Updating schedule information retrieving busy information from server
The Exchange Server 2007 Availability service improves free/busy data access for information workers by providing secure, consistent, and up-to-date free/busy data to clients that are using Availability Web Service (like Microsoft Office Outlook 2007 or Exchange 2007 Outlook Web Access).
Outlook 2007 uses the Autodiscover service to obtain the URL of the Availability service.
if target mailbox restricted F/B access for source mailbox, then restricted data is returned).
If there isn’t a trust, you define an account that can retrieve the data; the data returned is the default F/B data and doesn’t provide any granularity in terms of permission access).
However, with organization wide free/busy, the availability service can make cross-forest requests only on behalf of a particular organization.
If you couple that with the new Calendar Assistant functionality in Exchange 2007 (namely the ability for Exchange to place meeting requests in a tentative state for mailboxes without the need for the end user to triage the meeting request, and the ability to update meeting requests when certain information changes (location, attendees, meeting notes)), the Availability service provides a methodology by which end users will be able to see free/busy data in real-time that is always up to date.
The Availability Service is a web service that is deployed on the Client Access Server role.
Outlook 2007 clients discover the Availability service via Autodiscover.
The Availability Service is used by the Outlook 2007 and Outlook Web Access Scheduling Assistant to As mentioned above, in order for the Availability Service to provide a seamless end user experience, it must be able to interact with legacy systems.With organization wide free/busy, a user’s default free/busy information is returned and it is not possible to control the granularity of free/busy information returned to users in the other forest.