VoIP/SIP Interactive Voice Recorder

This project is about a component we need and once started to develop the class structure. Basically its simple, its a server side VoiceRecorded with the possibility to control recording sessions like start/stop/rewind etc. We will most likely use SIP, but we want to have this open so the recorder itself should take a Provier interface so we can implement any kind of data/voice provider. See the attached solution which is what we done w while ago. It looks like it has everything, so it just needs to be implemented, but feel free to add your comments if something is missing or bad designed. You can use third party libraries IF they can be used in commercial applications !