From Role Based To Service Based Management

Microsoft has made several changes regarding the architecture stand point to improve the performance:

  • Client Access Server role handles the authentication (CAS does not manage the authentication itself but uses it thanks to server active directory requests) redirection, and proxy services
  • Mailbox Server role includes the server components counting unified messaging and transportation services

The services are still critical for the end users and they are managed in a totally different ways from an Administrator perspective. Which services are we talking about?

Transportation Services

User Connectivity Services

Mailbox Availability Services

End User Service Monitoring

There are other main services in Exchange 2013, such as Unified Messaging or DLP, etc. Right now, GSX is focusing on the major ones.

Since everything is now merged, we decided to monitor and report on each of the services provided by the server role.

 Transportation Service

The Transportation Service is now handled by the CAS and Mailbox role servers.

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Figure 1: Source Technet

The Front-End Transport Service is now running on the Client Access Server. The service acts as a stateless proxy for all inbound and outbound external SMTP traffic for the Exchange 2013 organization. As it is just a proxy, this service does not inspect or queue any messages locally, it just communicates with the Transport service of the Mailbox Server.

What does GSX do?

To monitor the transport service, which is separate on the CAS and the Mailbox, GSX checks every critical component on the server and identifies them as service components.

On the CAS:

  • GSX checks the availability of the CAS itself at a system level
  • GSX verifies the availability of the Front-End Transport service
  • GSX collects SMTP statistics
  • GSX checks the availability of the redirection services

On the Mailbox:

  • GSX checks the availability of the Mailbox Server at a system level
  • GSX verifies the availability of the Transport Service and Mailbox Transport Service (with Mailbox Transport Delivery services and Mailbox Transport Submission services) on the Mailbox Server.
  • GSX checks the queue in the Mailbox server just as in a 2010 Hub server.
  • GSX collects statistics on message queues and deliveries.

 Exchange server creation



 User Connectivity Service

The CAS is no longer responsible for user protocol management. The CAS is now acting as a proxy and provides the Administrator with authentication through the active directory server. It simply redirects the end users request to the closest Mailbox Server or to the Primary Active Manager that will determine which Mailbox Server is hosting the active copy and then proxy the request.


When an end user tries to connect to the Exchange Server through OWA, Outlook Anywhere, Active Sync, EAC or PowerShell, the CAS handles the connection through the IIS (Internet Information Service).

The CAS then communicates with the Mailbox Server through a HTTP call (RPC over HTTP). Does that mean we do not need to pay attention to the former protocol?

The answer is no. When the connection is made to the Mailbox Server, this one still handles the connection with these protocols. They are supported on the Mailbox Server role and not on the CAS role.


There are exceptions: IMAP, POP, SMTP and UM.

These connections are redirected to the Mailbox Server with specific services. As an Administrator, you need to be sure that these IMAP/POP, SMTP and UM services are working well on the CAS and Mailbox servers.


Sum Up

The user connections are redirected by the CAS to the Mailbox Server.

For this service to be healthy you need:

  • To make sure that the IIS, IMAP/POP, SMTP and UM services are working well on the CAS
  • That the CAS is able to authenticate the user via the Active Directory Server
  • That it is able to communicate with the Mailbox in HTTP
  • To have the protocol working on the Mailbox Server (OWA, Active Sync, EWS, ECP, OAB, POP, IMAP, UM)
  • To have the active manager to communicate to the right Mailbox

Checking the availability of these services is challenging, as you have to verify the service on each of the server roles.

What does GSX do?

Testing the user connectivity is still critical for IT Administrators. Therefor we have to test this service on the CAS and on the Mailbox separately to make sure everything is working fine.

On the CAS:

  • GSX monitors the CAS availability from a system perspective
  • GSX monitors the proxy health sets for each protocol

Thanks to the end users “Scenarios” GSX tests the CAS service delivery at the connection and redirection level from an end user perspective.

On the Mailbox:

  • GSX checks the Mailbox availability at the system level testing the user connection protocols: OWA, Active Sync, Outlook, POP, IMAP, Exchange Web Services (EWS), Autodiscover and Unified Messaging (UM) through the status of Health sets on the Mailbox Server:
    • ActiveSync.Protocol
    • Autodiscover.Protocol
    • EWS.Protocol
    • IMAP.Protocol
    • Outlook.Protocol
    • OWA.Protocol
    • POP.Protocol
    • UM.Protocol

Protocols service

 Mailbox Database Service

The Mailbox role has more services to handle on Exchange 2013 compared to previous versions.

