Exchange 2013 CAS Configuration In-detail

Exchange 2013 has brought major architecture changes and now there are just two roles – Client Access Server (CAS) role and Mailbox Server role, whereas the previous version of Exchange had five server roles.

Mailbox Server role: It includes traditional features like Mailbox Database, transaction logs, but now it also hosts Client Access protocol, Transport service and Unified messaging server.

Client Access Server role: It is an office client access protocol like HTTP, POP and IMAP and SMTP. Outlook no longer uses RPC to connect to the Client Access Server, it uses RPC over HTTPS (also known as Outlook Anywhere) and Outlook client doesn’t connect using fully qualified domain name (FQDN) or CAS Array as it was done in all previous versions of Exchange. It uses user’s mailbox GUID + @ + the domain portion of the user’s primary SMTP address to connect to the mailbox. This is a huge benefit to overcome limitations and complexity of Exchange 2010 RPC Client Access service on the Client Access Server.

To read about more on this topic, please use the below link at blog.netwrix.com

Exchange 2013 CAS Configuration – PART 1

Exchange 2013 CAS Configuration – PART 2

Exchange 2013 Multi site CAS URL configuration with global name space for site resilience

Exchange 2013 has simplified the Client Access Server (CAS) design architecture using global/single namespace. This is because of the way CAS works in Exchange 2013. Outlook no longer uses RPC protocol to access the email, but instead it connects to the CAS server and accesses the mailbox through https protocol.  The CAS server makes a direct connection with the mailbox server, if the mailbox exists on the same AD site. If not, then it decides, whether to proxy the request or to redirect the request to another CAS/Mailbox infrastructure. It queries the Active Manager to determine the mailbox server hosting the active copy and it will proxy the request to mailbox server. This occurs irrespectively of a mailbox location. One CAS server redirects its request to another CAS server only if there is a telephony related request or an OWA request.

To read about more on this topic, please use the below link at blog.netwrix.com

Exchange 2013 Multi site CAS URL configuration with global name space for site resilience