Bandwidth Estimation and Rate Control in BitVampire CPSC 527: Advanced Computer Networks

We consider the problem of bandwidth estimation and rate control in the context of the peer-to-peer video streaming application BitVampire. BitVampire requires each peer to maintain an estimate of its available upstream bandwidth. This is needed by a scheduling algorithm which takes in- formation about peer's bandwidth into account in order to minimize the initial buering time when watching a video. It is also an interesting problem in general, since P2P ap- plications can generally oer a better quality of service if they are aware of their bandwidth limitations. We looked into the area of bandwidth estimation and evaluated their applicability for the context of P2P applications. We found that it is not easy to use them in this context since most of them require very accurate timing and low level network access which is often not given by high-level programming languages like Java. We went for a pragmatic approach in- stead, which uses round-trip-time measurements as an in- dicator for the available bandwidth of a peer. We did a prototype implementation in Java and evaluated it in the LAN environment. Future work has to investigate about the choice of many policy decisions which arose when creat- ing the prototype.