Discuss role of each component: Video Conference Application implements the business logic: PIN number validation, control of the conference mode Video phone, mobile phone, PC: establish call with conference application, transmit and receive audio/video to/from media server Media server: performs audio mixing, muting participants, video switching or mixing Discuss protocols: SIP for signalling RTP for media. There are two separate RTP streams per video phone: one for audio and one for video
Note that sending an SDP with “a=recvonly” to the participant device is not secure: there is no way to know if the participant device will comply.