This paper presents a comparative study of different techniques aiming at t
ransmitting MPEG-2 streams over ATM networks, with emphasis on the presenta
tion of practical results achieved on an experimental platform available at
LSI, a laboratory of the University of Sao Paulo, Brazil. This study has t
he purpose to determine some tuning parameters for optimizing the implement
ation of distributed multimedia applications on different network technolog
ies. The focus of this experimental study has been on non-native ATM techni
ques like "Classical IP over ATM" and "LAN Emulation", as well as native AT
M techniques based on direct access service primitives to AAL5. The influen
ce of different parameters, like packet length, buffer size, CPU speed, on
the resulting throughput has been studied. Furthermore, a testing tool is b
eing developed for assessing the transmission of MPEG-2 streams based on th
e practical experience achieved so far. These results will permit the evalu
ation of different network technologies and also help in the development of
distributed multimedia applications like video-on-demand, videoconferencin
g and telemedicine.