Glossary of Telecom Terms : A

Even experts need occasional help with telecom terms. We have combined glossaries from several sources to simplify finding the definitions you need.

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Abbreviated Bill
Two-page hard copy summary version of the CLEC or Reseller monthly bill.


See Alternate Billed Call.


Acceptance Limit (AL)
The maximum margin, value, or deviation that is allowed at service turn-up or end user acceptance.



  1. The method, time, circuit, or facility used to enter the network.
  2. The service provided by local exchange carriers or alternate access providers, that connects an Interexchange carrier with its customers. There are two kinds of access services:

Access Billing Customer Service Record
The Access Billing Customer Service Record (CABS) inquiry allows CLEC to view Platform/UNE P service records.The Access Billing CSR inquiry is available in Verizon North (New York and New England). Learn more.


Access Charge
A charge billed to Interexchange Carriers for the origination and termination of interexchange calls through a Local Exchange Carrier (LEC).


Access Code
A short sequence of digits assigned by the telephone service provider to an individual customer to provide access to a specific service, feature or function of a telecommunications network or computer system. The five-digit code (used for call destinations within the United States) has the form 10XXX; the seven-digit code (used for international call destinations) has the form 101XXXX or 950-XXXX.


Access Carrier (or Customer) Name Abbreviation (ACNA)
A three-character code assigned to each Interexchange Carrier; designates the customer to which circuits are billed.


Access Line
The portion of a telephone line between the end user's location and the telephone service provider's central office. Also called local loop, subscriber loop or local line.


Access/Local Tandem Switch
Switching systems that concentrate and distribute traffic originating from or terminating at end offices in the access/local service area. See tandem switch.


Access Method

  1. The method by which networked stations determine when they can transmit data on a shared transmission medium.
  2. Software within an SNA processor that controls the flow of information through a network.

Access Minutes
The elapsed time, figured in minutes, between the start of an access attempt and successful access.

Access Ordering
Verizon application for access ordering, pre-ordering and post-ordering. Provides for: Service Address Verification, CFA and SONET Ring Validation, View Confirmation Notices and Design Layout Records, Create an ASR profile and templates. Learn more.


Access Rate
The transmission speed, in bits per second, of the physical access circuit between the end user and the network.


Access Service Ordering Guidelines (ASOG)
Industry guidelines for issuing Access Service Requests (ASRs) as sponsored by the Ordering and Billing Forum (OBF) and the Alliance for Telecommunications Industry Solutions (ATIS). These guidelines outline the forms, data elements and the business rules necessary to create an Access Service Request. Learn more.


Access Service Request (ASR)
Forms used by Interexchange Carrier customers to order Switched Access or Special Access Services from Verizon; for example, interoffice facilities such as dedicated trunk ports.


Access Tandem
Switching system that concentrates and distributes traffic originating from or terminating at end offices in the access/local service area. See tandem switch.


Access Tandem Connection (ATC)
The interconnection between a Verizon tandem switch and another service provider's switching entity/Point of Interface over which local traffic, EAS or IntraLATA traffic may flow to and from the end offices subtending the interconnection tandem switch.


Access Validation Engine (AVE)
Verizon System that will validate an ASR prior to it being accepted by Verizon ordering applications. Learn more.


Account Management
Primary point of contact for the Verizon Wholesale customers.


See Access Carrier (or Customer) Name Abbreviation.


Address Table
A table stored in routers, bridges and switches that enables these devices to know where on the network to forward information.


Address Validation Inquiry
The Address Validation Inquiry is a local preorder transaction that allows CLECs to validate an end user's address. Learn more.


A correction (often in the form of a credit) made to a customer's account when billing errors have been properly documented.


See Asymmetric Digital Subscriber Line.


ADSL Compatible Unbundled Loop 2 Wire
A Verizon Wholesale unbundled loop service consisting of a loop facility extending from the Central Office Distribution Frame (MDF) to the end user Customer Premises Network Interface Device, that is compatible with ADSL technology, allowing concurrent transmission of high speed data communications and POTS. Learn more.


Advanced Intelligent Network (AIN)
A telephone network architecture that adds advanced computer intelligence to the telephone system. AIN supports advanced telecommunications features such as voice recognition.


As defined in the Telecommunications Act of 1996, a person or entity that (directly or indirectly) owns or controls a telecommunications company, is owned or controlled by, or is under common ownership or control with, another person or entity.


A person or entity who acts on behalf of another person or entity with the principal's authorization.


See Advanced Intelligent Network.


AIN Query
Advanced Intelligent Network query capability on a Verizon AIN.


AIN Triggers
A Verizon Wholesale UNE service offering used in conjunction with service provider designed and constructed AIN service logic built using the Verizon AIN Service Management System (SMS).


See Acceptance Limit.


See Automatic Location Identification/Data Management System.


