This short paper will document a demonstration given at the Third Ka‐band Conference, Sorrento, Italy, September 1997. The principal objective was to illustrate interoperability over a complex hybrid satellite and terrestrial Asynchronous Transport Mode (ATM) network. The network linked Ka‐band satellites in Europe and in North America, via the European JAMES Research and Development (R+D) Network, and the CANTAT‐3 trans‐Atlantic submarine fibre. The ISABEL application facilitated Computer Supported Collaborative Workspace (CSCW) among locations in Canada, Italy and the U.S.A. The demonstration consisted of the presentation of one full conference session from Italy to observers in Canada and the U.S.A., with the opportunity for the remote, as well as the local audiences, to interact with presenters during the ‘Question and Answer’ periods. There were also short presentations from the Communications Research Centre (Canada), and NASA Lewis Research Centre (U.S.A.).
The ISABEL application required two virtual networks, one to handle unicast signals for control and monitoring, etc., the other to distribute multicast traffic. They shared a common star topology over point to point symmetrical Virtual Paths (VPs) through the interconnected ATM networks. The three participating locations were connected to a Network Node at the Communications Research Centre (CRC), Ottawa, Canada over full duplex E1 (2·048 Mbps) circuits. The application traffic from each ISABEL workstation was directed to the Network Node, where it was combined. The Control Workstation, at the Conference Centre, Sorrento, Italy, allocated window sizes in the combined image, selected local inputs, and switched presentation material as required. The combined image was multicast from the Network Node to the three networked locations.
The overall network included the Italsat‐2 satellite and the U.S. Advanced Communications Technology Satellite (ACTS), the Canadian and Italian national test networks, the European R+D network, and the CANTAT‐3 submarine fibre. Copyright © 1999 John Wiley & Sons, Ltd.
