Automatic Number Identification

ANI (Automatic Number Identification) is a telephony service that identifies the phone number of the calling party and delivers it to the receiving system. In VICIdial, ANI provides the caller’s phone number on inbound calls, enabling lead matching, CRM screen pops, routing decisions, and compliance verification. ANI is closely related to but technically distinct from Caller ID (CID) — ANI is a carrier-level service that cannot be blocked by the caller, while CID can be restricted or spoofed.

How It Works in VICIdial

When an inbound call arrives at VICIdial via a SIP trunk, the ANI is carried in the SIP “From” header or P-Asserted-Identity header. Asterisk extracts this number and passes it to VICIdial’s inbound call processing engine. VICIdial uses the ANI to search its lead database for a matching phone number — if found, the lead’s record is displayed on the agent screen when the call is delivered, giving the agent immediate context about who is calling.

ANI-based routing enables VICIdial to make intelligent decisions before the call reaches an agent. For example, the system can check the ANI against the DNC list, look up the caller’s previous interaction history, identify VIP customers for priority routing, or match the caller’s area code to a geographically appropriate agent. ANI is also logged with every call record for reporting, quality assurance, and compliance auditing.

On outbound calls, the concept reverses — VICIdial sets the outbound ANI (the number displayed to the called party) through CID configuration. STIR/SHAKEN attestation validates that the outbound ANI is legitimately associated with the calling party, helping combat caller ID spoofing and improving answer rates.

Why It Matters

ANI is fundamental to inbound call center operations. Without ANI, every inbound call would arrive with no caller identification, forcing agents to manually ask for and look up the caller’s information — adding 15-30 seconds to every interaction and degrading the customer experience. ANI-driven screen pops alone can reduce average handle time by 10-15%.

For outbound operations, ANI integrity is increasingly critical due to STIR/SHAKEN and carrier call-blocking algorithms. Calls with mismatched or unverified ANI information are more likely to be flagged as spam or blocked entirely. Maintaining accurate, verified ANI on outbound calls directly impacts answer rates and campaign effectiveness.