telephony acronyms and terms

Telephony Acronyms and TermsGeneral Telecom Terms

September 2008

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TELEPHONY ACRONYMS AND TERMS

Is the code that most computers use to represent displayable characters. An ASCII file is a straightforward text file without special control characters.

A charge number parameter that is normally included in the Initial AddressMessage to the succeeding carrier for billing purposes.

A network technology for both local and wide area networks (LANs andWANs) that supports both real-time voice and video data. The topology usesswitches that establish a logical circuit from end to end, which guaranteesquality of service (QoS). However, unlike telephone switches that dedicatecircuits end to end, unused bandwidth in ATM’s logical circuits can beappropriated when needed. For example, idle bandwidth in a videoconferencecircuit can be used to transfer data. ATM is widely used as a backbonetechnology in carrier networks and large enterprises, but never becamepopular as a local network (LAN) topology (see below). ATM is highly scalableand supports transmission speeds of 1.5, 25, 100, 155, 622, 2488 and 9953Mbps (see OC). ATM is also running as slow as 9.6 Kbps between ships atsea. An ATM switch can be added into the middle of a switch fabric toenhance total capacity, and the new switch is automatically updated usingATM’s PNNI routing protocol.

In the ISDN world is a full duplex, 64Kbps channel used for sending data.

In many US states a requirement of the Callers Emergency ServiceIDentification (CESID) is required. CESID is a number that uniquely identifiesthe device that dialled 911. The CESID is fed into the automatic locationidentification (ALI) database at the Public Safety Answering Point (PSAP) so that emergency services can be dispatched to the correct location.

Switching system in which a dedicated physical circuit path must existbetween sender and receiver for the duration of the “call”. Used bytelephony, circuit switching is often contrasted with contention and tokenpassing as a channel-access method, and with message switching and packet switching as a switching technique.

A telephone company that competes with the larger incumbent carriers(ILECs) through reselling the ILEC services and / or creating services that usethe ILEC’s infrastructure. The Regional Bells are ILECs; local phone companiesare frequently CLECs.

SALES AND TECHNICAL TRAINING MITEL 1

General Telecom TermsASCII (American Standard Codefor Information Interchange):

ANI (Automatic Number Identification):

ATM (Asynchronous Transfer Mode):

B Channel:

CESID:

Circuit Switching:

CLEC (Competitive LocalExchange Carrier):

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SALES AND TECHNICAL TRAINING


MITEL 2

CO (Central Office):

Codec:

Common Channel Signalling:

Compression:

CPE (Customer Premises Equipment):

DTMF (Dual-Tone Multi-frequency):

DSP (Digital SignalProcessors):

A typical large carrier that provides local switching (or sometimes referred toas the local incumbent). There are two types of central offices – the first iscalled an “end office” (EO) or “local exchange” (LE), which is the feeder anddistribution system to homes and offices. The end office provides customerservices such as call waiting and call forwarding.

The second type is the tandem office (toll office), which is a central office thatdoes not connect directly to the customer. Toll call record generation andaccounting used to be handled in the tandem offices.

(COder-DECoder) Hardware or software that converts analog sound, speechor video to digital code and vice versa (analog to digital – digital to analog).Codecs must faithfully reproduce the original signal, but they must alsocompress the binary code to the smallest number of bits possible in order to transmit faster. As network bandwidth increases, so does the demand for more audio and video, so compression is always an issue.

A method of signalling in which signalling information relating to amultiplicity of circuits, or relating to a function for network management, is conveyed over a single channel by addressed messages.

VoIP uses various compression ratios, ranging from G.711 to G.729a.Compression varies according to available bandwidth. The uncompressedG.711 format is a required codec for H.323 (VoIP) audio andvideoconferencing in order to allow connections to legacy telephone networks.

Is (1) Telephone terminal devices, such as handsets and private branchexchanges (PBXs), located on the customer’s premises. (2) Terminatingequipment, such as terminals, phones, routers and modems, supplied by the phone company, installed at customer sites, and connected to the phone company network.

