ANI and ANI II Digits

ANI is the number of the caller, and ANI II Digits define the type of caller.

ANI (Automatic Number Identification) 

ANI is simply the method used to identify the number of the caller.  In fact, people will often refer to a caller's number as the ANI.  Technically, ANI is not the number . . . it is the process of identifying the number.  However, it is now so commonly referred to as the number, that the definition of the acronym has changed . . . the ANI is the number transmitted through the network that identifies the calling party.

ANI 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).

 

ANI II Digits  (Automatic Number Identification II Digits)

Automatic Number Identification (ANI) II digits are two-digit pairs sent with the originating telephone number. These digits identify the type of originating station.

There are no assignment guidelines for ANI II digits. Applicants for ANI II digit assignments should approach the Industry Numbering Committee (INC). If the INC reaches consensus that the requested assignment is warranted, it will instruct NANPA to make the assignment.

Here are all the currently assigned ANI II pairs.

 

DIGIT PAIR DESCRIPTION
00 Plain Old Telephone Service (POTS) - non-coin service requiring no special treatment
01 Multiparty line (more than 2) - ANI cannot be provided on 4 or 8 party lines. The presence of this "01" code will cause an Operator Number Identification (ONI) function to be performed at the distant location. The ONI feature routes the call to a CAMA operator or to an Operator Services System (OSS) for determination of the calling number.
02 ANI Failure - the originating switching system indicates (by the "02" code), to the receiving office that the calling station has not been identified. If the receiving switching system routes the call to a CAMA or Operator Services System, the calling number may be verbally obtained and manually recorded. If manual operator identification is not available, the receiving switching system (e.g., an interLATA carrier without operator capabilities) may reject the call.
03-05 Unassigned
06 Station Level Rating - The "06" digit pair is used when the customer has subscribed to a class of service in order to be provided with real time billing information. For example, hotel/motels, served by PBXs, receive detailed billing information, including the calling party’s room number. When the originating switching system does not receive the detailed billing information, e.g., room number, this "06" code allows the call to be routed to an operator or operator services system to obtain complete billing information. The rating and/or billing information is then provided to the service subscriber. This code is used only when the directory number (DN) is not accompanied by an automatic room/account identification.
07 Special Operator Handling Required - calls generated from stations that require further operator or Operator Services System screening are accompanied by the "07" code. The code is used to route the call to an operator or Operator Services System for further screening and to determine if the station has a denied-originating class of service or special routing/billing procedures. If the call is unauthorized, the calling party will be routed to a standard intercept message.
08-09 Unassigned
10 Not assignable - conflict with 10X test code
11 Unassigned
12-19 Not assignable - conflict with international outpulsing code
20 Automatic Identified Outward Dialing (AIOD) - without AIOD, the billing number for a PBX is the same as the PBX Directory Number (DN). With the AIOD feature, the originating line number within the PBX is provided for charging purposes. If the AIOD number is available when ANI is transmitted, code "00" is sent. If not, the PBX DN is sent with ANI code "20". In either case, the AIOD number is included in the AMA record.
21-22 Unassigned
23 Coin or Non-Coin - on calls using database access, e.g., 800, ANI II 23 is used to indicate that the coin/non-coin status of the originating line cannot be positively distinguished for ANI purposes by the SSP. The ANI II pair 23 is substituted for the II pairs which would otherwise indicate that the non-coin status is known, i.e., 00, or when there is ANI failure.

ANI II 23 may be substituted for a valid 2-digit ANI pair on 0-800 calls. In all other cases, ANI II 23 should not be substituted for a valid 2-digit ANI II pair which is forward to an SSP from an EAEO.

Some of the situations in which the ANI II 23 may be sent:

 

  • Calls from non-conforming end offices (CAMA or LAMA types) with combined coin/non-coin trunk groups.
  • 0-800 Calls
  • Type 1 Cellular Calls
  • Calls from PBX Trunks
  • Calls from Centrex Tie Lines
24 Code 24 identifies a toll free service call that has been translated to a Plain Old Telephone Service (POTS) routable number via the toll free database that originated for any non-pay station. If the received toll free number is not converted to a POTS number, the database returns the received ANI code along with the received toll free number. Thus, Code 24 indicates that this is a toll free service call since that fact can no longer be recognized simply by examining the called address.
25 Code 25 identifies a toll free service call that has been translated to a Plain Old Telephone Service (POTS) routable number via the toll free database that originated from any pay station, including inmate telephone service. Specifically, ANI II digits 27, 29, and 70 will be replaced with Code 25 under the above stated condition.
26 Unassigned
27 Code 27 identifies a line connected to a pay station which uses network provided coin control signaling. II 27 is used to identify this type of pay station line irrespective of whether the pay station is provided by a LEC or a non-LEC. II 27 is transmitted from the originating end office on all calls made from these lines.
28 Unassigned
29 Prison/Inmate Service - the ANI II digit pair 29 is used to designate lines within a confinement/detention facility that are intended for inmate/detainee use and require outward call screening and restriction (e.g., 0+ collect only service). A confinement/detention facility may be defined as including, but not limited to, Federal, State and/or Local prisons, juvenile facilities, immigration and naturalization confinement/detention facilities, etc., which are under the administration of Federal, State, City, County, or other Governmental agencies. Prison/Inmate Service lines will be identified by the customer requesting such call screening and restriction. In those cases where private paystations are located in confinement/detention facilities, and the same call restrictions applicable to Prison/Inmate Service required, the ANI II digit for Prison/Inmate Service will apply if the line is identified for Prison/Inmate Service by the customer.
30-32 Intercept - where the capability is provide to route intercept calls (either directly or after an announcement recycle) to an access tandem with an associated Telco Operator Services System, the following ANI codes should be used:

