In recent years, video conferencing tools for communication over the Internet have become increasingly popular. From being a technology only available to a limited number of users because of expensive cameras, sound and video capture cards, to becoming an inexpensive and easy to use technology available to a broad public. However, video conferencing tools, like other applications using audio and video to transfer information, require a certain throughput rate (i.e. number of bits per second) to function at an acceptable level. For example, if video is to be used as an asset in a videoconference and not only to indicate presence of the participants, then a throughput rate of 200 to 300 kbps per participant may be required. In addition to video and audio, other video conferencing media such as whiteboard, web and chat also require some level of throughput to function acceptably. This fact affects not only the video conferencing tool but also the other applications hosted on the same network. If the video conferencing tool consumes too much of the networks available bandwidth the other applications will suffer. Mission critical applications may not function as intended, which may have severe consequences. This Master’s Thesis aim is to prevent networks using the Marratech Work Environment tool from being congested by traffic derived from this application. This is achieved through differentiation of certain multicast traffic.