The Device Management (DM) Session
4/8/2010
A Device Management (DM) session consists of a series of commands exchanged between a DM server and a client device. The server sends commands indicating operations that must be performed on the client device's management tree. The client responds by sending commands, containing the results and any requested status information. An example of a short DM session would be the following:
A server sends a Get command to a client device to retrieve the contents of one of the nodes of the management tree. The device performs the operation and responds with a Result command which contains the requested contents.
A DM session can be divided into two phases:
- Set-up phase: In response to a trigger event, a client device sends an initiating message to a DM server. The device and server exchange needed authentication and device information. This phase is represented by steps 1, 2, and 3 in the table below.
- Management phase: The DM server is in control. It sends management commands to the device and the device responds. Phase two ends when the DM server stops sending commands and terminates the session. This phase is represented by steps 3, 4 and 5 in the table below.
The following table shows the sequence of events during a typical DM session beginning with the initial session trigger sent as an alert message by the DM server.
Note
The step numbers in the table below do not represent message identification numbers (MsgID). All messages from the server must have a MsgID that is unique within the session, start at 1 for the first message, and increase by an increment of 1 for each additional message. For more information about MsgID and OMA SyncML protocol, see the OMA specification OMA Device Management Representation Protocol (OMA-TS-DM_RepPro-V1_2-20070209-A) available from the OMA Web site.
| Step | Action | Description |
|---|---|---|
1 |
The DM server sends an Alert to the client device. |
Using a WAP push, the DM server sends a Short Message Service (SMS) message to the device. The SMS message includes the server ID and tells the client device to initiate a session the server. The client device uses the server ID to verify that the server is authorized to communicate with it. |
2 |
The device sends a message, over an IP connection, to initiate the session. |
This message includes device information and credentials. |
3 |
The DM server responds, over an IP connection (HTTPS). |
The server sends its credentials and initial device management commands, if any. |
4 |
The device responds to server management commands. |
This message includes the results of performing the specified device management operations. |
5 |
The DM server terminates the session or sends another command. |
The DM session ends or repeat step 4. |
See Also
Concepts
Best Practices in Managing Devices