The OCS environment allows instant messaging, file exchanges, voice or video calls and web-based conferences, amongst other additional features, see, e.g., [1]. We note that unlike solely web-based conferencing solutions, the OCS environment provides (i) dedicated client software to be installed on participating computers and (ii) access to the system using a browser interface, allowing for broad accessibility. To enable web-based access, the server typically communicates with additional infrastructure servers, such as proxies and gateways. Here we provide a first evaluation of the bandwidth utilization characteristics for the Microsoft Office Communications Server (version 2007 R2), which was deployed at an academic institution in the upper Midwest.