BlackBerry MDS Connection Service
The BlackBerry MDS Connection Service controls the flow of content that is sent to the BlackBerry device. This flow control allows the BlackBerry MDS Connection Service to minimize the amount of content that is sent over the wireless network, and can help to reduce the impact of pushing content to BlackBerry devices that are out of wireless coverage area, turned off, or otherwise unavailable.
Controlling the flow of content
The BlackBerry MDS Connection Service sends content to each BlackBerry device specified in the push request as a series of packets. To control the flow of pushed content, the BlackBerry MDS Connection Service initially sends a maximum of five packets. The BlackBerry MDS Connection Service doesn't send additional packets until the BlackBerry device returns an acknowledgment that the initial packets were received.
If the BlackBerry MDS Connection Service is unable to immediately deliver the packets to a BlackBerry device (for example, because the BlackBerry device is outside a wireless coverage area or is turned off), the packets are queued, and the BlackBerry MDS Connection Service tries to resend them later. If the BlackBerry MDS Connection Service is unable to deliver the packets before the flow control timeout is reached, then the packets are removed from the queue, and the push request is considered unsuccessful for the device. By default, the flow control timeout is 10 minutes.
Changing the size of packets and flow control timeout
Administrators can change the default size of the data packets and the default flow control timeout. Increasing the default size of the data packets requires more memory to store data in the queue, which can affect the performance of the BlackBerry MDS Connection Service. Increasing the flow control timeout means that push requests are queued in memory longer.
If the administrator limits the number of queued push connections, the push requests remain in the queue longer. This approach causes the BlackBerry MDS Connection Service to run out of available push connections, and could force the BlackBerry MDS Connection Service to deny future push requests.
Poke and pull
The push content limit is 8 KB, but you can use a poke and pull mechanism for any content over this limit. Poke and pull is a technique where a URL is pushed to the device in a short message (poke), and the device retrieves the content at the URL (pull). You can host unlimited content on the enterprise web servers that the apps can retrieve when they receive the poke.
Supported push formats
The push format that you use for push requests affects the format in which the delivery parameters are specified and how the content is packaged within the POST request.
The BlackBerry MDS Connection Service supports the following push formats.
PAP push format
The push request contains a MIME multipart message that includes two components: an XML-based PAP control entity that defines the delivery parameters, and the content to be pushed.
The PAP push format is an open standard developed by the Open Mobile Alliance. The BlackBerry MDS Connection Service supports the WAP PAP 2.0 standard.
BlackBerry push format
The push request sends the push content as a byte stream. The destination, based on parameters set by the ApplicationID, is specified within the URL of the push content. The destination users and other delivery parameters are specified in HTTP headers included with the request.
The BlackBerry push format is a proprietary push format supported exclusively by the BlackBerry MDS Connection Service and BlackBerry devices.
Storing push requests
You can store push requests in the BlackBerry Configuration Database. Administrators can configure the storage settings for push requests that are stored in the BlackBerry Configuration Database. The settings include the maximum number and maximum age of push requests stored in the database. When you implement a push solution, you should develop standards for these configuration settings.
For more information about configuring the BlackBerry Configuration Database, see the BlackBerry Device Service Administration Guide.
Last modified: 2015-06-11