Email worked best for communications with students, either singularly or as a group. Everyone is experienced with email applications. Almost everyone uses email at work to communicate with project team members, especially with those located in different parts of the country. Email messages can contain threads, so that anyone can read through the email to view previous discussions. All the course material is available and can be read at the student's pace, within the constraints of the academic term.
Most students can and want to interact using the Internet.
In either case, an important aspect of systems engineering is team dynamics, which is best learned by doing and teaching others. As a consequence, most courses have a mixture of synchronous and asynchronous activities. A generalized model for this mixture has not been formulated. At present, the success of the courses depends on faculty, who orchestrate student activities. Posting of homework and instructor responses and student critiques.