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 Session Initiation Protocol (SIP), and for the use of SIP this Recommendation refers to 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 bi-directional applications such as video telephony as well as uni-directional applications such as video news gathering. Even in case of video news gathering, bi-directional transmission is often required for communication between a reporter in the field and 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 hardware-based one.

Due to a technical error, J.388 was announced for Last Call in AAP 47 (1st November 2006). This consented Recommendation contains a reference to J.366.4 (J.ims.4) which is not yet approved. J.388 should go to Last Call after the approval of J.366.4. Correction to AAP 47 was announced in AAP 48 (16 November 2006).