A campaign is not dialling, or is dialling too slowly
Six causes, ordered by how often they are the answer. Concurrency is usually the one.
A campaign that dials slowly and a campaign that does not dial at all have different causes, so establish which you have by watching the dial attempts number for a few minutes.
Slow is almost always concurrency. Stopped is usually hours, an empty audience, or the campaign being paused. Work through in that order.
Steps
Check the campaign is not paused
Obvious, and worth two seconds before the other five. The status column says Active, Paused or Draft.

Check the calling hours and the timezone
A campaign inherits the channel's restricted call timings. Outside them it will not dial, and it is not supposed to. Check the timezone specifically.
Check concurrency
Allowed calls count, on the channel. A campaign that dials slowly is usually hitting this ceiling — and inbound calls and other campaigns share it.
If dial attempts plateau at a number close to your allowed calls count, that is your answer.
Check the line has outgoing enabled
You cannot dial out on an inbound-only SIP gateway or on a chat channel. Such a channel should not have been selectable, but check the campaign is pointed where you think.
Check the audience is not empty
A dynamic filter on open stages shrinks as terminal outcomes accumulate. A campaign that has worked through its audience looks stopped — check the progress bar.
Check the phone numbers
Numbers without a country code will not dial. Classic symptom of an imported list, and it can affect the whole audience at once.
Check the calling balance
It is real money and it runs down. A campaign that stops mid-run with everything else configured correctly may have run out.
Check it worked
Open one contact from the audience and read the activity feed. If attempts are there, the campaign is running and you have a throughput question. If there are none, it is not running at all — which is a different list of causes.
The parts people get wrong
- Every attempt lands on the contact's activity feed. If you cannot tell whether a campaign is running, one contact's feed will tell you in ten seconds.
- Inbound and outbound draw on one allowance, so a heavy morning on the phones throttles the dialler without anything reporting a fault.