A way of signalling consisting of a push-button or “touchtone” dial thatsends out a sound consisting of two discrete tones that are picked up andinterpreted by telephone switches (either PBXs or central offices).

All digital audio systems use DSP technology in order to differentiatebetween signal and noise. In telephone communication, too, much noisecreates problems in maintaining connections, and in VoIP systems the DSPcomponent provides features such as tone generation, echo cancellation, and buffering.




E911 (Enhanced 911):

Frame Packing:

Frame Relay:

FDM (Frequency Division Multiplexing):

Full Duplex:

Half Duplex:

LEC (Local ExchangeCompany):

LS (Loop Start Line):

LS / GS (Loop Start / GroundStart):

Technology allowing 911 calls from cellular phones to be routed to thegeographically correct emergency station (a.k.a. PSAP: Public SafetyAnswering Point). VoIP users currently have limited access to 911 services,and with some providers none, because VoIP is not geographically based.

The number of voice samples included in the same IP packet. Usuallyprogrammable on VoIP gateways, the frame packing directly affectsbandwidth requirements and latency.

High-performance interface for packet-switching networks. Frame relaytechnology can handle communications that have rapidly changingbandwidth requirements. It is a connection-oriented service that is capable of carrying up to 4096 bytes per frame.

Division of a transmission facility into two or more channels by splitting thefrequency band transmitted by the facility into narrower bands, each of which is used to constitute a distinct channel.

Full duplex communication means that both ends of the communication cansend and receive signals at the same time. A telephone conversation is anexample of full duplex communication. Some Ethernet devices can also run in full duplex mode when connected directly to Ethernet switches

Half duplex is a bi-directional communication path that signals can only flowin one direction at a time on. An ordinary telephone conversation is a duplexcommunication. Most inexpensive speakerphones in conference rooms arehalf-duplex communication. (If you’re speaking, you can’t hear anyone elseinterrupt. You have to pause to let others speak.). Basic Ethernet is the same,it can only send or receive, it can’t do both at the same time.

A telephone company that provides customer access to the world wide publicswitched network through one of its central offices.

A line on which a closure between the tip and ring leads is used to originateor answer a call. Loop start signaling is normally used by POTS lines, faxes,and key systems

LECs typically provide two types of analog-based dial tone switched trunks –loop start and ground start. PBXs work best on ground start trunks becausethose trunks can give them an on hook signal allowing for timely clearing.Ground start or GST is a method in which method a cable pair is temporarilygrounded to request dial tone.




MITEL 4

Packet-switched:

MAC (Moves, Adds, Changes):

PBX (Private BranchExchange):

PCM (Pulse Code Modulation):

POTS (Plain Old Telephone Service):

PSTN (Public Switched Telephone Network):

RJ-11:

RJ-45:

TDM (Time-divisionmultiplexing):

Toll Quality Audio:

Toll Switch:

A communications network that used shared facilities to route data packetsfrom and to different users. Unlike a circuit-switched network, a packet-switched network does not set up dedicated circuits for each session.

a)Packet: A basic message unit for communication across a network. A packet usually includes routing information, data, and (sometimes)error detection information

A term that is used when a user, typically on a TDM-based PBX, requiresaspects of their phones identity to be altered / removed / added.

Is a privately owned system for voice switching and other telephone relatedservices. It routes calls from the public telephone system within anorganization and allows direct internal calls.

Is a technique for converting analog signals into digital form that is widelyused by the telephone companies in their T1 circuits. Every minute of the day,millions of telephone conversations, as well as data transmissions via modem,are converted into digital via PCM for transport over high-speed intercitytrunks. In North America and Japan, PCM samples the analog waves 8,000times per second and converts each sample into an 8-bit number, resulting ina 64 Kbps data stream (a single DS0 channel). The sampling rate is twice the4 kHz bandwidth required for a toll-quality conversation

Nothing more than a standard telephone line.

