General and scalable state feedback for multimedia systems

Obtaining feedback information regarding the state of receivers in a multicast session is a fundamental problem that often arises in collaborative multimedia systems. In this paper we present a generalized abstraction of the state feedback problem. Then, we present a feedback protocol that addresses some of the special cases that commonly arise. The presented feedback protocol is suitable for application in best-effort unreliable networks such as the Internet. It allows for obtaining the desired state feedback about a group of receivers, where each receiver may be in one of a set of finite states. The efficiency of the proposed protocol in eliminating the reply implosion problem is illustrated by simulation experiments.