How the BlackBerry Attachment Connector communicates with BlackBerry Attachment Service instances

When a user sends a request to view an email message attachment on a BlackBerry device, the BlackBerry device sends a request to the BlackBerry Enterprise Server to convert the attachment. The BlackBerry Enterprise Server uses a BlackBerry Attachment Connector to send the attachment data to a BlackBerry Attachment Service, which processes the request and returns the attachment data to the BlackBerry Attachment Connector. The BlackBerry Enterprise Server requests the attachment data from the BlackBerry Attachment Connector and sends the attachment data to the user's BlackBerry device.

By associating multiple BlackBerry Attachment Service instances with a single BlackBerry Attachment Connector, you can create a BlackBerry Attachment Service pool. You can configure different BlackBerry Attachment Service instances as dedicated servers for processing specific file formats. For example, you can create a BlackBerry Attachment Service pool that contains three BlackBerry Attachment Service instances, where one instance processes email message attachments that are in audio file formats, one instance processes email message attachments that are in image file formats, and one instance processes email message attachments that are in all other file formats. For more information about configuring high availability for the BlackBerry Attachment Service, see the BlackBerry Enterprise Server Planning Guide.

You can change how a BlackBerry Attachment Connector processes attachment requests that it cannot deliver to a BlackBerry Attachment Service, and you can change how a BlackBerry Attachment Connector restores a lost connection to a BlackBerry Attachment Service.