Free/Busy Tutorial:
http://blogs.msdn.com/deva/archive/2008/10/13/tutorial-free-busy-data.aspx
The availability serive replaced the free/busy PF from Exchange 2003. To see how many availability services exist:
get-autodiscovervirtualdirectory
Basically, Exchange publishes the availability service through a Service Connection Point in Active Directory. The location of the Service Connection Point is in the serviceBindingInformation attribute on the following object:
CN=DC1,CN=Autodiscover,CN=Protocols,CN=DC1,CN=Servers,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=Litware Inc,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=litwareinc,DC=com
Test the Exchange Availability Service:
Test-OutlookWebServices -id:user1@contoso.com -TargetAddress: user2@contoso.com
If the service is not functioning, it's easy to rebuild:
Remove-autodiscovervirtualdirectory
New-Autodiscovervirtualdirectory
