Campaign Hold Queue

What the Hold Queue Does

When a call arrives at an offer and no buyer is immediately available, the offer can park the caller in a hold queue rather than rejecting or voice-mailing the call. The hold queue plays hold audio, periodically re-checks buyer availability, and delivers the caller to the first buyer that opens up.

Hold Queue Configuration

The hold queue is a dedicated record tied to Campaign. It is not a stateless process -- it persists configuration and enforces limits in real time.

Each hold queue configuration settings (maximum callers, percentage-based sizing, max hold seconds, and average-wait limit) all live on the call router. The hold queue reads those settings and enforces them at runtime.

Trigger: Add To Hold Queue

The "add to hold queue" router fires during the routing decision when no buyer is immediately available. The system parks the call, starts the hold audio, marks the call with a status of "on-hold" and records when it entered the queue. It then begins periodically re-running buyer selection to find an available buyer.

Trigger: Hold Queue Max Seconds Exceeded

The "When the caller has been on hold for longer than max hold seconds" router fires when a caller has been parked longer than the configured maximum. The system looks up the router, runs any configured webhook actions, and redirects the caller to the configured call flow. If no fallback router exists, the call is hung up with a reason.

Trigger: Hold Queue Is Full

When placing a call on hold, the system checks the caller limit first, then the percentage-based size (a percent of the offer's total active concurrency cap), then the average hold time across recent held calls. If any limit is exceeded, the call is not added to the queue and the "hold queue is full" router's action determines the next step.

Queue Size Calculation

The effective queue size cap is determined in priority order:

1. The absolute caller limit if configured, otherwise
2. A percentage of the offer's total active concurrency cap if a percentage size is configured, otherwise
3. 20 percent of the offer's total active concurrency cap (default).