Hi I have 2 domains on 2 totally separated physical sites. They do not see each other through site to site VPN or other means. No need to mention; but no trust. I have run the commands needed to setup autodiscover on both sides. Also both sides have autodiscover.domain.xxx published on the Internet and it is working fine when testing with outlook autodiscover test. However free/busy is not flowing. I was wondering if there is a need for these sites to see each other and be able to resolve each other's resources INTERNALLY such as DC on the other side. would you please advise? Thanks

What version of Exchange is this?lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com

So sorry Exchange 2007 on one side and exchange 2010 on the other

Hi, If you are asking the GAL, yes, both sites should be able to see each other in GAL (Global Address List). GC server is not recommended to published in Internet. Besides the Autodiscover.domain.com (here domain should be the same as user’s SMTP address), you should also publish your internal EWS URL. For more information, see Configure the Availability Service for Cross-Forest Topologies http://technet.microsoft.com/en-us/library/bb125182.aspx How to Configure the Availability Service for Cross-Forest Topologies http://blogs.technet.com/b/exchange/archive/2011/03/04/3412075.aspx hope it is useful. Best regards, Fiona Liao Email: v-fiolia@microsoft.com IBS TechNet Forum Exchange Support Team Email: v-yuliao@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi Thanks but please wait. What I mean is this. --> Is it necessary for these 2 domains to see each other's resources (such as access to LDAP of the DC on the other domain or setup DNS forwarders)? Remember; there is no trust.

First you need to have the physical connectivity WAN/LAN for both site connected . Then you have to bulid a two way trust between the two sites and after that it is pssible to see the resources on both sides .

End users does not need connection to the other network. Queries for F/B will be handled by one CAS quering a CAS in the other network.lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com

Hi Thanks but please wait. What I mean is this. --> Is it necessary for these 2 domains to see each other's resources (such as access to LDAP of the DC on the other domain or setup DNS forwarders)? Remember; there is no trust. RESOURCE means alot. If you have read the links provided, you will know the answer. there is no need to share DC server for the other domain. Regarding the DNS, again, you must make sure the Autodiscover URL and the internal EWS URL is accessible for end users, so you might or might not need to add DNS forwarders--depending on your external DNS resource. -FionaEmail: v-yuliao@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.