This paper examines the influences of network latency and packet loss on the playback quality of MPEG video on
iSCSI disks. The paper also explains the relationships between the video-playback quality and the transmission
speed, average bit rate of video, file-reading block size, and receive window (RWIN) size. Experimental results
indicate that the additional delay at which the average MU rate suddenly falls down increases as the RWIN size
becomes larger up to the amount of read-response data plus the number of bytes of the iSCSI response header.
In addition, we can reduce the deterioration in the video-playback quality by enlarging the file-reading block size.
This paper proposes an adaptive switching control scheme which dynamically switches between high-bit rate and
low-bit rate video files according to the network load for the playback of MPEG video stored on iSCSI disks.
The scheme adaptively switches read requests between the two video files by estimating the throughput from the
size of transmitted video data and the transmission time. By subjective assessment and objective assessment, we demonstrate the effectiveness of the scheme.