It is possible to stream Real Audio/Video content from virtual servers hosted by Nexus via HTTP.
To organize real-time playback of RealAudio content, it is necessary to create a "metafile" (AKA stream definition file) for every content file deployed and point all links to these metafiles rather than to content files directly.
When a site visitor clicks on the link, the metafile is instantly downloaded and opened by the visitor's default media player, which starts pulling the content from the server.
The metafile format is very simple - at minimum the file would contain an exact URL of the media file on the server. (metafile extension should be .ram for real media and .asx for MS media player)
Please follow the link below for details on .asx file format: Windows Media Metafile Reference (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmplay/mmp_sdk/windowsmediametafilereference.asp)