baileyj,
The OAI Stream is everything that is going on in the system. You would need to setup your system to send out the information and then read it. If you don't know how to read the stream then you will need to call Mitel or post it on the forums here.
Is it possible all of those phones are in an ACD Hunt Group and they are getting an alert that there is a call waiting to be answered?
Thanks,
TE