Below is a list of common terms and their definitions.

ANI

Automatic Number Identifier

Audit Support Service

Professional service that investigates, identifies, validates, and corrects billing problems

Bandwidth

Capacity of a communications circuit or channel

Billing Increment

Minimum unit of billing for communication time. Units range from 6 seconds to 1 minute increments

Billing Inventory

A comprehensive list of services being billed through invoices to an organization by vendors

Business Line

Circuit connecting the LEC central office to telephone equipment or single line devices such as fax or modem

Call Block

Lets a user prevent calls from specific numbers

Caller ID

Identifies the telephone number and name of calling party

Call Waiting

Signals a user during a call in progress that another caller is attempting to get through

Carriers

Companies that provide telecommunications services

Central Office

Telephone company facility or equipment for switching and routing telephone calls

CLEC (Competitive Local Exchange Carrier)

A telecommunications provider company (sometimes called a "carrier") that competes with other already established carriers (generally the incumbent local exchange carrier (ILEC)

Contract Negotiations Service

Professional service that negotiates the best possible telecom vendor contracts for an organization

Cost Optimization

The process of reviewing an organization’s current telecom environment and working to change it in ways that will save money

Cramming

Phone fraud in which a telephone company adds services to a user's telephone bill without the user's consent

Credit Recovery

The process of identifying and confirming billing errors and working with vendors to recover money spent on incorrect charges.

Dedicated Long Distance

Long Distance service that has a dedicated point to point digital service between the customer location and the Inter-Exchange Carrier (IXC)

Demarc

Location on customer premises separating telephone company facilities and connecting with customer facilities

DID (Direct Inward Dialing)

A feature offered by telephone companies for use with their customers' PBX systems, whereby the telephone company allocates a range of numbers all connected to their customer's PBX. As calls are presented to the PBX, the number that the caller dialed is also given, so the PBX can route the call to the desired person within the organization

DS1 (Digital Standard 1)

Defines characteristics for circuits and associated equipment providing that two way digital transmission at 1.544 MBPS, often time division multiplexed into 24 voice grade channels of 64 KBPS

DS3 (Digital Standard 3)

Defines characteristics of circuits and associated equipment providing two way digital transmission at 44.736 MBPS, often time division multiplexed into 672 voice grade channels of 64 KBPS

E1

The European equivalent of the North American T1. Carrier system transferring digital signals at 2.048 MBPS, providing 32 64 KBPS channels of which two are used for signaling and control

Erlang

A measurement of telephone traffic. One Erlang is equal to one full hour of use, or 60 x 60 =3,600 seconds of phone conversation

Flat Rate Service

Local calling plan which allows unlimited local usage at no additional charge

ILEC (Incumbent Local Exchange Carrier)

An established, facilities-based telecommunication carrier offering local telecommunications services

Individual Business Line

A single telephone line used by a business enterprise.

Individual Liability Accounts

Contracts signed between wireless providers and individuals for services and devices. In these contracts the liability for all bills lies with the individual under contract with the carrier

IntraLATA

Services that originate and terminate in the same LATA

Intrastate

Long Distance calls that originate and terminate within the same state, falling under the jurisdiction of that state’s telephone regulatory procedures

InterLATA

Traffic of facilities that originate in one LATA, crossing over and terminating in another LATA

Interstate Long Distance

Long Distance calls between two states

IXC (Interexchange Carrier)

A telephone company providing telecommunications service to connect end users located in different local exchange areas, but excluding companies which also provide noncompetitive local exchange services

LATA (Local Access and Transport Area)

Represents a geographical area in the United States within which a local telephone company may offer telecommunications services

LEC (Local Exchange Carrier)

Provides local telephone service and access to the national networks

Local Loop

Physical link that connects from the demarcation point of the customer premises to the carrier’s Central Office

LPIC (Intralata Primary Exchange Carrier)

Designation provided to each telephone number for determining which long-distance carrier will handle Intralata calls with dialing 1+

Measure Rate Service

Local calling plan that bills for each completed outgoing local call

Move Support Service

Professional service that facilitates any changes, additions or deletions of telecom services

Multiplexing

To transmit two or more signals over a single channel

NPA/NXX

First six digits of a North American Telephone Number; the area code and exchange

PBX (Private Branch Exchange)

System of telephones that gives station users access to internal and external lines from one telephone set

Physical Inventory Service

The process of locating and identifying telecom services that are being billed by telecom vendors

PICC (Primary Interexchange Carrier Charge)

Monthly fee that may be applied to each local telephone line to allow for routing of long distance services to the long distance provider

PIC (Primary Interexchange Carrier)

Designation provided each telephone number for determining which long-distance carrier will handle Interlata, Intrastate, and Interstate calls with dialing 1+

PIC Freeze

When a customer tells the Local Telephone Company that no one is allowed to change the long distance company being used except for the actual customer. It is designed to prevent unauthorized changing of a customer’s long distance telephone carrier

POTS (Plain Old Telephone Service)

Usually a single dial tone line with no added features

PRI (Primary Rate Interface)

ISDN equivalent of a T1 circuit. The Primary Rate Interface provides 23B+D channels running at 1.544 MBPS with 23 - B (Bearer Channels - 64KBPS) and 1 - D (Data Channel for management)

PSTN

Public Switched Telephone Network

PTT (Post Telephone & Telegraph)

Government owned or controlled telephone company in many countries outside the United States

RBOC

Regional Bell Operating Company

Signaling System 7

Out of band signaling protocol used by Public Switched Telephone Networks

Slamming

The practice of changing the long distance service of a customer without authorization

Switched Long Distance

Long Distance services provided via local switched access circuit

TDM (Time Division Multiplexing)

A method used to send multiple signals over a common transmission path by assigning different time slots to each signal

Trunk

Circuit engineered to connect the Local Exchange Carrier’s Central Office to a PBX system for Business Class Switched Services

Toll Free Service

Telephone calls that are paid for by the individual or corporation that rents the number, i.e., 800, 888, 866 numbers

USF (Universal Service Fund)

Under the direction of the FCC a carrier fee charged to customers which helps compensate telephone companies for providing access to telecom services at reasonable and affordable rates across the United States

USOC (Uniform Service Order Code)

A structured language utilized by the carriers that allows for the development of software to support service order systems in the telecom industry. The service order process utilizes the USOC, along with field identifiers (FIDs), to provision, bill and maintain services and equipment

Wireless Corporate Account

A corporate ownership of wireless devices, services, and cellular telephone numbers. Typically under a service contract that provides discounts not available to the general public

Wireless Devices

Wireless devices use electromagnetic waves, rather than some form of wire, to carry and transmit a signal. Some examples include cellular telephones, smartphones and tablets