Telecom Library

8XX    Toll free number as in 800, 888, 877, 855, etc
Abbreviated Dialing

A feature that permits the calling party to dial the destination telephone number in fewer than normal digits. Abbreviated Dialing numbers must be set up in advance of their use. Typically used in private networks or speed dial functionality.

Access Rate or Access Speed The transmission speed of the physical access circuit between the end user location and the local network. This is generally measured in bits per second.
Account CodesAlso known as Project Codes or Bill-Back Codes. Account Codes are additional digits dialed by the calling party that provide information about the call. Typically used by hourly professionals (accountants, lawyers, etc.) to track and bill clients, projects, etc.
ADSL – Asymmetric Digital Subscriber Line

This allows transmission of digital video and data in one direction over a regular copper line at a relatively high speed of 1.5 megabits a second, which is on par with a TI line. Upload speeds are typically much slower than download speeds.

ARD – Automatic Ring Down Circuit

A leased voice circuit that connects two single endpoints together. When either handset is taken off-hoo, the remote phone automatically rings.

ASP – Application Services Provider

An organization that hosts software applications on its own servers with its own facilities.

ATM – Asynchronous Transfer ModeThis is a high-speed transmission line that carries two-way voice, video, and data at super-high speed over a combination of copper and fiber. The current speed limit of 155 megabits per second will soon be exceeded by a 622-megabit version.
Backbone A segment of a network used to connect smaller segments of networks together. Backbones carry high concentrations of traffic between on and off ramps of networks.
BandwidthThe measure of the capacity of a communications channel. Analog telephone lines measure capacity in hertz, the difference in the highest and lowest frequency of the channel. Digital channels measure bandwidth in bits per second.
BallotA release form that authorizes a customer’s long-distance phone service to be switched to (another) long-distance carrier, or reseller. Also know as a Letter Of Agency or LOA.
BRI – Basic Rate Interface The integrated services digital network (ISDN) interface made up of two B channels at 64 kilobits each and a signaling channel with a speed of 16 kilobits.
BANBilling Account Number Used by telephone companies to designate a customer or customer location that will be billed. A single customer may have multiple billing accounts.
BitA contraction of “binary digit.” A bit is the smallest element of information in the digital system.
BER – Bit Error RateThe ratio or bits with errors to the total number of bits detected, usually expressed as a number with an exponent to a power of 10. Used to measure the quality of a signal path.
Block CallsPrevent calls from completing to the requested destination. May be due to network problems (outage, overload, etc.), or by customer request (e.g. block calls from-or-to certain area codes, states, LATAs, etc.).
BroadbandA high-speed connection to the Internet, typically defined as starting at 384 kbps. It allows rich media content (content that uses video, audio or complex graphics like those used in high end computer games) to quickly flow across the network to the user’s computer ..
BTN – Billing Telephone NumberThe phone number associated, for billing purposes, with the Working Phone Number.
BypassAccess an IEC other than the customer’s Equal Access carrier by dialing 10+CIC Code. ( e.g . Bypass to WorldCom by dialing “1010555”). See Walkthrough, CIC Code
Calling Card A telecommunication credit card with an authorization code for using a long distance carrier when the customer is away from their home or office (ANI).
Central OfficeThis is a local phone company building where all phone lines in the surrounding geographic area terminate. From this point the calls are switched, or routed, to another local phone connected to the same central office or to another central office.
CentrexA service that is functionally similar to a customer-premise PBX, but provided by means of equipment located in a Central Office.
Circuit SwitchingA switching system that establishes a dedicated physical communications connection between end points, through the network, for the duration of the communications session; this is most often contrasted with packet switching in data communications transmissions.
CLEC – Competitive Local Exchange Carrier

A competitor to traditional LRC

CNAM – Carrier Number Administration Manager

Typically used in local number portability and 8XX management.