 

  • 30 Intercept (blank) - for calls to unassigned directory number (DN)
  • 31 Intercept (trouble) - for calls to directory numbers (DN) that have been manually placed in trouble-busy state by Telco personnel
  • 32 Intercept (regular) - for calls to recently changed or disconnected numbers
33 Unassigned
34 Telco Operator Handled Call - after the Telco Operator Services System has handled a call for an IC, it may change the standard ANI digits to "34", before outpulsing the sequence to the IC, when the Telco performs all call handling functions, e.g., billing. The code tells the IC that the BOC has performed billing on the call and the IC only has to complete the call.
35-39 Unassigned
40-49 Unrestricted Use - locally determined by carrier
50-51 Unassigned
52 Outward Wide Area Telecommunications Service (OUTWATS) - this service allows customers to make calls to a certain zone(s) or band(s) on a direct dialed basis for a flat monthly charge or for a charge based on accumulated usage. OUTWATS lines can dial station-to-station calls directly to points within the selected band(s) or zone(s). The LEC performs a screening function to determine the correct charging and routing for OUTWATS calls based on the customer’s class of service and the service area of the call party. When these calls are routed to the interexchange carrier via a combined WATS-POTS trunk group, it is necessary to identify the WATS calls with the ANI code "52".
53-59 Unassigned
60 TRS - ANI II digit pair 60 indicates that the associated call is a TRS call delivered to a transport carrier from a TRS Provider and that the call originated from an unrestricted line (i.e., a line for which there are no billing restrictions). Accordingly, if no request for alternate billing is made, the call will be billed to the calling line.
61 Cellular/Wireless PCS (Type 1) - The "61" digit pair is to be forwarded to the interexchange carrier by the local exchange carrier for traffic originating from a cellular/wireless PCS carrier over type 1 trunks. (Note: ANI information accompanying digit pair "61" identifies only the originating cellular/wireless PCS system, not the mobile directory placing the call.
62 Cellular/Wireless PCS (Type 2) - The "62" digit pair is to be forwarded to the interexchange carrier by the cellular/wireless PCS carrier when routing traffic over type 2 trunks through the local exchange carrier access tandem for delivery to the interexchange carrier. (Note: ANI information accompanying digit pair "62" identifies the mobile directory number placing the call but does not necessarily identify the true call point of origin.)
63 Cellular/Wireless PCS (Roaming) - The "63" digit pair is to be forwarded to the interexchange carrier by the cellular/wireless PCS subscriber "roaming" in another cellular/wireless PCS network, over type 2 trunks through the local exchange carrier access tandem for delivery to the interexchange carrier. (Note: Use of "63" signifies that the "called number" is used only for network routing and should not be disclosed to the cellular/wireless PCS subscriber. Also, ANI information accompanying digit pair "63" identifies the mobile directory number forwarding the call but does not necessarily identify the true forwarded-call point of origin.)
64-65 Unassigned
66 TRS - ANI II digit pair 66 indicates that the associated call is a TRS call delivered to a transport carrier from a TRS Provider, and that the call originates from a hotel/motel. The transport carrier can use this indication, along with other information (e.g., whether the call was dialed 1+ or 0+) to determine the appropriate billing arrangement (i.e., bill to room or alternate bill).
67 TRS - ANI II digit pair 67 indicates that the associated call is a TRS call delivered to a transport carrier from a TRS Provider and that the call originated from a restricted line. Accordingly, sent paid calls should not be allowed and additional screening, if available, should be performed to determine the specific restrictions and type of alternate billing permitted.
68-69 Unassigned
70 Code 70 identifies a line connected to a pay station (including both coin and coinless stations) which does not use network provided coin control signaling. II 70 is used to identify this type pay station line irrespective of whether the pay station is provided by a LEC or a non-LEC. II 70 is transmitted from the originating end office on all calls made from these lines.
71-79 Unassigned
80-89 Reserved for Future Expansion "to" 3-digit Code
90-92 Unassigned
93 Access for private virtual network types of service: the ANI code "93" indicates, to the IC, that the originating call is a private virtual network type of service call.
94 Unassigned
95 Unassigned - conflict with Test Codes 958 and 959
96-99 Unassigned