As its importance grows, a company’s messaging application must be always accessible, secure and available everywhere. In recognition of this need, Microsoft Exchange 2010’s architecture was drastically improved compared to previous versions, to offer better scalability and flexibility. Exceliance load balancers leverage this new architecture to ensure availability and optimize performance of the messaging application, however it is accessed through an Outlook client, a web browser or a smartphone.

Exchange 2010: dedicated servers for an upgradable and scalable architecture

Microsoft Exchange 2010’s infrastructure is now divided into five separate but related server roles:

• Client Access Server (CAS): manage client access to email, calendars and contacts
• MailBox Server: host emails and public records
• Edge Transport Server: secure flows (antivirus and antispam)
• Hub Transport: email routing server
• Unified Messaging: centralize all message types (fax, voice) in Outlook 2010 clients

Exchange 2010 messaging application quality and continuity of service

As Microsoft itself advises, a hardware load balancer such as Exceliance’s ALOHA is an effective addition to Exchange 2010 architecture. They intelligently balance the load between multiple client access servers, based on their status, load and/or user access mode.

They make it possible to:

• Perform server health checks: more effective than a ping, the load balancer checks the service status and, if a server is down, automatically reroutes traffic to another server seamlessly for the user.
• Balance the load for all flows and protocols: management of MAPI, IMAP and POP3 flows and TCP, HTTP and HTTPS protocols.
• Ensure session persistence: the methods used to manage user session persistence can be configured depending on the Exchange architecture and messaging client used (Outlook or remote access via Outlook Web App, Outlook Anywhere and Exchange ActiveSync).
• Provide SSL acceleration: the load balancer manages SSL connections directly, which enables the CAS servers to focus on providing the service.