Editing Automatic number identification

{{Short description|Feature of a telecommunications network}}
{{use American English|date=October 2022}}
{{use MDY dates|date=October 2022}}
'''Automatic number identification''' ('''ANI''')<ref name=ForF1992NYT>{{cite news |newspaper=[[The New York Times]]
   |url=https://www.nytimes.com/1992/04/04/news/caller-id-consumer-s-friend-or-foe.html
   |title=Caller ID: Consumer's Friend or Foe?
   |author=Anthony Ramirez |date=April 4, 1992  |access-date=September 21, 2022}}</ref><ref name=911PizzaNYT>{{cite news |newspaper=[[The New York Times]]
|url=https://www.nytimes.com/1991/09/09/business/the-pizza-version-of-dialing-911.html
|title=The Pizza Version of Dialing '911'
|date=September 9, 1991}}</ref> 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 [[American Telephone and Telegraph Company]] (AT&T) for [[long distance calling|long distance]] service in the [[Bell System]],<ref>[http://www.freepatentsonline.com/2265844.html US Patent 2,265,844: Calling Line Identification Circuit]</ref><ref>[http://www.freepatentsonline.com/2300829.html US Patent 2,300,829: Calling Line Identification System]</ref> eliminating the need for telephone operators to manually record calls.

Modern ANI has two components: information digits, which identify the class of service,<ref>{{cite web |url=http://www.nanpa.com/number_resource_info/ani_ii_assignments.html|title=ANI II Digits|publisher=[[North American Numbering Plan Administration]]|year=2003|accessdate=2007-07-06| archiveurl= https://web.archive.org/web/20070618024913/http://nanpa.com/number_resource_info/ani_ii_assignments.html| archivedate= 18 June 2007 | url-status= live}}</ref> and the [[calling party]] billing telephone number.

The term is also used to describe the functions of [[two-way radio]] [[selective calling]] that identify the transmitting user.

ANI is distinct from newer [[caller ID]] services, such as call display, which are solely for informing a subscriber.

==Toll-free telephone numbers==
Modern [[toll-free telephone number]]s, which generate itemized billing of all calls received instead of relying on the special fixed-rate trunks of the [[Bell System]]'s original [[Wide Area Telephone Service|Inward WATS]] service, depend on ANI to track inbound calls to numbers in special [[area code]]s such as +1-800, 888, 877, 866, 855, 844, and 833 with 822 reserved for future toll free use (United States and Canada), 1800 (Australia) or 0800 and 0808 (United Kingdom).

==Privacy==
ANI is conceptually and technically different from caller ID service.<ref name=ForF1992NYT/> A caller's telephone number and line type are captured by ANI service even if [[Caller ID#Blocking|caller ID blocking]] is activated. The destination telephone company switching office can relay the originating telephone number to ANI delivery services subscribers. Toll-free subscribers and large companies normally have access to ANI, either instantly via installed equipment, or from a monthly billing statement. Residential subscribers can obtain access to ANI information through third party companies that charge for the service.<ref>{{cite web |title=TrapCall Displays Blocked Numbers on Your Caller ID |url=https://gizmodo.com/5155206/trapcall-displays-blocked-numbers-on-your-caller-id |first=Sean |last=Fallon |website=Gizmodo |date=2009-02-17 |access-date=2021-06-26 }}</ref>

ANI is generally not transmitted when a call is operator assisted; only the area code of the last switch to route the call is sent.{{cn|date=November 2022}}

==Automatic number announcement==
ANI is used to provide [[Automatic number announcement circuit|automatic number announcement]], a test facility of a central office for telephone installation technicians. The service, which is not advertised to the public, allows an installer to identify a line by dialing a telephone number. Such numbers are typically assigned in a [[plant test number|a range reserved for testing purposes]] (such as 958-xxxx in much of North America).

==DNIS==
[[Dialed Number Identification Service]] (DNIS) is a related service feature available to [[private branch exchange]] subscribers.<ref>{{cite book
   |title=Encyclopedia of Information Technology |date=2007
   |publisher=Atlantic Publishers and Distributors LTD|isbn=978-81-269-0752-6|page=142}}</ref><ref>[https://books.google.com/books?id=pyguvxndiogC&pg=PA315&lpg=PA315&dq=at%26t+dnis&source=bl&ots=dRVcDwKkRz&sig=Wk3_lj9i68Ur63tUpk_Np28uM94&hl=en&ei=rSAKS8_jNdKWtge20ryzCg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CA8Q6AEwAjge#v=onepage&q=at%26t%20dnis&f=false>Waite, Andrew]. A Practical Guide to Call Center Technology. p315. {{Webarchive|url=https://web.archive.org/web/20140628160252/http://books.google.com/books?id=pyguvxndiogC&pg=PA315&lpg=PA315&dq=at%26t+dnis&source=bl&ots=dRVcDwKkRz&sig=Wk3_lj9i68Ur63tUpk_Np28uM94&hl=en&ei=rSAKS8_jNdKWtge20ryzCg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CA8Q6AEwAjge#v=onepage&q=at%26t%20dnis&f=false>Waite, |date=2014-06-28 }}</ref> It transmits information about the destination number, which a service provider can use to have several toll-free numbers directed to the same [[call center]] and provide unique service. DNIS can also be used to identify other call routing information. For example, toll-free service can be configured to send a specific DNIS number that is assigned to callers from geographic regions based on city, area code, state, or country.

==Similar services==
* Europe: [[Calling Line Identification]] (CLI)
* [[United Kingdom]]: [[Caller Line Identification]] (CLID)
* [[Australia]]: Automatic number identification (ANI) 1800801920 or 12722123 (Telstra line only, local call cost)

==References==
{{Reflist}}

{{Telecommunications}}

[[Category:Anonymity]]
[[Category:Telephony signals]]