![exchange client connectivity change exchange client connectivity change](https://o365info.com/wp-content/gallery/exchange-2013-coexistence-16/External-Exchange-2007-client-access-optional-scenarios.jpg)
CAS2010 in Site1 will de-encapsulate the RPC data embedded within the HTTP packet and since the target mailbox database is located within the local site, will retrieve the necessary data from the local Exchange 2010 Mailbox server.
![exchange client connectivity change exchange client connectivity change](https://o365info.com/wp-content/gallery/exchange-2013-coexistence-16/Internal-Exchange-2007-client-access-optional-scenarios.jpg)
![exchange client connectivity change exchange client connectivity change](https://techcommunity.microsoft.com/legacyfs/online/media/TNBlogsFS/prod.evol.blogs.technet.com/CommunityServer.Blogs.Components.WeblogFiles/00/00/00/31/06/metablogapi/NoE16Site1_5EB2A83A.png)
There are two namespaces associated with this location – and resolve to the CAS2010 infrastructure.
![exchange client connectivity change exchange client connectivity change](https://4sysops.com/wp-content/uploads/2012/10/Exchange-2013-Data-Availability-Groups-DAG.png)
To that end, this article will begin with a walk through of a deployment that consists of Exchange 2010 in a multi-site architecture and show how the connectivity changes with the introduction of Exchange 2016. Our goal with this article is to articulate the various client connectivity scenarios you may encounter in your Exchange 2016 designs.