How many people can you have on an Adhoc confernce?
This number would be based on the largest Conference Bridge you have on your system. If you have a Bridge that supports 128 participants you could set the Maximum AdHoc Conference Participants Service Parameter to 128 in theory.
Max: maximum size of largest conference bridge in system
Specifies the maximum number of parties that can be added to a Unicast Ad-Hoc conference.
Hope this helps!