Alliance for Telecommunications Industry Solutions (ATIS)
Trade group for telecommunications carriers, resellers, manufacturers and providers of enhanced services. ATIS is heavily involved in standards issues including interconnection and interoperability issues.


Alternate Billed Call (ABC)
A call originating on one line and charged to another, using collect, bill-to-third (Third Number) or calling card.


Alternate Exchange Carrier Name (AECN)
A unique identifier for a CLEC.


Alternate Mark Inversion (AMI)
A DS1 line code that does not perform zero code suppression and is therefore transparent to an all-zeros byte.


See Automated Message Accounting.


American National Standards Institute (ANSI)
An organization that certifies standards developed by a wide variety of industry groups. ANSI does not create standards, but rather consolidates those which have been created by other organizations.


See Alternate Mark Inversion.


Analog Line Ports
A Verizon Wholesale UNE offering that provides a 2-wire electrical interface to the local switch. Learn more.


Analog Transmission
The traditional telephone technology (for voice transmission) in which sound waves (or other data) are converted into electrical impulses of varying strength or amplitude.


Analog 2-Wire and 4-Wire Loop
Verizon Wholesale services that provide four signaling options that are determined by point-of-termination characteristics. 2-wire analog loops support POTS while 4-wire loops let you configure other types of circuits in different ways. Learn more.


Analog Unbundled Loop with Customer-Specified Signaling
A service offered by Verizon for the transmission of analog signals from a customer's premises to the Main Distribution Frame (MDF) in a Verizon central office.


Ancillary Telecommunications Services
Subordinate, supplementary and subcomponent characteristics and capabilities of telecommunications services that are made available to Enhanced Service Providers by Local Exchange Carriers. An example of an ancillary service is protocol conversion.


See Automatic Number Identification.


See American National Standards Institute.


Applications Group
A group that tests application data transfer; and approves production if the test is successful.


Application-to-Application Interface
The point (interface) at which data can be exchanged between the CLEC or Reseller application and the Verizon Operations Support Systems (OSS). The CLEC or Reseller can purchase an application from an industry vendor, or have it custom-built. Commonly referred to as App-to-App.


Appointment Scheduling Inquiry
A Verizon Wholesale local pre-order transaction used to check installation dates.


Area Code
Also known as a Numbering Plan Area (NPA). A three-digit code that identifies the local calling area.


See Access Service Ordering Guidelines.


See Access Service Request.


Asymmetric Digital Subscriber Line (ADSL)
A transmission technology that transmits an asymmetric digital signal using one of a variety of line codes as specified in the ANSI standard. ADSL technology enables data transmission over existing copper wiring at data rates several hundred times faster than analog modems, providing for simultaneous delivery of voice, video and data.


Asynchronous Protocol
A type of transmission in which information is sent at random, at any speed with no routing information.


Asynchronous Transfer Mode (ATM)
Asynchronous Transfer Mode (ATM) Network Service is a form of 'fast packet' switching service for high speed networks which require flexible bandwidth, high-performance transport and switching for connectivity between and among widely distributed customer locations.


See Access Tandem Connection.


See Alliance for Telecommunications Industry Solutions.


See Asynchronous Transfer Mode.


ATM Forum
A telecommunications industry organization that focuses on the development, standardization and deployment of ATM products.


Automated Message Accounting (AMA)

  1. The automatic collection, recording and processing of information relating to calls for billing purposes.
  2. The structure inherent in switch technology that initially records telecommunication message information. The industry standard for AMA format is contained in a Telcordia Technologies document, Automated Message Accounting.

Automated Telephone Listing Address System (ATLAS)
Central repository for Verizon Listings data. Input data is from Verizon Retail, Wholesale, and Independent service providers. ATLAS users include Verizon Directory Assistance and Directory Publishing.


Automatic Location Identification/Data Management System (ALI/DMS)
The Verizon emergency services (E911/911) database that contains customer location information (including name, address, telephone number, and sometimes special information from the local service provider). This information is used to process subscriber access records into Automatic Location Identification (ALI) records, which are used in response to 9-1-1 calls. Verizon uploads records from this database to the ALI Gateway for downloading by local ALI database systems. The selective router ALI (SR/ALI) uses these records to determine the appropriate Public Safety Answering Point (PSAP) for routing emergency calls.


Automatic Number Identification (ANI)
The number transmitted through the network that identifies the calling party. Technically, a Common Channel Inter-office Signaling (CCIS) parameter that refers to the number transmitted on an out-of-band basis through the SS7 signaling network identifying the calling party's telephone number. Also known as Calling Party Number (CPN).


Auxiliary Interconnection
An interconnection between a Verizon switch and another service provider's switching entity/Point of Interface for the provisioning of ancillary services such as Operator Services.


See Access Validation Engine.



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