The network of wires, signals, and switches that lets one telephone connectto another anywhere in the world. Some VoIP services provide a gatewayfrom the Internet to the PSTN and vice versa.

Standard 4-Wire connectors for phone lines.

Standard 8-Wire connectors for Ethernet networks

Is a scheme in which numerous signals are combined for transmission on asingle communications line or channel. Each signal is broken up into manysegments and given a time slot, each having very short duration. Thecomposite signal thus contains data from all the end users.

Audio transmission at the quality level of an ordinary long distance telephonecall. The standard of performance is generally a PCM line.

Is a telephone Central Office switch that generates toll call transactions.Today, the end office switches provide most of the call accounting.




VoIP (Voice over Internet Protocol):

WDM (Wavelength Division Multiplexing):

AMC (Application Management Center):

APC (Application Processor Card):

ASU (Analog Services Unit):

CIM (Copper Interface Module):

DN (Directory Number):

DNIC (Digital Network Interface Circuit):

E2T (Ethernet to TDM):

FIM (Fiber Interface Module):

ICP (IP CommunicationsPlatform):

LIM (Line Interface Module):

LMS (Learning Management System):

MAS (Mitel Applications Suite):

The technology behind Internet phones. VoIP works by digitizing voice signalsand sending them as packets through the same networking channels as your data.

Two or more colours of light on one fibre.

AMC (Application Management Center): Is a web portal that provides access,download, and management of Mitel® applications and licenses.

A within the skins application server that is supported on the Mitel 3300 ICP CX / CXi controllers.

An add-on device that provides additional analog functionality, outside of theMitel ICP controller.

A module that fits into the front of the Mitel ICP controller and provides aconnection point for additional analog functions (Ex. for the ASU II).

A term often used for a user’s extension number.

A Mitel term that is used for Mitel digital cards / circuits that are supported in the Peripheral Node.

A Mitel PCI card that is used as the internal gateway (for Ethernet to TDMconversion and vice versa) for the Mitel ICP controllers.

A module that fits into the front of the Mitel ICP controller and provides aconnection point for additional digital functions (Ex. for the NSU or Peripheral Node).

The name for Mitel IP-based communications solutions (PBXs).

A module that fits into the back of specific Mitel IP phones and provides a connection point for a LS trunk.

A general industry term for a database where participants can access trainingmaterial and resources and view their learning history.

A Mitel solution that provides the ability to have multiple Mitel applicationsresiding on the same server.

Specific Mitel Acronyms and Terms




MITEL 6

MMC (Mitel Mezzanine Card):

MOL (Mitel OnLine):

MSL (Mitel Standard Linux):

NSU (Network Services Unit):

ONS (ON premise Station):

OPS (Off Premise Station):

PKM (Programmable Key Module):

RTC (Real Time Control):

Superkey:

Zones:

A general term used for additional modules / cards used by the Mitel ICP controllers to provide additional functions (ex. DSP resources, embedded trunking).

The name of Mitel’s private web site for business partners.

The name given to Mitel’s specific code of Linux used with both the Mitel 3300 ICP MXe Server and Application Servers.

An add-on device that provides a connection point for digital-based trunks,outside of the Mitel ICP controller.

A Mitel term that is used for a standard analog card / circuit that resideswithin the building and provides analog device connectivity (ex. phone, fax, modem).

A Mitel term that is used for a standard analog card / circuit that residesoutside of the building and provides analog device connectivity (ex. a phoneis a remote building).

An add-on module to specific Mitel phones that provides users withadditional personal programmable keys for their phone.

RTC (Real Time Control): A Mitel PCI card that is used as the call processorcard for the Mitel ICP controllers.

A Mitel term for a specific key (often blue) found on specific Mitel phones.This key allows for the easy programming of features and functions on the phone.

