Lotus Notes stores free and busy information in a Lotus Notes database called Busytime.nsf. Busytime.nsf is managed by a standard Lotus Notes server task called Schedule Manager, which is started automatically whenever the Notes server starts.
Note Busytime.nsf cannot be replicated to other servers.
When one Lotus Notes user queries another Lotus Notes user's calendar, Schedule Manager attempts to supply the free busy information. It checks the Notes Public Name and Notes Address Book (NAB) to determine if the user's free and busy data is on the local Lotus Notes server. If so, the user's free and busy information will be stored in the local instance of Busytime.nsf. Schedule Manager simply looks up the information and returns it to the requester.
If the requested information about the user resides on a different server in either the same or different Lotus Notes domain, or if the user is in a different system altogether, then Schedule Manager passes the request to a second server task called Calendar Connector, a Calendar Connector specific to Lotus Notes. The Notes Calendar Connector task re-routes the request to a Calendar Connector task in the other domain. If the request is sent to an Exchange domain, the Calendar Connector task is a new task, called Exchange Calendar Connector (or Excalcon.exe), which is added to the Notes server as part of the Exchange Calendar Connector installation process. When the requested data is returned to the Lotus Notes system, the Lotus Notes Calendar Connector task returns the data to the requesting client.
Tip Lotus Notes users should permit other users to access the free and busy information in their calendar profiles. Exchange users will not receive a warning that Lotus Notes users' free and busy information may be out of date for those users who have restricted this access.