A flexible communication toolkit for synchronous groupware

Abstract

Synchronous groupware applications need to offer each user a consistent view of the interactions represented by the streams exchanged between dispersed groups of users. Using strong ordering such as CAUSAL or TOTAL order to capture and deliver streams' interactions may be too expensive (in terms of delay) due to the variability of the network conditions. This paper builds upon previous work on expressing streams causality and propose a multimodal communication toolkit in order to integrate different delivery modes (e.g. FIFO, CAUSAL, TOTAL) into a single channel (with respect to each of these protocols). Moreover the proposed multimodal channel can handle the mix of any partial or total order protocols. We build an experimental platform for measuring the cost of combining several protocols on various network conditions and show how our communication service can adjust the degree of synchronization according to network variations.