COS – Class of ServiceA special limitation on what numbers can and cannot be called. International, 809, 809 + Canada , 48 contiguous states, etc.
Collect A call that is paid for by the receiving/destination phone number. Requires approval/authorization of the person being called.
ContractA legally binding agreement between a vendor and a customer to provide Products, Services or Features in a specified quantity and quality, for a specified price, during a specified period of time.
Country Code Two or three digit codes used for International calls outside of the North American Numbering Plan area codes. Dial: 011 + country code + city code + local phone number) (e.g. “011 + 91 + 22 + 123- 4567” 91 = India , 22 = Bombay )
CPE – Customer Premise EquipmentAny equipment — such as telephones, computers, printers, video equipment or other items — that a user can connect to a network.
CSU/DSU – Channel Service Unit/Data Service Unit A digital interface device that connects customer computers, video equipment, multiplexers, and terminals to digital telephone lines.
CutoverThe exact date/time that a phone number, circuit, etc. is scheduled to be (or was) moved from one implementation (carrier, etc.) to another. ( e.g . moving an 800 number from MCI to Wholesale Carrier Services).
DAL- Dedicated Access LineA non-switched circuit from the customer to a carrier.
DDD – Direct Distance DialingAny switched telecommunication service (like 1+, 0++, etc.) that allows a call originator to place long distance calls directly to telephones outside the local service area without an operator.
DeactivationA request to terminate service (or the process of terminating service).
Dedicated Line

A private line leased from a telecommunications carrier that runs between two or more sites of a private network. Dedicated lines are always available for the exclusive use of the private network at a fixed monthly fee.

Default CarrierYour regular Dial-1 carrier. Call 1-700-555-4141 to find your default carrier.
DialTo place a call on a switched network. The term “dial” is obsolete – based on rotary dial phones and electromechanical relay switches (which are nearly non-existent in modern telephone systems.) Touch Tone service recognizes dual tones that are generated as each telephone key is pressed. Where Touch Tone service is not available, telephones and switches electronically “pulse” signals that emulate the older rotary dial telephones. The terms “place” a call or “originate” a call are more accurate than “dial”.
Dial ToneReady To Place/Originate A Call. When the off hook indication is received at a central office, a dial tone signal is sent to the originating caller on a switched network to indicate that the switch is ready to accept a number.
DialerEquipment that pulses out a standard dial protocol signal.
Dial-up AccessThe process of initiating a switched connection through the network for a computer. Dial-up connections operate much more slowly than DSL connections and are inherently not “always on.”
DigitalA device or method that uses discrete variations in voltage, frequency, amplitude, location, etc. to encode, process, or carry binary (zero or one) signals for sound, video, computer data or other information. For example, a digital clock displays the time as discrete numeric values, rather than angular displacement of analog hands. Digital communications technology generally permits higher speeds of transmission with a lower error rate than can be achieved with analog technology. When analog signals are received and amplified at each repeater station, any noise is also amplified. A digital signal, however, is detected and regenerated (not amplified). Unlike amplification, any noise (less than a valid signal) is eliminated by digital regeneration.
DSL – Digital Subscriber LineA proven technology that takes advantage of standard copper telephone lines to provide secure, reliable, high-speed Internet access.
DA – Directory Assistance

An information service whereby operators assist customers in obtaining the telephone number(s) they wish to call.

Equal Access(AT&T Divestiture – 1982 Modified Final Judgement) The provision of one-plus capability to interLATA competitors of AT&T. Customers should be able to reach the carrier of their choice by dialing 1+ the long-distance number. The MFJ and the FCC require local exchange carriers to provide equal access (most central offices now have this capability). Equal Access may also refer to a more generic concept under which the BOCs must provide access services to AT&T’s competitors that are equivalent to those provided to AT&T.
EthernetA native electrical interface standard typically used in LANs and WANs. Available speeds10base T=10 Mbps,100baseT=100 Mbps and Gigabit=1000Mbps.
FBC – Facilities-Based CarrierA carrier that uses its own facilities to provide service, in contrast with resellers, that purchase the services of other carriers and then retail the services to customers. (Most facilities-based carriers use the services of other carriers to some extent.)
FCC – Federal Communications CommissionRegulates interstate communications: licenses, rates, tariffs, standards, limitations, etc. Appointed by U.S. President.
Frame Relay

Digital fast packet data relay protocol used for transmitting fixed sized “cells” of data at speeds typicall up to 45 Mbps. A common, more economical and operational efficient data transmission type than traditional private line or leased line network service.

