General Recommendations

This topic lists recommendations that, if followed, will help ensure that your authoring tool generates and broadcasts ATVEF enhancements that display correctly on clients.

• Test the enhancements generated by your authoring tools on the slowest client platform your viewers will be using. This is necessary because the time needed to perform many of the steps involved in displaying the enhancement, such as setting up package reception and unpacking files, depends on the speed of the client. By testing the speed on the slowest client, you will be able to adjust the timing of enhancement transmissions so that all clients will have sufficient time to process and correctly display the enhancement.
• You should throttle packets when broadcasting. This is because the client has a limited number of receive buffers. If the client cannot recycle those buffers fast enough to keep up with the incoming data, the client will miss packets. This problem is especially apparent on high-speed networks.

  Data throttling is automatic if you use the ATVEFSnd.dll to transmit enhancements. ATVEFSnd.dll throttles package and trigger transmissions to the values specified in the announcement fields.

• If clients are not receiving all of the enhancement data transmitted, you may be sending the packets at too fast a bit rate for the client to receive. This problem may happen continuously, or in bursts of increased transmission rates.
• The ATVEF specification defines a tve-trigger control that receives and handles triggers. This control must appear in one of the content windows of your enhancement at all times, preferably in the base page. If this control is not present in your enhancement, triggers will not be handled by the client. If your enhancement navigates away from the page containing the tve-trigger control, the trigger which navigates away from the enhancement when the show ends will not be processed. If this occurs, the only way to exit your enhancement is for the user to manually turn off interactive content on the client. In WebTV for Windows, the tve-trigger control is implemented as the Trigger Receiver control.
• Your authoring tool should provide a way for users to customize data rates and the intervals between transmissions. This enables users to configure the enhancement so that it displays correctly on the targeted client platforms and network interfaces.
• Use uncompressed headers when sending announcements and triggers. If your application generates announcements and triggers using the methods exposed by ATVEFSnd.dll, this is handled automatically.