Support for multiway communications in ATM networks

Several multimedia applications like video-conferencing and distributed interactive simulations require efficient support for multipoint-to-multipoint connections from the underlying networks. The routing and signaling protocols for supporting these connections in ATM networks have been proposed earlier by Venkateswaran et al. (see IEEE ATM´97 Workshop, p.263-71, 1997). In this paper, we address the sender identification problem which occurs when multiple senders send data to a multipoint-to-multipoint connection that is identified by a single connection identifier. The various solutions to this problem are systematically categorized into two categories. Using simulation studies of the representative techniques for the two categories, namely VP-merge and VC-merge, we motivate the acceptance for the VP-merge mechanism by showing that the VC-merge technique may require up to 53% more buffer than VP-merge for some typical scenarios. We propose solutions to improve the scalability of the VP-merge technique and describe details of its implementation. Specifically, we identify the VCI collision problem associated with the VP-merge mechanism and propose and analyze different solutions to prevent or resolve VCI collision. The VCI collision resolution mechanism also introduces VP-VC switching, a new mode of operation for the ATM switch, that is different from the standard VP-switching and VC-switching modes of operation