What is ANI / Caller ID spoofing?
ANI / Caller ID spoofing is setting the ANI / Caller ID on the outgoing call you are making to a 10 digit number of your own choosing. Traditionally it has been a complicated process either requiring the assistance of a cooperative phone company operator or an expensive company PBX system. . . .
What is Caller ID?
Caller ID is a service provided by most telephone companies (for a monthly cost) which will tell you the number / name of an incoming call. [Definition: Hack FAQ ]

What is ANI?
Automatic Number Identification is a system used by the telephone company to determine the number of the calling party. There are believed to be two types, "FLEX ANI" (used for e.g. verification services such as voicemail) which is relatively easy to spoof, and "Real Time ANI" (used only for billing purposes on e.g. 800 numbers) which is harder to spoof. [Definition: Hack FAQ ]

What is ANI / Caller ID spoofing?
ANI / Caller ID spoofing is setting the ANI / Caller ID on the outgoing call you are making to a 10 digit number of your own choosing. Traditionally it has been a complicated process either requiring the assistance of a cooperative phone company operator or an expensive company PBX system.

What is Automated ANI / Caller ID spoofing?
Automated ANI / Caller ID spoofing is setting the number you are calling from without the use of an operator / company PBX system. By far the easiest method thanks to the increasing take-up of internet telephony services are VoIP (Voice over Internet Protocol) service providers who allow you when using their service to set whatever caller ID you like (which is also used as ANI).

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