IVR is a technology that automates interactions with telephone callers. Enterprises are increasingly turning to IVR to reduce the cost of common service, collections, inquiry and support calls for their company.
IVR system can help to direct customers to the right support they need.(e.g.: Press 1 for sales, Press 2 for promos, Press 3 to talk to an executive, etc.)
Below dialgram shows how IVR works on multiple line of telco like E1/T1, PRI Line or GSM gateway. IVRs sytem can also work with SIP based DID number having sip credentials.