What the Drop Percentage Limit setting does

When you switch a campaign to predictive dialing, you are asking VICIdial to call more lines than you have agents, betting that some of those calls will go to voicemail or ring out. Sometimes that bet is wrong, a live person answers, and there is no agent free to talk to them. That is a dropped call. The Drop Percentage Limit field is where you tell the dialer how much of that you are willing to tolerate, and it is one of the few settings that the dialer actively obeys in real time.

What the number actually means

The figure you enter is a ratio: dropped calls divided by calls a human answered, expressed as a percent. So a setting of 3 means that out of every hundred calls a person picks up, you accept that up to three of them may be abandoned before an agent connects. It is not three percent of all dials, only of the ones that turned into live answers. That distinction matters because answered calls are the only ones that can ever become a nuisance call.

The default value of 3 is not arbitrary. It matches the United States FTC ceiling for the ratio of abandoned to human-answered calls, measured as a rolling 30-day average per campaign for consumer dialing. If you operate under a stricter rule, or you simply want a quieter line, you can lower it. Raising it above what your regulator allows is how operators get into trouble with tcpa and ftc compliance.

How the dialer uses it

When you run an adaptive dialing method, VICIdial watches your live drop rate and compares it to the limit you set. As your measured rate climbs toward the ceiling, the dialer eases off on its own, opening fewer lines per agent so that more answered calls land on someone who can talk. If your rate is comfortably under the limit, it pushes the pace back up to keep agents busy. This is the core feedback loop of predictive dialing: the limit you type here is the line the algorithm steers around.

Because the dialer averages recent performance, it does not snap back the instant your drop rate spikes. Expect fifteen to thirty seconds for it to react to a sudden change in how often leads answer. If you keep blowing past your limit, the limit itself is rarely the problem, the pacing around it is. Our walks through the other knobs that feed into this number.

Where it does not apply

The Drop Percentage Limit only does anything in adaptive-predictive modes. In MANUAL, INBOUND_MAN, or RATIO the field sits there with no effect, because in those modes the dialer is not choosing how aggressively to open lines, you or a fixed multiplier are. There is also a related quirk: an Agent In-Call Tally Seconds Threshold, which lets you stop counting an agent for new calls after they have been talking a while, only works when Available Only Tally is switched off. If you are still tuning your overall approach, the puts this field in context with the rest of the campaign screen.

If you would rather not babysit any of these fields, a managed VICIdial box on ships with sane defaults already in place so you can dial cleanly from day one.