I keep changing the Service Parameters > CallManager (X.X.X.X) > Clusterwide Parameters (Service) > Maximum Ad Hoc Conference > 8 (suggested value 4)
From a 7900 IP Phone I conference in the 5th person and get "Exceeded Maximum Parties". I can telnet to ACT and issue a show dspfarm profile and view the 4 people in the ACT doing conferencing.
However after a while I go back into CCMAdmin and find the value reset to 4 (default). We have a CMM module with ACT configured in a MRG/MRGL and the customer wants 8 parties in Ad Hoc.