OMA DM Client Connection Retry
4/8/2010
The OMA DM Client Connection Retry technology is used in remote device management with OMA DM version 1.2 to more reliably connect to the server. It also attempts to reconnect if the connection fails during a device management session.
The OMA DM client also attempts to reconnect at the HTTP level if one of the following HTTP status codes is received:
- 404 Not Found
- 408 Request Timeout
- 413 Request Entity Too Large
- 500 Internal Server Error
- 503 Service Unavailable
- 504 Gateway Timeout
Connection retry information, such as the retry frequency and the time to wait before attempting reconnection, is stored in the registry. Privileged applications and those with the MANAGER role can configure these settings.**
Each time the client attempts to reconnect, the wait time grows exponentially. For example, if the first wait time is 60 seconds, or 1 minute, then the wait time on the next connection attempt is 2 minutes, on the third attempt it is 4 minutes, and so forth. The DM client stops attempting to connect if the retry frequency is reached.
Note
If the first SMS message, the server trigger, has the UI Mode flag set for user interaction, then the DM client sends a message to the user's Inbox with the session results.
Scenario
The following steps describe a typical scenario for the OMA DM Client Connection Retry technology. In this example, the device is trying to send the OTA firmware update result back to the OMA DM server.
- The DM client calls Connection Manager to set up a GPRS data connection.
- Because the connection is not set up after one minute, the DM client calls Connection Manager again.The connection is set up after 20 seconds more.
- The DM client attempts to set up an HTTP connection.
- The server responds with the HTTP status code 503 Service Unavailable.
- The DM client calls HTTP again.
- The DM client waits for 1 minute, and then calls HTTP again.
- The DM client waits another 2 minutes, and then calls HTTP again.
- The connection succeeds.
Or, if the connection still fails, the connection is dropped and no further attempts to connect are made. - If the server trigger has the UI Mode flag set for user interaction, then the DM client sends a message to the user's Inbox with the session results.