Dialed Number Identification Service (DNIS)
DNIS operates like direct inward dial (DID) or direct inward dialing service, and when used with toll-free lines, it enables the PBX to determine which toll-free number was dialed and to route the call to the proper product agent or manager group. This helps a call center manage multiple programs or companies and identify how to answer the phone for a specific program or client. A feature of 800/900 services that provides the number the caller dialed to the receiving switch. Using DNIS capabilities, one trunk group can be used to serve multiple applications. The DNIS number can be provided in-band or out-of-band, through the Integrated Services Digital Network, or via a separate data channel. In general, a DNIS number will be used to identify to the answering telephone system the “application” the caller dialed.