Videoconferencing on a LAN/MAN architecture: service evaluation and system dimensioning

We examine the performance offered by a DQDB MAN subnetwork when the workload is generated by two different videoconference tools in use by a community of workstations dispersed on local area networks and connected to the MAN by DQDB/Ethernet switches. We evaluate the possibility of offering a videoconference service to a large community of users dispersed on a metropolitan area, reserving investments and pre-existent devices. For such a purpose, we developed a dimensioning methodology for traditional packet switched networks and applied this methodology to the design and dimensioning of an interconnected LAN/MAN system providing the videoconference service. The method allows a separate dimensioning of each subnetwork in the LAN/MAN system. Real videoconferencing tools using different compression schemes are used as traffic sources, thus allowing a comparative analysis of the impact of different coded video streams on the network performance