2. There is a configuration settings required to Map the "DLL" to ".so" object in CentOS. Now, the question is which DLL and .so file to be made available and where? " If you are experiencing NullReferenceExceptions with any plugin run through the dialplan, make sure you have included the appropriate entry in your dllmap<http://mono-project.com/Config_DllMap> configuration: <dllmap dll="mod_managed.dll" target="mod_managed.so" os="!windows"/> " mod_managed.so will be in your freeswitch mod directory. All I need is to initiate a call from .NET application and then it should talk to mod_managed module and establish a call. Secondly, I need to know the status of the call such as Ringing, Active, Hangup etc. To initiate a call, try ManagedSession.Originate. -Michael