RRG: redundancy reduced gossip protocol for real-time N-to-N dynamic group communication

Abstract

Real-time group communication is an indispensable part of many interactive multimedia applications over the internet. In scenarios that involve large group sizes, sporadic sources, high user churns, and random network failures, gossip-based protocols can potentially provide advantages over structure-based group communication algorithms in ease of deployment, scalability, and resiliency against churns and failures. In this paper, we propose a novel protocol called Redundancy Reduced Gossip for real-time N-toN group communication. We show that our proposed protocol can achieve a considerably lower traffic load than conventional push-based gossip protocols and conventional push-pull gossip protocols for the same probability of successful delivery, with higher performance gains in networks with smaller delays. We derive a mathematical model for estimating the frame nondelivery probability and the traffic load from overhead, and demonstrate the general correctness of the model by simulation. We implement a functioning prototype conferencing system using the proposed protocol, completed with functions including NTP synchronization, dynamic group size estimation, redundancy suppression, and other features needed for proper operation. We perform experiments over the campus network and PlanetLab, and the prototype system demonstrates the ability of our protocol to maintain robust performance in real-world network environments.

Peer-to-peer real-time group communication over content-centric network

“…Redundancy Reduction Gossip (RRG) is a protocol proposed for real-time group communication [16,17]. RRG demonstrates churn and sporadic traffic coping capability and highly efficient real-time N-to-N dynamic group communication in IP networks.…”

“…RRG is a gossip-based protocol intended for achieving highly efficient real-time N-to-N dynamic group communication in IP networks [16,17]. Unlike other gossip protocols, which are mostly push-based protocols [21,22], RRG randomly establishes connectivity during the spreading of each message, called a cycle, and performs a limited number of push-pulls operations within a cycle.…”

“…Fig. 6 shows the nondelivery probabilities from the mathematical model [16], over IP network and over CCN. Because of the negative interest scheme and the caching employed, the non-delivery probability against the fanout over CCN is much lower than that over IP network and the mathematical model.…”

“…A new peer joins the group through the bootstrapping point as described in the paper [16]. Shortly afterwards, its contact information is learned by other peers through the subsequent gossips.…”

“…There are several challenges to overcome in designing a real-time group communication protocol, for example how to meet the stringent delay requirements, and how to handle user churns [15] caused by peer joining, departing and failing. The most difficult challenge is how to reduce the large amount of traffic generated by the N-to-N nature in such applications.Redundancy Reduction Gossip (RRG) is a protocol proposed for real-time group communication [16,17]. RRG demonstrates churn and sporadic traffic coping capability and highly efficient real-time N-to-N dynamic group communication in IP networks.…”