http://blogs.technet.com/markga/archive/2008/09/05/what-type-of-bandwidth-does-ocs-web-conferencing-use.aspxI had this question from a large school district down in Florida and the answer is it depends on what aspects of the OCS conference you are using. Here is a bandwidth breakout of the conference scenarios:   Application Sharing bandwidth: Peak Bandwidthen-USCommunityServer 2.1 SP1 (Build: 61025.2)