect to trunks, voice links, data links, and communications equipment.
Port Network (PN)
A cabinet that contains a Time-Division Multiplex (TDM) bus and a packet bus to which port circuit packs, control circuit packs, service circuit packs, and power converter circuit packs can be connected. Each PN is controlled either locally or remotely by a Switch Processing Element (SPE). See also Time-Division Multiplex (TDM) bus.
POST Code
Power-On Self Test codes are transmitted by the SPE processor’s BIOS to report the status of the diagnostics as the system powers up. power failure transfer See Emergency Transfer Relay (ETR).
PPP
See Point-to-Point Protocol (PPP).
Predictive dialing
A method for automatically initiating outbound calls and passing each call to an agent when the call is answered.Predictive dialing uses advanced software that estimates the number of calls to be placed based on the number of agents available.
PRI
Primary Rate Interface. See Integrated Services Digital Network Primary Rate Interface (ISDN-PRI).
PRI Endpoint (PE)
The wideband switching capability introduces PRI endpoints on switch line-side interfaces. A PRI endpoint consists of one or more contiguous B-channels on a line-side T1 or E1 ISDN PRI facility, and has an extension. Endpoint applications have call-control capabilities over PRI endpoints.
Primary Rate Interface (PRI)
See Integrated Services Digital Network Primary Rate Interface (ISDN-PRI).
Proprietary system(PRI)
A system that relies on applications from a single vendor. Applications access the system through closed APIs that make it difficult to integrate with components from other vendors.
protocol stack
A layered set of protocols that work together to provide a set of network functions. Each intermediate layer uses the layer below it to provide a service to the layer above.
PSTN
See Public Switched Telephone Network (PSTN).
public network
A network to which all customers have open access for local and long distance calling.
Public Switched Telephone Network (PSTN)
The public worldwide voice telephone network.
[Normal Text Span]“Pure IP”
A marketing myth that there is only one way to adopt IP telephony. Real
customers need real choices to reliably and securely support both evolutionary and greenfield business strategies.
Q.931
The D-channel layer 3 specification for use in an ISDN recommended by the ITUT for basic telecommunications call control.
Q.932
A D-channel specification for the operation of supplementary services. Adjunct-Switch Application Interface (ASAI) uses Q.932 as the basis for providing CTI services.
QoS
See Quality of Service (QoS).
QSIG
Q.931 Signaling.
quadrant
A group of six contiguous DS0s in fixed locations on an ISDN-PRI facility. The term comes from T1 terminology, where quadrant means one-fourth of a T1, but an E1 ISDN-PRI facility (30B + D) has five quadrants. See also Digital Signal Level n (DS-n).
Quality of Service (QoS)
The measurement of transmission rates, error rates, and other characteristics to define the quality of the service that is provided to telephone subscribers or users of a network. QoS is of particular concern for the continuous transmission of high-bandwidth video and multimedia information.
queue
An ordered sequence of calls that are waiting to be processed.
queuing
The process of holding calls in order of arrival to await connection to an attendant, answering group, or idle trunk. Calls that are in a queue are automatically connected in a first-in, first-out sequence.
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