The transmission of DV data which needs 28 Mbps traffic has been possible, because public ATM networks, like Japan Giga-bit Network (JGN) can be used. The DV system not only provides good audio and video quality, but also has a small processing delay. The DV system is suitable for interactive systems like teleconferencing for the small delay. We report the result of measurements of the delay time of DV systems on JGN. DVTS over IP and Sony SEU-TL100 over ATM are measured. The delay time of the systems are 90-220 msec including the NTSC/DV converter. The delay time of the ATM network is 11 msec for Tokyo-Osaka where the distance and routes were varied. The jitters was also varied for congestion analysis. The jitter make the quality of DV decrease rapidly when system buffers are small.