"Not Enough Configured Switch Ports Available" Message when trying to Extend

Symptoms:
"Not Enough Configured Switch Ports Available" message received when trying to extend an ongoing conference after a second conference has been scheduled.

Problem:
When you schedule 2 independent conferences (NO overlapping time period) with unique site names, the MCU will assign the SAME MCS listed phone number because it knows that the 1st conference will end before the 2nd conference begins. However, it does not take into consideration that there is a possibility that the 1st conference might wish to extend beyond the start time of the 2nd conference.

Resolution:
When scheduling a Conference, allocate a time in the Extend Buffer Field, this will ensure your resources are available incase an extension is needed.

Additional Notes:
Additional workarounds are:
1) Configure the MCU for Single Dial in Number
2) Manually Allocate MCU Numbers.