While creating the campaign, you will be asked to indicate 'Number of Tries'.
In case a customer's number is not reachable, busy or unavailable, the call status is paused for that number and another call is placed to that number after a while (defined by you in the 'Minimum minutes between retries' section.
Number of tries indicate the number of times a call will be placed to the customer before marking it as 'processed' with the relevant status. For example, if you set the number of tries at '3', then each number will be dialled a maximum of 3 times. If the call is not answered by the 3rd try, the dialler will no longer call this number and the call will be registered as 'failed'.
You can check the total failed call count and the total number of tries that were done to a specific customer in the detailed reports. The report can be downloaded from the Campaign log screen.
Please note: A higher number of tries will increase the overall order completion time for you.