Answer Signal: when an inbound call is marked answered

When a phone call connects, somebody has to say it was answered. That moment is the answer signal: the point where your system tells the upstream Carrier the call is now live. It matters because most carriers start billing from the answer, and because audio prompts and hold music behave differently before and after that signal.

On an inbound group you control this with the Answer Signal setting. A DID (direct inward dialing) hands the call to the Ingroup, and from there the answer signal decides exactly when the caller stops hearing a ring and starts hearing your queue.

The three choices

• START: the answer signal is sent the instant the call arrives in the in-group. The caller hears your welcome message and hold music right away.
• ROUTE: the answer signal is held back until the call is routed away from the in-group, for example to an agent.
• NONE: no answer signal is sent at all, which you would only use in narrow cases where something downstream answers the call.

The default is START, and for most inbound queues that is what you want. The caller needs to hear your prompts and music while they wait, and prompts cannot play to a call that has not been answered.

Why ROUTE exists

Some teams want the carrier billing clock to start only when a real agent picks up, not while the caller is still in the queue. ROUTE delays the answer until the call leaves the queue. The trade-off is that callers waiting in line may not get full in-queue audio the same way, so test it before you commit. For most people the cleaner choice is START plus a sensible hold experience.

Where the signal fires

sequenceDiagram
  participant C as Carrier
  participant D as DID
  participant I as Ingroup
  participant A as Agent
  C->>D: Inbound call
  D->>I: Hand to queue
  Note over I: START answers here
  I->>A: Route to agent
  Note over A: ROUTE answers here
  A-->>C: Two way audio

Answer timing is one piece of the larger inbound flow. To see how DIDs, queues, agents and prompts fit together, read the inbound call handling guide. If you have not built your queue yet, our walkthrough on adding an inbound group is the place to start.

Getting answer signals, SIP (Session Initiation Protocol) trunks and carrier billing to line up is fiddly when you wire it by hand. Our managed VICIdial hosting ships a working dialplan in under a minute, so you only need to pick START or ROUTE and move on.