Experimental comparison of a tree-based and a mesh-based peer-to-peer video streaming system

摘要

We analyse two commercial peer-to-peer (P2P) video streaming systems via active measurements: a tree-based overlay multicast and a mesh-based overlay. Our controlled IP test bed allows us to reproduce near-identical network conditions for both systems and test them under varying network conditions and peer behaviour. We report on how these systems adapt to heterogeneous networks and peer behaviour. Our results include quality-of-service information in terms of the fraction of the total video stream received by each peer for live playback. We also report the server bandwidth versus P2P bandwidth consumed by the system under different conditions. The dynamic behaviour of the P2P video streaming systems is captured via measuring the size of interactions (bytes downloaded) among peers. Finally, we report the correlation between the underlying traffic-shaped bandwidth assigned to a peer and the actual amount of P2P data uploaded by the peer. Our analysis shows that the mesh-based overlay mimics the underlying IP network more closely than the tree-based overlay, indicating that the former relays data volumes more proportionally to the upload capacities. On the other hand, the tree-based system is more efficient in bandwidth usage.