FTP – File Transfer ProtocolFile Transfer Protocol is the process by which complete files can be transmitted from one computer to another. In order for this to work successfully, certain protocols must exist between communicating computers. The protocol used depends upon the type of files that are being sent or received.
FirewallA firewall is a security measure that consists of a separate computer that acts as a ‘bouncer’ between the Internet and an internal network. Its job is to sift through all incoming traffic and turn away any undesirables and also to implement security measures.
Frame RelayA high-speed packet switching protocol used in WANs .It provides a service up to DS3 speeds (45 Mbps) and is popular for LAN connections across remote distances.
Home PageA home page is the default first page of a World Wide Web site that users see when they visit an organization’s Web site. A home page is analogous to the first page and table of contents of a book.
HTMLHypertext Mark-up Language. Simple hypertext document formatting language that uses tags to indicate how a given part of a document should be interpreted by a viewing application ,such as a Web browser.
ILEC – Incumbent Local Exchange CarrierThis term was created as a result of the Telecommunications Act of 1996 to differentiate between the established local phone company and a new entrant into the market, which is known as a competitive local exchange carrier (CLEC).
ISDN – Integrated Services Digital NetworkThis is a data service that transmits digital information over a copper line at 128 kilobits a second. It is 10 times faster than a 28.8 modem, which makes it adequate for retrieving text and some graphics and video from the Internet.
IVR – Interactive Voice ResponseThe telephone keypad substitutes for the computer keyboard, allowing anyone with a touch-tone telephone to interact with a computer. Instead of displaying information on a computer screen, IVR uses a digitized voice to convey the menu of options to the caller.
IEC/IXC – Interexchange CarrierThis term technically applies to carriers that provide telephone service between LECs and ATAs. Long-distance companies such as AT&T, Sprint, and MCI are also known as interexchange carriers.
InterLATACommunication between Local Access Transport Areas.
InternationalBetween multiple nations.
InternetThe world’s largest computer network. The Internet originated from a research effort initiated by the U.S. Government and was initially used to connect defense contractors and U.S. universities. Today, its nature is more commercial, and it is becoming the preferred method of linking businesses and individuals’ computers to one another.
InterstateBetween multiple states. Interstate communications are regulated by the FCC.
IntraLATACommunication within a Local Access Transport Area. 1982 MFJ allows LEC to handle these calls without an IEC.
IntranetA local network, for example, an office network, where there are internal web servers accessible to computers in the office, but not accessible from outside the company. Many Intranets are protected from exterior access by various security devices, like firewalls.
IntrastateCommunication within a single state. Intrastate communications are regulated by each state’s PUC.
IP AddressAn IP address is a unique, 32-bit number for a specific TCP/IP host on the Internet. IP addresses are normally written in dotted decimal form such as A host uses a fixed IP Address as identification by all other equipment in the Network.
I SDN – Integrated Service Digital NetworkProvides transmission over copper wire at rates up to 144 kbps. It is a digital line, designed to support data transmission and is divided into three logical channels: 2 B channels that carry your voice, data, and video information and one D channel that carries signaling information. Although this is several times faster than voice band modem, installation costs are relatively high.
ISP – Internet Service ProviderA telecommunications company that provides subscriber access to the Internet. These are the organizations from whom you get Internet access based on Covad DSL. They are also the organizations that provide you with support for your Covad DSL connection – before, during and after we set-up the service at your location. Covad works closely with more than 350 ISPs across the nation to ensure that your fast, “always on” DSL connection runs smoothly.
IXC1) Interexchange Carrier (IEC is preferred). A company providing long-distance phone service between LECs and LATAs.

2) Interexchange Circuit. A circuit that connects PoPs.

IXC Miles – Interexchange Carrier (Long Distance) MilesOn a Price Quote, the coordinates of Location A and Location B are used to calculate mileage-dependent line charges.
Kbps – Kilobits per secondA measure of bandwidth capacity or transmission speed represents a thousand bits per second.
Key SystemKey systems are on-site telephone systems geared to organizations with under 100 telephones. Like PBXs, they switch calls to and from the public network and within users’ premises.
LAN – Local Area NetworkA data communications network covering a small area, usually within the confines of a building or floors within a building. Common LAN protocols are Ethernet and Token Ring.
Last mileThe last connection from the central office to the customer’s home or business over which data or voice flows.
LATALocal Access Transport Areas (200 in the U.S. ). At divestiture in 1984, LATAs were set up as the geographic areas in which Bell telephone companies were allowed to sell local telephone services. LATAs cover metropolitan statistical areas based on population sizes. The RBOCs (baby Bells) and GTE are restricted to operations within, but not between, LATAs. Long distance service within a LATA is provided by the LEC.
LOA – Letter Of AgencyA document that authorizes changing the service provider. (See RespOrg, 800 Portability)
Local AccessThe connection from a subscriber to the Central Office. The portion of a circuit connecting the LEC’s CO with the customer’s premise equipment across the local network.
Local Access ProviderAny organization that is authorized to provide local access. May be the LEC (Local Exchange Carrier) or a CLEC (Competitive Local Exchange Carrier).
LAN – Local Area NetworkA local area network is located on an individual organization’s premise. It enables computer devices such as personal computers, printers, alarm systems and scanners to communicate with each other.
LEC – Local Exchange CarrierThe local or regional telephone company that owns and operates lines to customer locations and Class 5 Central Office Switches. LECs have connections to other COs , Tandem (Class 4 Toll) offices and may connect directly to IECs like Worldcom, AT&T, etc.
LIDB – Line Information Database

