Flash based applications connect to the hub using Real Time Messaging Protocol (RTMP). The server can send and receive data to and from the connected users with live web FLV player installed. Connected clients can make Remote procedure calls (RPC) on the server-side and the server can call methods on specific clients.
The server also allows users to receive and publish net streams. When viewing a net stream the user can either create their own to view a remotely stored Flash Video (FLV) or the server can instantiate a net stream and play a video on it, the latter method means that every user will be at the same point in the video when they subscribe to it as they are all viewing the same stream.
A Windows Media server is designed specifically for streaming on-demand and live digital media to clients. It provides high-quality streaming over a wide range of bandwidths to Windows Media Player and to Web browsers that use the Windows Media Player 9 Series ActiveX control or the Microsoft Silverlight browser plug-in. It is especially useful for streaming large amounts of data over busy, congested networks and low-bandwidth connections. Streaming uses bandwidth more efficiently than downloading because it sends data over the network only at the speed that is necessary for the client to render it correctly. This helps prevent the network from becoming overloaded and helps maintain system reliability.