MMLib A Library for End-to-End Simulation of Multimedia over a WAN Jason Gerek ‘98 William Buchanan ‘98 Prof. Mark Claypool, CS Prof. Robert Kinicki, CS

Introduction Multimedia –Combination of traditional mediums –Enhances learning and visualization Wide Area Network (WAN) –Connectivity over “wide area” –Effective and efficient remote communication

Introduction Multimedia over WAN –Quality of Service –Streaming of dataJitter

Purpose Characterize and model behavior –Collect traces –Analyze data, create model, form library Simplify research –Eliminate need for low-level functions –Provide standard toolkit

Hypotheses Network hops affect jitter Delay as a function of distance Lost packets versus network hops

Experiments Design –Client/server structure –Audio and video over UDP Goals –Emphasize behavior of network –Minimize influence of client/server

Analysis Examined relationships Correlation determines behavior of model

Library - Theory Simulates multimedia streams over WAN Behavior based on experimental data Simulation characteristics include: –Delay –Jitter –Packet loss Characteristics depend on media stream

Library - Implementation Initialization: void MMInit(int sim_descriptor, struct connection_info) Generate delay/jitter/loss info: int MMGetDJL(int sim_descriptor)

Demonstration Edited version of ‘mpeg_play’ Two video playbacks: –smooth –jittery Jittery video shows effectiveness of MMLib

Conclusion MMLib –encapsulates properties of multimedia over WAN in simple toolkit –provides easy access to WAN characteristics by specifying several parameters –is a powerful tool which relieves tool creation burden from multimedia researchers

Future Work Broader client code distribution –Internet distribution –More experimental data Additional multimedia stream types Additional network protocols