Provided by Telcordia (formerly Bellcore) to manage the North American numbering plan (NANP) database

LNP – Local Number Portability

Allows local phone number to be moved between phone companies without changing the number

Local Exchange ServiceLocal phone calls.
Local loopA generic term for the connection between the customer’s premises (home, office, etc.) and the provider’s serving central office. Historically, this has been a wire connection; however, wireless options are increasingly available for local loop capacity.
Long Distance CarrierA company providing long-distance phone service between LECs and LATAs.
Mbps (Megabits per second )A measure of bandwidth capacity or transmission speed. It represents a million bits per second.
Message Toll Service – MTSPay-by-the-minute switched long distance services. Includes conventional long distance and measured WATS.
MOD – ModemMOdulator/DEModulator. Equipment that converts digital signals to analog signals and vice versa. Modems are used to send data signals (digital) over the telephone network, which is usually analog.
MUX – MultiplexerA device that can send several signals over a single line. They are then separated by a similar device at the other end of the link.
NIC – Network Interface CardThe circuit board or other form of computer hardware that serves as the interface between a computer (or other form of data terminal equipment) and the communications network; in DSL, a common NIC is an Ethernet NIC, which serves as the interface to the DSL modem from the computer.
NPA – Area Codes, NXX – Exchanges and XXXX – Line Numbers The process for assigning 10-digit (3+3+4) North American telephone numbers.
Off HookThe signal that the telephone receiver has been lifted (activated). Originating off hook activates a dial tone on switched networks. Destination off hook completes a call (and activates minute-by-minute billing for long distance calls).
One Plus – 1+Customer ability to access the long distance service provider of their choice by first dialing 1, then the long distance number. Equal Access guaranteed by the 1982 AT&T MFJ. 1+ is an outbound service where the calling station pays the charges.
OSP – Operator Service ProviderProvides Operator Services (0+) on a state or national basis.
OSS – Operational Support System

Allows carriers to communicate electronically between facilities and order entry systems.

Packet SwitchingA switching system that uses a physical communications connection only long enough to transit a data message; data messages are disassembled into packets and reassembled at the receiving end of the communication link; packets may travel over many diverse communications links to get to the common endpoint. This is most often contrasted with circuit switching in data communications, where all data messages transmitted during a session are transmitted over the same path for the duration of the session.
PBX – Private Branch ExchangeA subscriber-owned telecommunications exchange that usually includes access to the public switched network.
PDF – Portable Document Format

The Page description language used in the Acrobat document exchange system. De facto standard for on-line publishing.

Person-to-PersonOperator assisted phone call – only billed if the specified person is available.
PIC – Primary Interexchange CarrierThe IEC that 1+ calls are routed to. Specified by ANI.
PIC ChargesA LEC charge for changing the PIC. Often paid by the new IEC. If a LEC sends a PIC charge to a customer, the new IEC will typically credit the customer’s account.
PIC FreezeA PIC Freeze prevents the long distance from being switched for the specified ANIs. Useful to prevent slamming, or the unauthorized switching of long distance services.
PIC RequestA request record sent to a LEC asking for an ANI to be activated, deactivated or changed in some way.
PIC ResponseA response record sent by a LEC (corresponding to a previous PIC Request) with a response code that indicates whether the request was performed. (Some LECs return non-standard PIC Response codes.)
PICCNational Access Fee, Pre-subscribed Interexchange Carrier Charge, Pre-subscribed Line Charge, Regulatory Related Charge, or Carrier Line Charge. Pronounced “pixie.” This charge started on January 1, 1998 as part of the FCC overhaul of telephone fees. Long distance companies pay a flat fee to the local telephone company when you pre-subscribe your telephone line to their long distance service. (Sometimes referred to “Dial 1” or “Plus 1” service) The charge is designed to compensate the local telephone companies for the costs associated with providing “local loop” service.
POP – Point Of PresenceThe physical access location interface between a local exchange carrier and an Interexchange Carrier fiber network. The point to which the telephone company terminates a subscriber’s circuit for long distance service or leased line communications.
Point-To-PointNon-switched, dedicated communication circuit.
POSA – Point of Sale Application

