Hello all, I have found a good program which can converse voice and video into media files. It is provided by Ozeki VoIP SIP SDK and with it you can play back the pre-recorded media file into a SIP call. If you are interested in media file conversion technologies you can read more on this site (use google ->voip-sip-sdk.com/p_407-voip-audio-conversions-voip ) Regards, Erik