Updating schedule information retrieving busy information from server
To answer that, let’s look at two scenarios: For #1, you could do this either via a trust or no trust.
Instead we will access the target mailbox’s free/busy data directly from the calendar (via the Availability service).Note: In order to maintain backwards compatibility, Exchange 2007 mailboxes using Outlook 2007 clients will utilize the Availability service for retrieving data, but also publish to a free/busy public store, since legacy clients also need to retrieve free/busy data. Then the CAS server will make an HTTPS connection to the target CAS server. The target CAS server will obtain the F/B information by communicating over MAPI to the mailbox server and then send it back to the source CAS server. The source CAS server will then provide the data back to the Outlook 2007 / Outlook Web Access 2007 client.This table explains what method is used for free/busy in the different topologies: So how does this work? Well the client will make a connection to the CAS server (if Outlook 2007, this will be determined via the Auto Discover configuration) using the Availability URL. In addition, the Availability Web Service enables the user to share their calendar information in more granular ways.For each target person/group, the user can choose one of four levels of sharing: In previous generations of Exchange, allowing free/busy access between Exchange organizations was an arduous process involving a directory synchronization process and the use of an Exchange Support Tool, Inter-organization Replication Tool (IORepl).IORepl is a MAPI-based application that allows for the replication of public folder data between two organizations.