Bandwidth is a measurement that reflects the data transfer capacity of a network. Bandwidth is usually expressed in the number of bits that a system is capable of transferring in a second: bits per second (bps) or kilobits per second (Kbps). Windows Media Services utilizes the available network bandwidth when streaming content to clients. Each stream from your server has a bandwidth requirement. Clients that are connecting to your server have defined available bandwidth, based on their network connection method. Therefore, when planning your streaming media system, you must include support for different bandwidths. Multicasting streaming is one method that is commonly used to conserve bandwidth on intranets because it only sends a single stream across the network.