What is server or protocol rollover?
Online content distributor can use metafiles (specially organized simple text files) to provide means of automatically switching to alternate content sources when a media stream cannot be accessed or played for some reason. This is called rollover, and you can use it to specify alternate content on different servers or even different types of servers. The simplest playlists are created by adding multiple ENTRY elements to a metafile. Concerning Windows Media streaming, you can specify a first alternate on a different Windows Media server. If that content fails to play, the client can rollover to a second alternate on a Web server. Windows Media Services 9 Series can use RTSP, HTTP, or MMS protocols for streaming. It uses RTSP when trying to connect to Windows Media Player 9 Series or later. If that attempt is unsuccessful, the server uses HTTP to connect to the Player. Earlier versions of the Player do not support RTSP, but they do support MMS protocol. If the server cannot connect to
