For offering entertainment services by video streaming content to users, a
video encoder creates the required .nsc file for each broadcast channel.
This .nsc file is retrieved and stored on a server which notifies each
set-top box in the field, via a multicast notifier of the availability of
the new service. This notifier contains the multicast address and port to
where the .nsc files are being streamed. Once the set-top box retrieves
this notification, it attempts to join the dedicated multicast stream,
download the .nsc files and store them locally in memory on the set-top
box. When a user selects a broadcast channel from their lineup, the
set-top box will access the local file to obtain the proper information
about that particular ASF stream; hence, it will not have to do an HTTP
retrieval.