This includes ATM, cellular and prepaid card terminals

POTSPlain Old Telephone Service.
PRI – Primary Rate InterfaceAccess to the public switched telephone network at 2Mbits.
Primary Interexchange CarrierThe long distance company that is automatically accessed when a customer dials 1+.
Private LineUses dedicated circuits to connect customer’s equipment at both ends of the line. Does not provide any switching capability (unless supported by customer premise equipment). Usually includes two local loops and an IEC circuit.
ProvisioningThe process by which a requested (ordered) service is designed, implemented and tracked.
PSN – Packet Switched NetworkA network that does not establish a dedicated path through the network for the duration of a session but, instead, transmits data in units called packets in a connectionless manner. Data streams are broken into packets at the front end of a transmission, sent over the best available network connection, and then reassembled in their original order at the destination endpoint
PSP – Payphone Service Provider

Provider of payphone services

PSTN – Public Switched Telephone NetworkA circuit-switched analogue network that makes connections for the duration of telephone call. These connections are usually used for voice but can also carry data between facsimile machines and computers (via a modem).
PUC – Public Utilities CommissionThe agency regulating intrastate phone service.
Rate ElementA recurring fixed charge for IEC or LEC service at the lowest level. A local loop may have multiple rate elements associated with it, which make up the fixed portion of the monthly bill. For example: Local Access, Local Mileage, Entrance facilities, Channel Termination, Interexchange, etc.
RBOC – Regional Bell Operating CompaniesOne of the seven “Baby Bell” Companies created by the 1982 Modified Final Judgement that specified the terms of the AT&T Divestiture. The seven RHCs include: NYNEX, Bell Atlantic, Bell South, Southwestern Bell , U.S. West, Pacific Telesis, and Ameritech. “RBOC” is sometimes used informally to refer to the Regional Holding Companies defined in the 1982 MFJ. (See Bell Operating Companies – There are 19 BOCs).
RegulatorsFCC, PUC, Federal Courts (e.g. MFJ), etc.
R/O or RespOrg – Responsible OrganizationWith 800 Portability, the Number Administration Service Center (NASC) allows the RespOrg to make changes such as carrier, termination, 800 call routing (by time of day, location.) A Letter Of Agency (LOA) must be on file to change the RespOrg for each customer/account.
RouterA router is used to connect two or more dissimilar networks together which may be LANs, WANs, or a mixture of both.
SDSL Symmetrical Digital Subscriber Line. A symmetrical member of the DSL family that supports data speeds from 192 Kbps to 1.5 Mbps in both directions.
SlamAn end user that is PICed without their permission. An RBOC Slam Fee must be paid for each slam.
SONET – Synchronous Optical Network

A fiber-optic transmission system for high speed digital traffic. Sonet speeds range from 51 Mbps to multiple Gigabits per second. It uses a self-healing architecture that is able to reroute traffic if the line goes down.

Speed DialingA service to abbreviate and accelerate frequently dialed numbers.
SS7 – Signalling System 7

A call routing protocol allowing for “look ahead” routing to send a call via the least congested route on the network

