A note on Activesync with Exchange 2013
Exchange ActiveSync is a client based protocol that allows you to enable sync between Exchange Mailbox & a Mobile device.
This way one can access all corporate email, calendar, contacts, tasks etc using their mobile device. Exchange ActiveSync protocol is based on HTTP and XML. The feature is enabled by default while installing the Exchange 2013.
What are the benefits of using ActiveSync Feature in Exchange?
=> The most useful benefit is to access the corporate email, calendar, contacts, tasks etc on our Mobile phone (Smart Phones, Tabs, etc)
=> We do not require any additional Server unlike the BES server.
=> We can control all the settings through the policies in the Exchange Server for ActiveSync.
=> ActiveSync supports various Mobile solutions like, Android, iPhone,Windows Phone,Symbian etc.
So what are the various components used in ActiveSync?
Direct Push
Active Sync Access States
AutoDiscover
ActiveSync Mailbox Policies
Let’s see a brief explanation about each component below.
Direct Push:
Direct Push is a feature that updates new content instantly when it is ready to be synchronized. It is enabled in Exchange 2013 by default. Direct Push works in such a way that it issues a HTTPS request to the Exchange Server from the mobile device that supports Direct Push. The Exchange Server keeps monitoring the activity on the user’s Mailbox to see if there is any changes like new/updated calendar, new email, contact or a task it sends a response to the mobile device.
How does Direct Push works?
=> Mobile Device (configured to sync with the Exchange 2013) => issues an HTTPS request to the Exchange Server (this request is also called as PING). => This request informs the server to notify the mobile device if any item change that will occur in the next 15 minutes in any of the folder that is configured to sync with the Mobile device => if not the Exchange Server returns an HTTP 200 OK message => this 15 minutes time span is called as a “heartbeat interval”. The Mobile device goes to standby mode until then.
=> If there is no item change in the 15 minutes time span the Exchange Server returns a HTTP 200 OK response => Once the Mobile device receives this 200 OK response it resumes all activity also called as “waking up”. The request is issued again & the process is restarted.
=> If there is any item that changed or a new item change that is received within the heartbeat interval (15 minutes) the Exchange Server sends response to the mobile device that there is new / change in the item along with the name of the folder in which the change occurred => After Mobile device receives the response it sends a synchronization request for the folder that had a new item or a change. => After the synchronization is completed, a new PING request is issued by the Mobile Device. Then the whole process starts over again.
ActiveSync Access States
ActiceSync Access State is the status of a particular device. There are five access states such as: allowed, blocked, quarantined, device discovery & Mailbox upgrade. Let’s see about each state in detail:
Allowed Access State:
A Mobile device in the allowed access state synchronizes email, calendar, task etc as long as the ActiveSync Mailbox Policy is in effect for that specific user Mailbox.
Blocked Access State:
A Mobile device can be in blocked access state for two reasons. One being the device access rule is preventing the device from connecting (in this case user will receive an email message saying that their device is being blocked) & the other one is that the Mobile device is not compliant with the ActiveSyncPolicy or that user mailbox.
Quarantine Access State:
This state is similar to the block access state. Mobile device will be placed in quarantine access state if the default access level is set to quarantine or if there is a device rule is configured to quarantine the specific device type. Also the user will be notified with an email message stating that his device has been quarantined.
Device Discovery Access State:
When the Mobile device connects to the Exchange Server for the first time, it spends about 14 minutes in the discovery state as the Exchange Server finds out what to do
Mailbox Upgrade Access State:
Well this is a temporary state when a user mailbox is moved from legacy Exchange server to the Exchange 2013 Server the device updates itself for the new version of the ActiveSync & will be recognized by the server.
AutoDiscover
The same old AutoDiscover, similar to the process that works with the Outlook & the process is simplified for the configuration of a new mobile device connectivity to a Mailbox. To configure active sync on mobile device, we only require the email address & the password.
ActiveSync Mailbox Policies
There are several ActiveSync Policies we can define & apply according to our business requirement. Few are password policy, set a device encryption, minimum password length, encrypt storage card etc.
Ratish Nair
Microsoft MVP | Exchange Server
Team @MSExchangeGuru
