Process flow: Viewing a message attachment
- A user receives a message with an attachment on a BlackBerry® device.
- The BlackBerry Messaging Agent verifies that the format of the attachment is valid for conversion.
- The user clicks the Open Attachment menu item to view the attachment on the BlackBerry device.
- The attachment viewer sends the request to the BlackBerry Messaging Agent.
- The BlackBerry Messaging Agent connects to the BlackBerry Attachment Service over port 1900.
- The BlackBerry Attachment Service retrieves the attachment in binary format from the user’s message store using the BlackBerry Messaging Agent link to the messaging server.
The BlackBerry Attachment Service formats the attachment for the BlackBerry device and converts it to UCS format. The formatting is based on the request for content (for example, page and paragraph information, or search words) and the available BlackBerry device information (for example, screen size, display, or available space).
- The BlackBerry Messaging Agent sends the converted attachment to the BlackBerry Dispatcher.
- The BlackBerry Dispatcher compresses the first portion of the attachment, encrypts it using the device transport key of the BlackBerry device, and sends the first portion of the attachment to the BlackBerry Router.
- The BlackBerry Router sends the first portion of the attachment to the wireless network over port 3101.
- The wireless network verifies that the PIN belongs to a valid BlackBerry device that is registered with the wireless network.
- The wireless network delivers the attachment to the BlackBerry device.
- The BlackBerry device sends a delivery confirmation to the BlackBerry Dispatcher, which sends it to the BlackBerry Messaging Agent. If the BlackBerry® Enterprise Server does not receive a delivery confirmation within 4 hours, it sends the attachment data to the wireless network again.
- The BlackBerry device uses its device transport key to decrypt and decompress the attachment so that the user can view the attachment.
- The user views the attachment on the BlackBerry device by selecting a section from the table of contents, or by viewing the full attachment. The original formatting of the attachment, including indents, tables, fonts, and bullets, is reflected on the BlackBerry device.