Recommendation ITU-T J.388 defines a system for real-time video/audio transmission over an IP-based network. The protocol of the system consists of session control and media transmission.Session control is based on the session initiation protocol (SIP),and for the use of SIP this Recommendation refers to Recommendation ITU-T J.366.4.Several types of packet formats are defined for media transmission.With regard to codecs,this Recommendation provides some mandatory codecs and some optional ones.The system equipped with the protocol specified here can be used for bidirectional applications, such as video telephony,as well as unidirectional applications,such as video news gathering.Even in case of video news gathering,bidirectional transmission is often required for communication between a reporter in the field and the studio.In addition,the system is defined taking into account implementation complexity.Thus,a software-based embedded solution is also available,which requires less cost and a shorter development period than a hardwarebased one.