State TaxA collection of tax types that each state is allowed to charge. Tax jurisdiction (which state can charge tax for a call) is based on the two-out-of-three rule: where it originates, where it terminates, where it is being billed to – if two match , that state can charge the tax.
Static IPAn address on your network that never changes. Static IP Addresses are obtained from ISPs.
SurchargeAn additional charge on top of a base rate for a specified reason.
Switched AccessNondedicated local access between the customer’s premise and the serving wire center which is interconnected to the company’s point-of-presence for origination or termination of service.
Switched Access ServiceA class of LEC services that provides the link from the customer’s premise to the IEC PoP for switched circuits.
Switched ServicesAll dial up long-distance services including conventional residential and WATS (most have incremental use charges). (See Message Toll Service)
Switching FeeA per-line fee (usually around 5$) imposed by the LEC to reprogram their switching system to change your default carrier. Subscribers must usually pay this fee when switching to a reseller. Some resellers will reimburse the subscribers for this fee.
T1 / DS-1(Facility) The equivalent of 24 multiplexed voice grade channels. 1.544 million bits per second (1.5Mbps)
T 2/DS-2 (Facility) The equivalent of 4 multiplexed T1 channels. 6.312 million bits per second (6.3Mbps)
T3/DS-3(Facility) The equivalent of 28 multiplexed T1 channels. 44.736 million bits per second (45Mbps)
TariffA public document filed with the FCC or a PUC that outlines services and rates. Usually, all customers are offered the same rate for a specific service, based on published constraints.
TCP/IP (Transmission Control Protocol/Internet Protocol ) The TCP/IP is a networking protocol that provides communication across interconnected networks, between computers with diverse hardware architectures and various operating systems. TCP (Transmission Control Protocol) and IP (Internet Protocol) are only two protocols in the family of Internet protocols. Over time, however, “TCP/IP” has been used in industry to denote the family of common Internet protocols.
TDDTelecommunications Device for the Deaf
Telco – Telephone Company The local or regional telephone company that owns and operates lines to customer locations and Class 5 Central Office Switches.
Time of Day RoutingRoute calls based on the time the call originates. ( e.g . direct morning calls to East Coast operators and afternoon calls to West Coast operators, etc.). SMS/800 supports 15 minute time intervals.
Toll CallA call with incremental use (minute-by-minute) charges.
Toll FraudA crime in which a “hacker” obtains telecommunication services by: breaching computer security, using or selling stolen long-distance credit-card codes, or, accessing a PBX and using its communication facilities illegally. Toll Fraud is estimated to cost U.S. companies $1.2 billion/year.
Two-Out-Of-Three RuleWhen determining state tax jurisdiction, there are three locations to consider: originating station, destination station, and the location that the bill is sent to. If two out of three are the same, then that state receives the tax.
UNEUnbundled network element is the term used to describe how companies like Covad would order services from the phone companies under line sharing. Covad only wants to lease a portion of the line to use for data, not the whole line. Thus, unbundling the network elements enables Covad to buy the portion we want and let the phone companies utilize the rest.
UpstreamIn DSL, the communications from the customer site up into the telecommunications network.
URL – Uniform Resource LocatorA text-based address used to identify specific resources on the Internet, such as web pages. URLs are arranged in a hierarchical form that specifies the name of the server on which a resource is located (such as and the name of the file on that server (
USF – Universal Service Fund Charge or Universal Service ChargeThis charge started on January 1, 1998 as part of the FCC overhaul of telephone fees. All companies that provide telephone service between states pay a set percentage of their previous year’s billings. The charge is designed to ensure affordable access to telecommunications services for telephone customers with low incomes, telephone customers who live in areas where the cost of providing telephone service is extremely high, libraries, schools, and rural health care providers.
VAD – Virtual Access Device/Distributor

An enhanced multiplexer or VAR-type distribution company

Vanity NumberA specific 800 or 888 number. Some may spell a word or name.
Verified Account CodesSee Account Codes. A finite list of carrier-verified, predefined Account Codes.
VPN – Virtual Private NetworkVirtual Private Networks offer the illusion of a private network when in fact the public ISDN network is being used. This means that all of the advantages of a private network can be enjoyed, but at a fraction of the cost.
Voice MailAn automatic answering service with the ability to record a message. Unlike simple answering machines, Voice mail uses a programmable computer system with options such as temporary call routing, monitoring and reporting, etc.
Voice Mail BoxThe assignment of one user/number on a voice mail system.
VoIP – Voice over IP Voice information is sent in digital form in discrete packets over the Internet instead of in analog form over the public switched network.
WAN – Wide Area Network

The network that connects physically separate facilities across network boundaries outside of the firewall. The WCS service is considered as toll wide area network services connecting multiple LANs or personnel.

WAP – Wireless Application Protocol

Handheld and wireless device service protocol allowing integration with web database core applications.

WATS – Wide Area Telephone ServiceFlat rate, or special rate pay-by-the-minute (measured) billing for a specified calling area. May be outbound or inbound (e.g. 800).
Web ServerA Web server is a program that allows Web browsers to retrieve files from computers connected to the Internet. The Web server listens for requests from Web browsers and when it receives a request it finds the file and sends it back to the browser. The primary function of a Web server is to serve pages to other remote computers, and so it needs to be on a computer that is connected to the Internet full-time.
WWW – World Wide WebThe World Wide Web is often thought to be synonymous with the Internet, but this is not so. It is essentially a user-friendly interface which rides on top of the Internet so as to present the user with the full range of the Internet’s resources but without the hassle of ploughing through reams of complicated procedures.
WTN Working Telephone Number.

The generic term for the suite of digital subscriber line (DSL) services, where the “x” can be replaced with any of the letters that represent one of the various types of DSL technology (ADSL, HDSL, IDSL, MDSL, RADSL, SDSL, VoDSL).