A reliable multicast framework for light-weight sessions and application level framing

TLDR

Reliable multicast delivery performance depends on the underlying topology and operational environment, similar to unicast communications. The paper introduces SRM, a scalable reliable multicast framework, and investigates topology dependence through analysis and simulation, presenting an adaptive algorithm that adjusts control parameters based on prior loss recovery events. SRM is built on IP multicast group delivery, a receiver‑based reliability model, and an application‑level framing protocol, and incorporates an adaptive algorithm that tunes control parameters using previous loss recovery outcomes. The framework’s algorithms are efficient, robust, and scale to very large networks and sessions; a prototype in a distributed whiteboard application was tested globally with up to 1,000 participants, and the adaptive algorithm delivers good performance across diverse topologies.

Abstract

This paper describes SRM (Scalable Reliable Multicast), a reliable multicast framework for application level framing and light-weight sessions. The algorithms of this framework are efficient, robust, and scale well to both very large networks and very large sessions. The framework has been prototyped in wb, a distributed whiteboard application, and has been extensively tested on a global scale with sessions ranging from a few to more than 1000 participants. The paper describes the principles that have guided our design, including the IP multicast group delivery model, an end-to-end, receiver-based model of reliability, and the application level framing protocol model. As with unicast communications, the performance of a reliable multicast delivery algorithm depends on the underlying topology and operational environment. We investigate that dependence via analysis and simulation, and demonstrate an adaptive algorithm that uses the results of previous loss recovery events to adapt the control parameters used for future loss recovery. With the adaptive algorithm, our reliable multicast delivery algorithm provides good performance over a wide range of underlying topologies.