So, we have struggled with this issue for years, to the point that details about it have passed from fact into lore, but we have a queue that will occasionally send a second call to an agent who is already on the phone with another queue call, or perhaps an outbound call.
The extension has call waiting disabled. The Cisco 7960 phone being used has its call_waiting setting disabled. The queue is configured like so (plus agent restrictions is set to “Extensions Only”):
 announce-frequency=0 announce-holdtime=no announce-position=no autofill=yes autopause=no autopausebusy=no autopausedelay=0 autopauseunavail=no joinempty=yes leavewhenempty=no maxlen=0 memberdelay=0 min-announce-frequency=15 musicclass=default penaltymemberslimit=0 periodic-announce-frequency=0 queue-callswaiting=silence/1 queue-thereare=silence/1 queue-youarenext=silence/1 reportholdtime=no retry=5 ringinuse=no servicelevel=60 strategy=wrandom timeout=25 timeoutpriority=app timeoutrestart=no weight=0 wrapuptime=30 context= lazymembers=no
What can I start digging for in the logs to figure out why this happens from time to time? When we have an issue, we often see a single call that is repeatedly ringing agents that are not available or on a call, even while other calls that have been waiting for less time are presented to available agents. I do understand that the autofill setting will mean that calls won’t always be answered first-come, first-served, but when we have an issue, it’s particularly bad (one call holding 8+ minutes, another answered after 10 seconds).