A term used within the Mitel 3300 ICP that provides the ability for forcedcompression between compression capable Mitel IP phones




General Data Terms10BASE-T:

100BASE-T:

802.1p/Q:

802.1Q:

802.11:

802.3af:

Bandwidth:

Bluetooth:

Broadband:

CAT-3 (Category 3):

Unshielded twisted-pair, minimum Category 3, Ethernet cabling standard. Thetransmission rate is 10Mbps with a cabling limit of 100m from the Ethernetswitch or hub. It uses two pairs of a 4 pair cable with RJ45 connectors.

Unshielded twisted-pair, minimum Category 5, Fast Ethernet cabling standard. The transmission rate is 100Mbps with a cabling limit of 100m from the Ethernet switch or hub. It uses two pairs of a 4 pair cable with RJ45 connectors.

The 802.1p/Q standard introduced to standardize the various methods ofpriority and VLAN tagging that were being used by different manufacturers.An extra field for VLAN identification, which includes 3 bits for Priority, isinserted into the Ethernet frame.

This is a standard for Virtual LANs. It inserts an extra 4-bytes in the header for designating the VLAN. The extended header also includes the 802.1ppriority scheme.

A wireless LAN standard that defines both frequency hopping and directsequence spread spectrum solutions for use in the 2.4GHz ISM (Industrial,Scientific, and Medical) band. Typically 2Mbps data rate

An IEEE standard for powering network devices via Ethernet cable. Alsoknown as “Power-over-Ethernet,” it provides 48 volts over 4-wire or 8-wiretwisted pair. The 8-wire cable uses one twisted pair for the power, while the 4-wire transmits the power over the same pair as the data, but usesdifferent frequencies

Refers to the difference (measured in Hz), between the highest and lowestfrequencies of a transmission. Most people loosely refer to bandwidth as the amount of data that can be transferred over a network connection.

Bluetooth is a computing and telecommunications industry specification thatdescribes how mobile phones, computers, and personal digital assistants caneasily interconnect with each other and with home and business phones andcomputers using a short-range wireless connection.

A transmission system in which signals are encoded and modulated intodifferent frequencies and then transmitted simultaneously with other signals.(Ex. cable television uses broadband techniques to deliver dozens of channelsover one cable.

Is the industry standard for unshielded twisted pair capable of supportingvoice and low-grade data traffic. Minimum requirement for 10Base T Ethernet.




MITEL 8

CAT-5 (Category 5):

Firewall:

FTP (File Transfer Protocol):

HDD (Hard Disk Drive):

G.711:

G.721:

G.723.1:

G.728:

G.729:

H.323:

IP Address:

Is a higher grade of unshielded twisted-pair cable available. Category 5 UTP is required to run Fast Ethernet.

Security software or appliance that sits between the Internet and theindividual PC or networked device. Firewalls can intercept traffic before itreaches network routers and switches, or between router / switch and PC, or both. Because the job of firewalls is to prevent access from specific packetsover specific network ports, some must be specially configured to allow VoIPtraffic to pass through.

The most popular way of downloading (get) and uploading (put) files acrossan Internet connection. There is a set of commands in FTP for making andchanging directories, transferring, copying, moving, and deleting files. FTPclients exist for nearly all platforms.

Commonly referred to as a hard drive

The standard voice encoding scheme providing toll quality digitally encodedvoice at 64Kbps.

An ADPCM compression scheme providing digitally encoded voice at 32Kbps

A CELP dual rate speech encoder for multimedia communicationstransmitting at 5.3 and 6.3Kbps

A CELP based CODEC that provides digitally encoded voice 16Kbps with lowdelay. There are several revisions.

Sometimes also referred to as CS-ACELP. G.729 offers similar voice quality to32Kbps ADPCM but at only 8Kbps, with moderate transmission delays. Thereare several revisions including G.729a and b.

The standard call protocol for voice and videoconferencing over LANs, WANs,and the Internet, allowing these activities on a real-time basis as opposed toa packet-switched network. Initially designed to allow multimedia to functionover unreliable networks, it’s the oldest and most established of the VoIPprotocols. See also SIP and MGCP.

