Article ID: 2752387 - View products that this article applies to.
When you configure a federation trust between a local Microsoft Exchange Server 2010 organization and a remote Exchange Server 2010 organization, users from the remote organization cannot see the free/busy information of the users in the local organization.
Additionally, the following errors are logged in the event log on the local Exchange server:
Event Source: MSExchange Availability
Also, HTTP 500 responses returned for Availability requests on the Remote Forest Exchange Client Access server are logged as follows in the W3SVC logs:
POST /autodiscover/autodiscover.svc/WSSecurity - 443 - 10.0.0.20 ASAutoDiscover/CrossForest/EmailDomain/ 500 0 0 15
This issue occurs because the WSSecurity property of the "EWS" virtual directory and the "Autodiscover" virtual directory is disabled on the Client Access servers in the local Exchange Server 2010 organization.
To resolve this issue, run the following cmdlets to enable the WSSSecurty property for each Client Access server in your organization:
Set-WebServicesVirtualDirectory –identity "CASServerName\EWS (Default Web Site)" –WSSecurityAuthentication $true
Set-AutodiscoverVirtualDirectory –identity " CASServerName\Autodiscover (Default Web Site)" –WSSecurityAuthentication $true
Article ID: 2752387 - Last Review: March 25, 2013 - Revision: 4.0