Application behavior and performance on asymmetrical links

Abstract

Nowadays most of the access networks have asymmetrical bit rates; these networks (especially mobile networks) have high delays, packet losses and most often non neglectable jitter. In this degree project, we have studied the behavior of several different types of access networks with asymmetrical conditions. We have worked with the Kaunet deterministic network emulator to achieve practical results of these access networks. With the network emulator we have created different types of asymmetrical traffic data. The applications we have studied are Skype (voice/data in real time), web browsing (HTTP), TVUPlayer (P2P-TV), Bit Torrent (P2P sharing data) and data transmission in FTP. We analyzed how the protocols and the applications behaved in a theoretical way and then we tested them in a practical way with Kaunet. We studied how asymmetries affect delay times, packet losses and jitter introduced in the network and for each application we gave boundaries for a good performance for the mentioned parameters. Furthermore we analyzed bottlenecks and tried to minimize them. Finally, we compared the data from the different types of generated traffic and made some conclusions about the behavior of these applications in an asymmetrical environment.