The 32-bit address defined by the Internet Protocol. Every resource on theInternet has a unique numerical IP address, represented in dotted decimalnotation. IP addresses are the closest thing the Internet has to phonenumbers. When you “call” that number (using any number of connectionmethods e.g. HTTP, etc.) you get connected to the computer to which that IP address is assigned.



The fundamental unit of information passed across the Internet. Containssource and destination addresses along with data and a number of fieldswhich define such things as the length of the datagram, the headerchecksum, and flags to say whether the datagram can be (or has been) fragmented.

An object-oriented programming language developed by Sun Microsystems.Applets written in Java include their own software players, so you candownload and run them on any computer.

Jitter is the variation in delay or latency that occurs in a network. Jitter can be caused by networks experiencing congestion problems such as processorqueues and bandwidth overload. Voice is particularly susceptible to jitter.

A network interconnecting devices in the same office, floor, or building, orareas inside buildings with areas just outside. LANs are now commonplace in most businesses, allowing users to send email and share resources such as files, printers, etc.

A system that implements classic PBX functions over a LAN. It is able to bewired over a data LAN (e.g. Ethernet) and may include IP phones and / or PC based soft phones.

Dividing LAN bandwidth into multiple independent LANs to improve performance.

The time it takes for a packet to travel from its point of origin to its point ofdestination. In telephony, the lower the latency, the better the communicationsounds. Latency has always been an issue with telephone communicationtaking place over exceptionally long distances (the United States to Europe,for example). With VoIP, however, latency takes on a new form because of the splitting of the message into packets and network delay in general.

On a local area network or other network, the MAC address is the IP device’s unique hardware number that is associated with and is hard codedinto the NIC.

A data communication network covering the geographic area of a city(generally, larger than a LAN but smaller than a WAN).

Another protocol competing with H.323, MGCP handles the traffic betweenmedia gateways and their controllers. Especially useful in multimediaapplications: the media gateway converts from various formats for theswitched-circuit network, and the controller handles conversion for thepacket-switched network.


IP Datagram:

Java:

Jitter:

LAN (Local Area Network):

LAN PBX:

LAN Segmentation:

Latency:

MAC Address (Media AccessControl Address):

MAN (Metropolitan Area Network):

MGCP (Media Gateway Control Protocol):




MITEL 10

The circuit board or other hardware that provides the interface between acommunicating DTE and the network.

Is a 7 layer standard reference model for communication between two endusers in a network. The model is used in developing products andunderstanding networks. Quick saying to remember it – All People Seem To Need Data Processing.

• Layer 7: The application layer...is where the communicationpartners are identified, quality of service is identified, userauthentication and privacy are considered, and any constraints on data syntax are identified. (This layer is not the application itself, although some applications may perform application layer functions.)

• Layer 6: The presentation layer...is usually part of an operatingsystem, that converts incoming and outgoing data from onepresentation format to another (for example, from a text stream into a popup window with the newly arrived text).

• Layer 5: The session layer...sets up, coordinates, and terminatesconversations, exchanges, and dialogs between the applications at each end. It deals with session and connection coordination.

• Layer 4: The transport layer...manages the end-to-end controland error-checking (for example, determining whether all packetshave arrived). It ensures complete data transfer.

• Layer 3: The network layer...handles the routing of the data(sending it in the right direction to the right destination on outgoingtransmissions and receiving incoming transmissions at the packetlevel). The network layer does routing and forwarding.

• Layer 2: The data-link layer...provides synchronization for thephysical level and does bit-stuffing for strings of 1’s in excess of 5. It furnishes transmission protocol knowledge and management.

• Layer 1: The physical layer...conveys the bit stream through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier.

Also known as Real Time Transport Protocol. Controls the transmission of packets of data that demands low latency (such as audio and video).Supports real-time transmission over IP networks and streaming as onemeans of delivery.

