An automatic number announcement circuit (ANAC) is a component of a central office of a

telephone company A telecommunications company is a kind of electronic communications service provider, more precisely a telecommunications service provider (TSP), that provides telecommunications services such as telephony and data communications access. Many t ...

that provides a service to installation and service technicians to determine the

telephone number A telephone number is the address of a Telecommunications, telecommunication endpoint, such as a telephone, in a telephone network, such as the public switched telephone network (PSTN). A telephone number typically consists of a Number, sequ ...

of a

telephone line A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or oth ...

. The facility has a telephone number that may be called to listen to an automatic announcement that includes the caller's telephone number. The ANAC facility is useful primarily during the installation of

landline A landline is a physical telephone connection that uses metal wires or optical fiber from the subscriber's premises to the network, allowing multiple phones to operate simultaneously on the same phone number. It is also referred to as plain old ...

telephones to quickly identify one of multiple wire pairs in a bundle or at a termination point.

Operation

By connecting a test telephone set, a technician calls the local telephone number of the automatic number announcement service. This call is connected to equipment at the central office that uses automatic equipment to announce the telephone number of the line calling in. The main purpose of this system is to allow telephone company technicians to identify the telephone line they are connected to. Automatic number announcement systems are based on

automatic number identification Automatic number identification (ANI) is a feature of a telecommunications network for automatically determining the origination telephone number on toll calls for billing purposes. Automatic number identification was originally created by the Am ...

. They are intended for use by phone company technicians, the ANAC system bypasses customer features, such as unlisted numbers, caller ID blocking, and outgoing call blocking. Installers of multi-line business services where outgoing calls from all lines display the company's main number on call display can use ANAC to identify a specific line in the system, even if CID displays every line as "line one". Most ANAC systems are provider-specific in each wire center, while others are regional or state-/province- or area-code-wide. No official lists of ANAC numbers are published, as telephone companies guard against abuse that would interfere with availability for installers.

Exchange prefixes for testing

The

North American Numbering Plan The North American Numbering Plan (NANP) is an integrated telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1, World Numbering Zone ...

reserves the exchange (''central office'') prefixes ''958'' and ''959'' for plant testing purposes. Code 959 with three or four additional digits is dedicated for access to office test lines in

local exchange carrier Local exchange carrier (LEC) is a regulatory term in telecommunications for the local telephone company. In the United States, wireline telephone companies are divided into two large categories: long-distance ( interexchange carrier, or IXCs) ...

and interoffice carrier central offices. The specifications define several test features for line conditions, such as quiet line and busy line, and test tones transmitted to callers. Telephone numbers are assigned for ring back to test the ringer when installing

telephone A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most ...

sets, milliwatt tone (a number simply answers with a continuous

test tone A test card, also known as a test pattern or start-up/closedown test, is a television test signal, typically broadcast at times when the transmitter is active but no program is being broadcast (often at sign-on and sign-off). Used since the ear ...

) and a loop around (which connects a call to another inbound call to the same or another test number). ANAC services are typically installed in the ''958'' range, which is intended for communications between central offices. In some area codes, multiple additional prefixes may be reserved for test purposes. Many area codes reserved 999; 320 was also formerly reserved in

Bell Canada Bell Canada (commonly referred to as Bell) is a Canadian telecommunications company headquartered at 1 Carrefour Alexander-Graham-Bell in the borough of Verdun, Quebec, in Canada. It is an ILEC (incumbent local exchange carrier) in the province ...

territory. Other carrier-specific North American test numbers include 555-XXXX numbers (such as 555–0311 on

Rogers Communications Rogers Communications Inc. is a Canadian communications and media company operating primarily in the fields of wireless communications, cable television, telephony and Internet, with significant additional telecommunications and mass media ass ...

in Canada) or

vertical service code A vertical service code (VSC) is a sequence of digits and the signals star () and pound/hash () dialed on a telephone keypad or rotary dial to access certain telephone service features. Some vertical service codes require dialing of a telephone ...

s, such as *99 on Cablevision/Optimum Voice in the United States.

MCI Inc. MCI, Inc. (formerly WorldCom and MCI WorldCom) was a telecommunications company. For a time, it was the second-largest long-distance telephone company in the United States, after AT&T. WorldCom grew largely by acquiring other telecommunicatio ...

(United States) provides ANI information by dialing 800-444-4444.

Telephone numbers

Plant testing telephone numbers are carrier-specific, there is no comprehensive list of telephone numbers for ANAC services. In some communities, test numbers change relatively often. In others, a major incumbent carrier might assign a single number which provides test functions on its network across an entire numbering plan area, throughout an entire province or state, or system-wide. Some telecommunication carriers maintain

toll-free number A toll-free telephone number or freephone number is a telephone number that is billed for all arriving calls. For the calling party, a call to a toll-free number is free of charge, unless air-charges apply for mobile telephone service. A toll-free ...

s for ANAC facilities. Some national toll-free numbers provide

by speaking the telephone number of the caller, but these are not intended for use in identifying the customer's own phone number. They are used for the agent in a

call center A call centre (English in the Commonwealth of Nations, Commonwealth spelling) or call center (American English, American spelling; American and British English spelling differences#-re, -er, see spelling differences) is a managed capability th ...

to confirm the telephone a customer is calling from, so that the customer's account information can be displayed as a "

screen pop Screen pop is a call centre term that refers to the feature of a computer telephony integration (CTI) which automatically displays customer information via a window or dialog box on an agent's computer upon answering a customer's call. For ''inb ...

" for the next available

customer service Customer service is the assistance and advice provided by a company to those who buy or use its products or services, either in person or remotely. Customer service is often practiced in a way that reflects the strategies and values of a firm, and ...

representative.

References

{{DEFAULTSORT:Automatic Number Announcement Circuit Telephone numbers Telephony signals

Operation

Exchange prefixes for testing

Telephone numbers

See also

References