a little explanation i copied from an older post also regarding something similar to this , i hope it explains the polling a bit.
Now regarding the unanswered polls in the Queue Performance Overview report, this is the times that the Queue polled/rang the specific extension but did not answer the call. Note that the sum of this is not the sum of all unanswered calls of the Queue. For example, lets say that you have a Queue with 4 agents and Ring All strategy and a call comes in the Queue, rings all 4 agents and answered by 1 agent.. In the Queue Performance Overview, you will see:
1 call received
1 call serviced
0 unanswered calls
0 unanswered polls by the agent who answered the call
1 unanswered poll for every other agent