If you do not want to buy new dsp , check if you have unnecessery media resources configured. Such as confrence bridge or xcoders. You can try removing 1 conf session and it will allow you some channels to configure.
Possibilities1) Corrupt script.2) Codec mismatch.Most of all run reactive debugging and make sure all parameter are getting expected values. If you see inconsistency it is possible that parameter are either incorrect or not defined with correct varia...