Push model: Playing your media on an AirPlay device

In "Two models - push or pull?" we describe two populate models for playing the media that is stored on your iTunes server running iHomeServerâ„¢.  This topic describes the 'push model'.  See here for further information on the "pull" model.
As discussed, iTunes has the ability to AirPlay music and video to one or more devices simultaneously (NB video to only one other device at a time).  When coupled with the Apple Remote App which allows you to choose which media to play and which AirPlay device to send media to, you have access to an extremely powerful integrated audio/video network; and one that is controllable from any iPhone, iPad or iPod Touch device:
The above shows an example set up for using the Push Model.  iTunes and iHomeServer are installed on your Windows server.  The server may have its own sound card.  Watch Folders have been configured that have imported all the media on your server into your iTunes library.  iTunes has been configured to share its library via Home Sharing.  On the same wifi network, you may have AirPlay Speakers (such as the Loewe Air Speakers or the B&W Zeppelin speaker) in one room.  You may also have an AirPort Express on the same network with its audio line-out jack plugged into your non-Wifi enabled Hi-fi in the bedroom.  Finally you may also have an Apple TV on the network connected to your television via HDMI.
You have an iPhone, iPad or iPod Touch with the Apple Remote App installed; it has also been configured with the Home Sharing User ID and Password you entered when you configured Home Sharing within iTunes.  When you launch this app, you will see an icon with the name of the iTunes library you are running on your server.  When you tap the library name, you will be able to see the library's contents - both audio files and video files.  Selecting a track will start to play the media on the server itself.  By default, it will start to play through the local sound card, however, you can press the AirPlay icon ( ) to bring up a list of the AirPlay compatible devices on your network - this should show your AirPlay Speakers, AirPort Express and Apple TV - all of which you can name with descriptive labels.  Select the AirPlay device you want to route the media to.  If you are playing audio, you will be able to select multiple devices with the 'Multiple Speaker' option within the AirPlay menu.
Note that with the 'Push' model, as we describe it above, cannot be used to play audio or video on your iPhone/iPad/iPod Touch device.  Instead your device is being used   as a fancy remote control to control iTunes running on your server.  The media never gets to your device - which is useful to note as switching your device off does not interrupt media playback.  If, however, you wish to play media from your server on your iPhone/iPad/iPod Touch device, the next model (the 'Pull' model) is applicable.