Invalid ANI Ratio

IAR is the measure of invalid ANI values within a dataset. For example, if a customer made 1,000 call attempts and 100 had invalid ANIs then their IAR would be 10%. Whether or not an ANI is valid is done by comparing the ANI to the LERG to validate the NPA and NXX. People using random numbers will often simply use a function to create a random number between 1,000,000,000 and 9,999,999,999 but will never actually check to make sure the NPA and NXX of the random number are valid.

Statistically, if someone is using a random number generator then ~13% of the ANIs generated will be invalid. If you have an account or media IP with high ACR and IAR then you can feel confident that the customer is up to no good. We recommend investigating immediately.