Telephone Identification

Telephone identifcation is the process of determining the type of phone being used by a consumer or end user. This technique looks up the phone number to determine where it was provisioned, and the type of phone it is associated with.
Telephone identification, or TNI, serves several important functions. First it authenticates that the number is a real "dialable" phone number. Second it will let you know where the phone was provisioned, the country, region, and city. Lastly, and most importantly it will tell you the type of phone the number is assigned to.

To read more on Device Identification: http://www.fraudpractice.com/gl-phoneID.html