All the processes around Replication inside the DAG (mounted, dismounted, healthy and unhealthy copies) are still the same. The only big change is that there is no longer a MAPI protocol (to discuss between the CAS and Mailbox Server).

We still manage the Database, gather information on the mailboxes and manage the DAG (the same way our single copy alert did, with additional replication services).

What does GSX do?

Mailbox Database Availability

There are several ways of testing the availability of the Mailbox database in GSX Monitor:

  • The Mailbox server availability is tested as GSX checks if a remote PowerShell session on the server can be opened
  • Mailbox Database management: If at least one Mailbox Database is not mounted or healthy, an alert will be sent and the status of the server will be down
  • Database statistics will be displayed the same way as they are currently for Exchange 2010 databases (sizes, number of Mailboxes, etc.)
Mailbox Database Management

GSX Monitor & Analyzer provides the same features for the Database Management: 

  • Database up or down statistics are available in GSX Analyzer
  • Statistics on Database usage: size, number and size of Mailboxes at the DB level and DAG level
  • The statistics view contains the same statistics for Exchange 2013 as it was for Exchange 2010- read more
  • Ability to exclude non-replicated Databases from the DAG checks (for recovery, etc.)
  • Alerts are available on the Database size in the Mailbox wizard section
  • Impacts on the status of Mailbox server (shows whether Mailbox Databases are mounted or dismounted)
  • Impacts on the DAG availability (in case there is a single Database copy inside the DAG)
  • Alerts on a Database failover which includes database statistics on failure

 End User Monitoring

The three services we mentioned above are very critical services for any user, as they determine the accessibility to Exchange infrastructure and its Mailbox, to send and receive emails.

The user performance from a user perspective is also important to measure, in order to prevent any complaints from the Business line and Help Desk. Availability is very important to manage, but the end user performance is the most important. This performance is the key point to end user satisfaction when using IT resources.

The IT Manager needs to prevent any lack of performance to occur, in order to limit complaints about the IT infrastructure.

To keep an eye on this fundamental user experience, GSX Monitor & Analyzer allows you to simulate the user in running multiple scenarios, which represent his day-to-day life including:

  • Opening a Mailbox
  • Creating meetings, tasks and folders
  • Downloading attachments from an email
  • Searching for folders, email, appointments and tasks
  • Creating and sending emails

 Scenario settings

These scenarios can be performed simultaneously on different versions of Exchange. This means you can run them on Exchange 2010, Exchange 2013, Exchange Online or on a Hybrid environment from one environment to the other!

Simulating classic day-to-day tasks like checking the execution time of the Exchange services represents multiple tasks such as opening a mailbox, opening a document stored in a folder, etc. Checking the execution time of the entire sequence and of each action in the sequence is crucial to manage the performance of critical activities for Business Line.

With GSX, IT Administrators monitor each activity for organizations running on either Exchange on-premises or Online.

Scenarios Status 

Mail routing is also critical to verify the end user service monitoring and not only for an organization running Exchange in a Hybrid Cloud environment. GSX Monitor can monitor mail routing between multiple servers and allows tracking mail routing performance between both environments to make sure that the routing path is in line with the pre-set SLAs.

These scenarios report on service uptime and latency. They also have a threshold to alert when there is any slowdown in performance. The amount of success, failure and average execution time is displayed here below.

All statistics are integrated into GSX Analyzer to conduct trending.

You can keep track of your main infrastructure services and end user scenarios at the same time in the Exchange 2013 Overview.

Exchange Overview 


From a service perspective, here below are the most critical aspects IT Administrators need to be confident about regarding their level of performance:

  • Access to the Mailbox in multiple ways
  • Mailbox availability and storage
  • Email transportation

Moreover, a user performs multiple daily actions on the Exchange environment and the Business line the satisfaction is critical when you have to manage an IT infrastructure. Therefor, you need to provide availability on the platform as well as performance over time.

  • How long does it take for end users to access their Mailbox, send an email, synchronize active sync devices, create meetings, download attachments, etc.?

These metrics must be tracked carefully by the IT department to detect any slowdowns in performance that can lead to business complaints, or worse, unavailability of the platform.

This is what GSX is doing not only from a system perspective but also from an end user point of view in on-premises, Hybrid or full Cloud environments.