Roadmap

Controlling a multi-party session is a complex task, and there are various axes on which one can design a system to achieve this task:

Distributed versus Centralised

The various control functions (membership, speaker, etc) could be located at a given node, or they can be deveolved to all participants.

Tight versus Loose

The control functions may enforce exact behaviour (e.g. sequence of speakers, or other constraint on concurrent actions), or may leave such decisions (partly or wholly) to human participants.

Homogeneous versus Heterogeneous

A system may allow users to participate when they have limited or different functionality to each other, or may require a common minimum set of functionality for media and control, of all participants, including data delivery mechanisms (e.g. unicast versus multipoint, or multicast; reservations; floor control, and so on).

The rest of this chapter looks at the two main standards arena proposals in the area of conference control from these perspectives.