Here at the University of Wisconsin-Madison, we have built an IP video system we call the Digital Academic Television Network <http://datn.wisc.edu/>. For the channels we get from the cable TV company, we use a locally-scoped IP multicast address. The router does not forward these, so they can only be viewed on the campus. However, the channel from the Journalism Department uses a globally-scoped address, so should be viewable elsewhere on the multicast-enabled net. The benefit of IP multicast is that it scales to large numbers of viewers without increasing server or network load. The drawback of IP multicast is that the server doesn't know who is watching. So I am looking for advice: how can we track viewershi of IP multicast video? Dave Devereaux-Weber ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.