I have two domains that are on two separate forests. I have setup a two way forest wide trust between them which is functional. I need to setup calendaring whereby exchange server A on domain A can view free/busy schedule and book meeting rooms on Exchange server B on domain B side and vice versa. Thanks

you need to use Federated trust & sharing as in Exchange 2010 . This can be doen on Exchange 2007 with latest Service pack.

I have exchange 2007Sp1 on one side and a exchange 2007 sp1 CCR cluster on the other

I think yoiu need to upgrade to the latest service pack to get the federated trust settings

will this solve the issue or is it a step in the direction.

You need exchange 2007 SP2. http://technet.microsoft.com/en-us/library/dd638083.aspx This should be helpfu http://blogs.technet.com/b/ucedsg/archive/2010/04/22/how-does-federated-calendar-sharing-work-in-exchange-2010.aspx http://www.stevieg.org/2010/08/federation-onpremise-outlooklive/l

Looking at the blogs you send me you need to have at least 1 exchange 2010 CAS box on your network. Which i dont have....

yes . you need exchange 2010 Cas.

Unfortunately we dont have any plans just yet for exchange 2010 cas

Hi ExchangeMK, We can share free/busy information cross forests with Exchagne 2007. for detailed, see "How to Configure the Availability Service for Cross-Forest Topologies at "http://blogs.technet.com/b/exchange/archive/2011/03/04/3412075.aspx. Fiona

Hi, Thanks for the solution managed to resolve on wednesday. Used similar commands