Note This connection is not referring to the Connection Timeout field that is in the IIS MMC snap-in. Alternatively, modify the minimum heartbeat interval. We recommend that the firewall time-out value be set to a minimum of 15 minutes for the Exchange Direct Push Technology Always-up-to-date (AUTD) feature to perform optimally.
The heartbeat interval is how much time that a mobile device calculates should pass between pings to the server from the mobile device. The session between the server and the mobile device ends if one of the following conditions is true:
- No e-mail messages arrive in the mailbox to initiate a notification.
- There is no response from the server before the heartbeat interval elapses.
Exchange Server 2003 maintains a sliding window of the most recent heartbeat intervals that are supplied to the server by mobile clients. The default value for this sliding window is 200 heartbeat intervals. You can configure this value in the HbiSampleSize registry key. However, it is not expected that the default value will ever need to be adjusted. See the table in this section for the values of the HbiSampleSize registry key.
An event is logged in the Application event log when boththe following conditions are true:
- The average of the heartbeat intervals in this sliding window is less than or equal to the alert threshold.
- There are HbiSampleSize samples.
We recommend that you increase the firewall time-out values for HTTP(S) requests to the Exchange Server Microsoft-Server-ActiveSync virtual directory to provide a richer, "always-up-to-date" experience. The method that you use to increase the firewall time-out values depends on which firewall product you use. Refer to the firewall documentation for information on about how to increase the firewall time-out values.
To configure Microsoft Internet Security and Acceleration Server (ISA) 2004 idle session time-out values for Exchange Direct Push Technology
- In the console tree of ISA Server Management, click Firewall Policy.
- On the Toolbox tab, click Network Objects.
- Expand the Web Listeners node, and then view the properties of the applicable Web Listener.
- Click the Preferences tab, and then click Advanced.
- Modify the Connection Timeout from the default 120 seconds (2 minutes) to 1800 seconds (30 minutes).
- Click OK two times to accept these changes.
- Click Apply.
|MinHeartbeatInterval||DWORD||1 - MaxHearbeatInterval||60 seconds||Minimum heartbeat interval|
|MaxHeartbeatInterval||DWORD||MinHeartbeatInterval -3540||2700 seconds (45 minutes)||Maximum heartbeat interval|
|HbiSampleSize||DWORD||1 or higher||200 samples||Heartbeat interval sample size|
|HbiAlertThreshold||DWORD||1 or higher||480 seconds||Heartbeat interval alert threshold|
- In this table, the value "1 - MaxHearbeatInterval" indicates any value between 1 and the value of MaxHearbeatInterval. Also, the value "MinHeartbeatInterval -3540" indicates any value between the value of MinHeartbeatInterval and 3540.
- If any one of these values is set in the registry, and the specified value falls outside the listed values for that parameter, initialization of Exchange ActiveSync will revert to the defaults. Additionally, an event is logged in the Application event log. However, an event is not logged in the Application event log if the value is set to zero. When a value is set to zero, the behavior is as if the value were absent. In other words, the hard-coded default is used.
- Exchange ActiveSync reads these values one time at startup. Therefore, if an administrator decides to change the values, the IIS Admin Service must be restarted for the changes to take effect.
Release version of Exchange 2007
- In Notepad, open the Sync web.config file on the Client Access Server. By default, that location is under \Program Files\Microsoft\Exchange Server\ClientAccess\Sync.
- Search for and modify the following values as needed:<add key="MinHeartbeatInterval" value="60"></add> <add key="MaxHeartbeatInterval" value="3540"></add>