Refers to the quality of the voice call over a VoIP network. A major issue inVoIP communications, because the high quality of telephone calls has alwaysbeen taken for granted. Latency, packet loss, network jitter, and many otherfactors contribute to QOS measurements, and numerous solutions have beenoffered by vendors of routers and other network components.

NIC (Network Interface Card):

OSI Model (Open Systems Interconnection):

RTP (Real Time Protocol):

QOS (Quality of Service):



Communication protocol that operates similarly to H.323 but is less complexand more Internet- and Web-friendly. Fully modular and designed from theground up for functioning over IP networks, it can be tailored more easilythan H.323 for Internet applications. SIP and H.323 can and do coexist.

A protocol used to transfer email. SMTP transfers mail from server to server,and the end user must use Post Office Protocol to transfer the messages totheir machine.

An algorithm that allows redundant bridges to be used for network resilience,without the broadcast storms associated with looping. If a bridge fails, a newpath to a redundant bridge is opened. Part of the 802.1D standard.

Is a version of RTP that provides confidentiality and message authenticationof packets being transported over data networks.

A communications protocol developed under contract from the U.S.Department of Defense to inter-network dissimilar systems. The TCP / IP suiteprovides two transport methods: TCP ensures that data arrive intact andcomplete, while UDP just sends out packets. TCP is used for everything thatmust arrive in perfect form, and UDP is used for streaming media, such asVoIP and videoconferencing, where there is no time to retransmit droppedpackets in real-time.

The reliable transport protocol within the TCP / IP protocol suite. TCP ensuresthat all data arrive accurately and 100% intact at the other end. TCP’sunreliable counterpart is UDP, which is used for streaming media, VoIP andvideoconferencing. TCP is “connection oriented” and requires a handshakebefore the session can begin.

A simplified version of FTP allowing the transfer of files from one computer to another over a network.

A protocol within the TCP / IP protocol suite that is used in place of TCP whena reliable delivery is not required. There is less processing of UDP packetsthan there is for TCP. UDP is widely used for streaming audio and video, voiceover IP (VoIP) and videoconferencing, because there is no time to retransmiterroneous or dropped packets. UDP is “connectionless” and does not use ahandshake to start a session. It just sends out packets.

Virtual LANs are a method of isolating traffic in Ethernet Switches. There were many proprietary schemes before and 802.1Q standardised these VLAN schemes. Membership to a Virtual LAN is defined administrativelyindependent of the physical network topology. A virtual LAN segment is a unique broadcast domain.


SIP (Session InitiationProtocol):

SMTP (Simple Mail Transfer Protocol):

STP (Spanning Tree Protocol):

SRTP (Secure RTP):

TCP / IP (Transmission ControlProtocol / Internet Protocol):

TCP (Transmission Control Protocol):

TFTP (Trivial File Transfer Protocol):

UDP (User DatagramProtocol):

VLAN:




MITEL 12

A private network that is configured within a public network (a carrier’snetwork or the Internet) in order to take advantage of the economies of scaleand management facilities of large networks. VPNs are widely used byenterprises to create wide area networks (WANs) that span large geographicareas, to provide site-to-site connections to branch offices and to allowmobile users to dial up their company LANs.

Voice Extensible Mark-up Language is a mark-up language to define voiceaccess to Web-based applications.

A network that uses common carrier lines to form a private (data) networkover an extended geographical area.

(Wireless Local Area Network)

Is used for documents containing structured information. Structuredinformation contains both content (words, pictures, etc.) and some indicationof what role that content plays (for example, content in a section heading hasa different meaning from content in a footnote etc.). Almost all documentshave some structure. A mark-up language is a mechanism to identifystructures in a document. The XML specification defines a standard way to add mark-up to documents.

VPN (Virtual Private Network):

VXML:

WAN (Wide Area Network):

WLAN:

XML (eXtended Markup Language):


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M MITEL (design) is a registered trademark of Mitel Networks Corporation. All other products and services are the registered trademarks of their respective holders.

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telephony acronyms and terms

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