The Daemon Role

A collaboration typically defines a special role called daemon, which controls for example who is allowed to take which roles and how many participants can take a certain role . When a participant attempts to take a role from an ongoing session, the daemon of that session is contacted. Possibly authentication is performed. Only when the participant is qualified by the session control policy does she obtains the rule set specified for that role. A session without a daemon role will be open to all, i.e., any participant can take any role.

The session control may not necessarily be centralized. It is possible for a session to have multiple daemons, e.g. for availability and scalability. The user can specify a daemon role which can be taken by multiple agents.