计算机网络自顶向下方法第四版Chapter7_4e.ppt

Chapter 7Multimedia Networking A note on the use of these ppt slides: We’re making these slides freely available to all (faculty, students, readers). They’re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: If you use these slides (e.g., in a class) in substantially unaltered form, that you mention their source (after all, we’d like people to use our book!) If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material. Thanks and enjoy! JFK / KWR All material copyright 1996-2007 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 4th edition. Jim Kurose, Keith RossAddison-Wesley, July 2007.  Multimedia and Quality of Service: What is it? multimedia applications: network audio and video (“continuous media”) Chapter 7: goals Principles classify multimedia applications identify network services applications need making the best of best effort service Protocols and Architectures specific protocols for best-effort mechanisms for providing QoS architectures for QoS Chapter 7 outline 7.1 multimedia networking applications 7.2 streaming stored audio and video 7.3 making the best out of best effort service 7.4 protocols for real-time interactive applications RTP,RTCP,SIP 7.5 providing multiple classes of service 7.6 providing QoS guarantees MM Networking Applications Fundamental characteristics: typically delay sensitive end-to-end delay delay jitter loss tolerant: infrequent losses cause minor glitches antithesis of data, which are loss intolerant but delay tolerant. Classes of MM applications: 1) stored streaming 2) live streaming 3) interactive, real-time Jitter is the variability of packet delays within the same packet stream Str