Glossary of Streaming Terms

asx: A file that points to a Windows Media audio stream.

Bandwidth: The amount of data that can be transmitted in a fixed amount of time. For streaming, bandwidth is usually expressed in bits per second.

Bit: The smallest unit of information, a 0 or a 1.

Bit rate: The speed at which data travels from one place to another on a computer network, such as the Internet. We stream 20 kpbs (kilobits) per second so that the widest range of users can listen. Stations stream about 9 (8.78 MB to be more exact) megabytes per hour.

Buffer: Space allocated on a system's RAM where data is temporarily stored until it is transferred to another part of the system. In streaming applications, buffers store video or audio data until there is enough information to start a complete stream.

Buffering: A situation that occurs when a streaming media player is saving portions of a streaming media file to local storage for playback. Most streaming players buffer a small percentage of a streaming media presentation before beginning to play it. Buffering also may occur in the middle of a stream, when adequate bandwidth is not available.

Cache: A technique used to save memory by storing frequently accessed files. Web browsers also have caches that keep downloaded Web pages handy, often as a list of links on the browser's toolbar. Browser caches are typically kept on local hard drive, and you can usually adjust the amount of memory or disk space allotted for the cache. You can access a cached page much more quickly than if you downloaded it from distant server.

Codec (compression-decompression): Standard method of compressing and decompressing data, typically done with audio/video files, or when data is encoded or compressed to reduce file size. A codec allows an operating system or a program to properly play audio or video in a particular format.

Distributed network: A network of multiple servers that can serve the same content. As a result, listeners receive content faster, with fewer interruptions and less down-time. For example, our streaming provider has a distributed network of 6000 streaming servers available for streaming audio.

Embedded Media: Media/media links that can be included in an HTML page, such as Windows Media streams, RealAudio files or GIF animations. Our custom player includes an embedded media player.

Encoder: Hardware or software application used to compress audio and video signals for streaming.

Hits: Hits are the individual requests a server. For audio, if one user requests the stream 3 times in a row, that counts as three hits in our current reporting.

Kbps (Kilobits per second): A rate at which data is sent over a communication line. We stream at 20 kbps.

MP3: A compression format that creates files that can be easily sent or downloaded across the Internet. MP3 is the MPEG audio layer 3 standard. CD tracks can be converted to MP3 and reduced in size by a factor of 12.

Net congestion: A situation that occurs when there is significant and unexpected delay between the server's transmission of data and the client's reception of data.

On-demand audio: A discrete piece of programming that is available when you want it, instead of when a broadcaster wants to send it.

Packet loss: Delay or loss of packets in a transmission, usually caused by a slow or congested network. Packet loss causes breaks or hiccups in data, resulting in audio gaps or video distortion.

Plug-ins: Software modules (aka files) that add a specific feature or service to a larger system (aka your browser). For example, the Windows Media plug-ins for the Netscape Navigator and Internet Explorer browsers enable them to handle streaming audio.

Real Audio: Describes a file format for audio-only streaming media technology released by RealNetworks, a leading streaming media platform vendor.

Streaming Media: Streaming media technology enables the real time or on demand distribution of audio, video and multimedia on the Internet. Streaming media is the simultaneous transfer of digital media (video, voice and data) so that it is received as a continuous real-time stream. A streamed file is simultaneously downloaded and viewed, but leaves behind no physical file on the viewer's machine. Rather than download a big, chunky audio/video file all at once, streaming allows you to see and hear an audio/video file as it's transferred. Windows Media, RealNetworks, and QuickTime are currently the three most popular streaming media platforms.

Unicast: A process that forces each individual user to make an individual connection to a server to receive a stream. This is how we currently stream.

Windows Media: The streaming media platform released by Microsoft.