Future Generation Computer Systems 21 (2005) 823–839 Cooperative control of multicast-based streaming on-demand systems Giancarlo Fortino a, ∗ , Carlo Mastroianni b , Wilma Russo a a DEIS, University of Calabria, Via P. Bucci, 87036 Rende, CS, Italy b ICAR, Italian National Research Council, Via P. Bucci, 87036 Rende, CS, Italy Received 12 February 2004; accepted 23 August 2004 Available online 25 February 2005 Abstract This paper proposes the COoperative COntrol Protocol (COCOP), which enables a synchronous cooperative group to in- teractively control an on-demand server which multicasts time-dependent data streams. Multicast-based streaming on-demand systems such as video on-demand systems, web casters, and networks of real/virtual sensors can beneficially exploit COCOP to provide cooperative control sessions as a mainstream service. In order to improve efficiency and scalability, the protocol relies on a reliable multicast transport layer which can be based either on the IP-multicast or on Application Layer Multicast. Performance evaluation of COCOP was carried out on multicast trees by using a discrete-event simulation framework. © 2005 Elsevier B.V. All rights reserved. Keywords: Multicasting; Cooperative playback systems; Synchronous group coordination; Discrete event simulation 1. Introduction Multicasting is a primary enabling technology which efficiently concurs to save network resources and easily features multi-party communications. In IP- based networks multicast is exploitable either at the network level through the native IP-multicast service [17] or at the application level through Application ∗ Corresponding author. Tel.: +39 0984 494063; fax: +39 0984 494713. E-mail addresses: g.fortino@unical.it (G. Fortino), mastroianni@icar.cnr.it (C. Mastroianni), w.russo@unical.it (W. Russo). Layer Multicast (ALM) protocols [1]. Synchronous, multi-party and multimedia distributed applications, such as media on-demand, video conferencing, web casting, and shared workspaces systems, are effec- tively supported by multicast technologies, without which their development would be difficult to achieve [4,5]. Such applications are based on the following main basic services: (i) multicast real-time data de- livery, which involves the multicast transmission of time-dependent data streaming to or among a group of clients, and (ii) synchronous group coordination, which allows for interaction among the group mem- bers and synchronized access to shared resources. The integration and customisation of these services and 0167-739X/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.future.2004.08.002