Internet
You will need an internet connection that is sufficient (in terms of performance and reliability) to do the activities of the class.
The University has a guideline for the minimum internet connection for students to participate in class (see UW Technology Requirements for Students). Roughly, 15MBps downstream and 5MBps upstream is probably sufficient for the synchronous video we will use for class. In practice, you may be able to get by with less, but it will be hard - since you won’t be able to see things.
My experience is that quality and reliability of connection is more important than locality. I have been able to hold video conferences with colleagues around the globe, but there are some people here in Madison that I need to use the telephone with.
We understand that even the best internet connection is not perfectly reliable. My home internet connection failed while I was proctoring the 559 Final Exam! (it only failed twice in 5 months, both during crucial class events). See the Technology Failures page.