Starting with e-mail and web sites, the progression of Internet applications has continued to other areas such as streaming audio and video, which have larger and more consistent bandwidth requirements, and are more sensitive to network impairments. Even though the quality of video viewed on the Internet today is considerably inferior to that on television, the growth of streaming media has been phenomenal because of the ease of access. The applications include news clips, commercials and live events broadcasting. In addition, businesses often use streaming videos to enhance their enterprise communications with employees around the world. The streaming media application works by creating an encoded file and making it available on a streaming media server. Viewers can access the file over the Internet and play it on the client machine. The quality of streamed video is determined mainly by how the video was created (use of the camera), how it was encoded (choice of encoding parameters), and what the network impairments were at the time of playing the streamed video. Streaming media players help capture performance data that can be used to assess the service performance after processing the captured data. Streaming media performance can be viewed in the QoS-Technical Quality matrix covering the accessibility, continuity and fulfilment measures. The service performance can then be expressed as DPM charts to monitor performance trends over time, as well as daily exceptions.
Quality of Service for real-time Internet applications, Page 1 of 2
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