I did find this - I think it may apply (as I am looking for the same answer) - and it appears that once we are in a DOWN state the polling resumes based on whatever interval you have placed... for me that is 2 minutes. For you mcordero it would be your 300 seconds / 5 minutes. So Max time to UP status is 4:59.
Thanks to Karlo.Zatylny for this
Here is the algorithm:
1. Try to ping the device
2. Did we succeed? Yes go to 4. No, go to 3.
3. Should we try again (we've tried less times than we are configured to)? Yes, go to 1. No, go to 4.
4. Notify the system of the success or failure of the ping.
From here I would guess that it waits for the next interval to ping again.
You are welcome. Thanks for the correct answer.