Exchange Server 2010 : Federation Scenarios (part 1) - Free/Busy Access

The common component in all of these scenarios is the creation of a federation trust, for the purposes of this discussion, we will assume that the trust is in place and configured for all accepted domains in the organization.

1. Free/Busy Access

Although federated delegation provides a lot of new functionality with many advantages, the "killer app" is probably providing seamless, basic free/busy information—much like your users are accustomed to seeing when scheduling meetings with other internal users. This is configured at the organization level on a per-external organization basis, with one organization relationship in place with each external organization you want to share free/busy information with. This provides the other organization access to your Availability service at the level of detail specified. You can also restrict which internal users' free/busy data is accessible by specifying a security distribution group; only members of that group will have their free/busy data accessible via the organization relationship. Organization relationships are discussed in detail in the "Organization Relationship" section of this chapter.

The organization-level prerequisites to enabling two-way free/busy access between organizations are:

• Both organizations must be running Exchange Server 2010 Client Access servers.

• Both organizations must have federation trusts created and configured for the SMTP domains of the users who will be accessing free/busy between the organizations. The creation and management of federation trusts is discussed in detail in the "Federated Trust" section of this chapter.

• Both parties must have created and configured an organization relationship with the other organization as discussed in the "Organization Relationship" section of this chapter.

Note:

Although Exchange Server 2010 Client Access servers are a prerequisite, users' mailboxes do not have to be on Exchange Server 2010 Mailbox servers. Mailboxes on Exchange Server 2007 SP2 can use federated delegation by configuring Exchange Server 2007 SP2 Client Access servers to proxy availability requests to Exchange Server 2010 Client Access with the Add-AvailabilityAddressSpace cmdlet. For example, to proxy the contoso.com address space, the cmdlet would be:

Add-AvailabilityAddressSpace -ForestName contoso.com _-AccessMethod
InternalProxy

When the prerequisites and client requirements are in place, your users can access free/busy information for users in the other organization by entering the user's SMTP address in the Scheduling Assistant within a new or existing Outlook Web App or Outlook 2010 meeting request, as shown in Figure 1. Outlook versions prior to Outlook 2007 cannot be used because the free/busy lookup across organizations uses the availability service, and no free/busy information is posted to public folders.