Direct Inward Dialing

A DID (Direct Inward Dialing) is a telephone number that routes incoming calls directly into a VICIdial system without requiring a receptionist or operator. DIDs are the inbound phone numbers that customers call, and VICIdial uses them to route calls to specific inbound groups, call menus (IVRs), or directly to agents.

How It Works in VICIdial

DIDs are configured in the VICIdial admin panel under the Inbound DID section. Each DID entry maps a phone number to a routing destination — typically an inbound group, IVR/call menu, or a specific agent extension. When a call arrives on a DID, VICIdial matches the dialed number against its DID table and routes accordingly.

DIDs can be provisioned from carriers as local, toll-free, or international numbers. They are delivered to VICIdial over SIP trunks, and the system identifies the DID from the SIP headers (specifically the To or DNIS field). VICIdial supports thousands of DIDs per server, each with independent routing rules including time-of-day routing, holiday schedules, and failover destinations.

DIDs also serve as the return number for outbound campaigns — when a lead calls back a missed call, the DID routes them to the appropriate inbound group associated with the outbound campaign.

Why It Matters

Proper DID management is critical for both inbound call centers and outbound campaigns that generate callbacks. Each DID represents a customer touchpoint and must be correctly routed to avoid lost calls. For outbound campaigns, using local DIDs matching the area codes being dialed (local presence) significantly improves answer rates and contact rates.

VICIdial’s DID routing flexibility supports complex call flows with multiple tiers of failover. For DID management strategies, see our DID management guide and the DID hygiene feature page.