You are previewing RTP: Audio and Video for the Internet.
O'Reilly logo
RTP: Audio and Video for the Internet

Book Description

The Real-time Transport Protocol (RTP) provides a framework for delivery of audio and video across IP networks with unprecedented quality and reliability. In RTP: Audio and Video for the Internet, Colin Perkins, a leader of the RTP standardization process in the IETF, offers readers detailed technical guidance for designing, implementing, and managing any RTP-based system.

By bringing together crucial information that was previously scattered or difficult to find, Perkins has created an incredible resource that enables professionals to leverage RTP's benefits in a wide range of Voice-over IP (VoIP) and streaming media applications. He demonstrates how RTP supports audio/video transmission in IP networks, and shares strategies for maximizing performance, robustness, security, and privacy.

Comprehensive, exceptionally clear, and replete with examples, this book is the definitive RTP reference for every audio/video application designer, developer, researcher, and administrator.

Key coverage includes:

  • RTP's goals, design philosophy, and relationships with other protocols

  • The psychology of human perception in the design of media delivery systems

  • RTP data transfer and control protocols, including framing, loss detection, reception quality feedback, and membership control

  • Media playout, timing, and synchronization, including lip synchronization

  • Mitigating network problems: error concealment, error correction, and congestion control

  • Optimizing performance over low-speed links: header compression, multiplexing, and tunneling

  • Integrating leading media codecs and standards into RTP systems

  • Securing RTP sessions: encryption, authentication, and the new secure RTP profile for wireless networks

  • Extensive references and practical examples throughout



  • 0672322498B05092003

  • Table of Contents

    1. Copyright
    2. Preface
      1. Introduction
      2. Organization of the Book
      3. Intended Audience
    3. Acknowledgments
    4. I. Introduction to Networked Multimedia
      1. 1. An Introduction to RTP
        1. A Brief History of Audio/Video Networking
          1. Early Packet Voice and Video Experiments
          2. Audio and Video on the Internet
          3. ITU Standards
          4. Audio/Video Streaming
        2. A Snapshot of RTP
        3. Related Standards
        4. Overview of an RTP Implementation
          1. Behavior of an RTP Sender
          2. Behavior of an RTP Receiver
        5. Summary
      2. 2. Voice and Video Communication Over Packet Networks
        1. TCP/IP and the OSI Reference Model
        2. Performance Characteristics of an IP Network
        3. Measuring IP Network Performance
          1. Average Packet Loss
          2. Packet Loss Patterns
          3. Packet Duplication
          4. Packet Corruption
          5. Network Transit Time
          6. Acceptable Packet Sizes
          7. Effects of Multicast
          8. Effects of Network Technologies
          9. Conclusions about Measured Characteristics
        4. Effects of Transport Protocols
          1. UDP/IP
          2. TCP/IP
        5. Requirements for Audio/Video Transport in Packet Networks
          1. Benefits of Packet-Based Audio/Video
        6. Summary
    5. II. Media Transport Using RTP
      1. 3. The Real-Time Transport Protocol
        1. Fundamental Design Philosophies of RTP
          1. Application-Level Framing
          2. The End-to-End Principle
          3. Achieving Flexibility
        2. Standard Elements of RTP
          1. The RTP Specification
          2. RTP Profiles
          3. RTP Payload Formats
          4. Optional Elements
        3. Related Standards
          1. Call Setup and Control
          2. Session Description
          3. Quality of Service
        4. Future Standards Development
        5. Summary
      2. 4. RTP Data Transfer Protocol
        1. RTP Sessions
        2. The RTP Data Transfer Packet
          1. Header Elements
            1. PAYLOAD TYPE
            2. SEQUENCE NUMBER
            3. TIMESTAMP
            4. SYNCHRONIZATION SOURCE
            5. CONTRIBUTING SOURCES
            6. MARKER
            7. PADDING
            8. VERSION NUMBER
          2. Header Extensions
          3. Payload Headers
          4. Payload Data
        3. Packet Validation
        4. Translators and Mixers
          1. Translators
          2. Mixers
        5. Summary
      3. 5. RTP Control Protocol
        1. Components of RTCP
        2. Transport of RTCP Packets
        3. RTCP Packet Formats
          1. RTCP RR: Receiver Reports
            1. THE RTCP RR PACKET FORMAT
            2. INTERPRETING RR DATA
          2. RTCP SR: Sender Reports
            1. THE RTCP SR PACKET FORMAT
            2. INTERPRETING SR DATA
          3. RTCP SDES: Source Description
            1. THE RTCP SDES PACKET FORMAT
            2. STANDARD SDES ITEMS
            3. PARSER ISSUES
          4. RTCP BYE: Membership Control
          5. RTCP APP: Application-Defined RTCP Packets
          6. Packing Issues
        4. Security and Privacy
        5. Packet Validation
        6. Participant Database
        7. Timing Rules
          1. Reporting Interval
          2. Basic Transmission Rules
          3. Forward Reconsideration
          4. Reverse Reconsideration
          5. BYE Reconsideration
          6. Comments on Reconsideration
          7. Common Implementation Problems
        8. Summary
      4. 6. Media Capture, Playout, and Timing
        1. Behavior of a Sender
        2. Media Capture and Compression
          1. Audio Capture and Compression
          2. Video Capture and Compression
          3. Use of Prerecorded Content
        3. Generating RTP Packets
          1. Timestamps and the RTP Timing Model
          2. Fragmentation
          3. Payload Format–Specific Headers
        4. Behavior of a Receiver
        5. Packet Reception
          1. Receiving Data Packets
          2. Receiving Control Packets
        6. The Playout Buffer
          1. Basic Operation
          2. Playout Time Calculation
            1. MAPPING TO THE LOCAL TIMELINE
            2. COMPENSATION FOR CLOCK SKEW
            3. COMPENSATION FOR SENDER BEHAVIOR
            4. COMPENSATION FOR JITTER
            5. COMPENSATION FOR ROUTE CHANGES
            6. COMPENSATION FOR PACKET REORDERING
        7. Adapting the Playout Point
          1. Playout Adaptation for Audio with Silence Suppression
          2. Playout Adaptation for Audio without Silence Suppression
          3. Playout Adaptation for Video
        8. Decoding, Mixing, and Playout
          1. Decoding
          2. Audio Mixing
          3. Audio Playout
          4. Video Playout
        9. Summary
      5. 7. Lip Synchronization
        1. Sender Behavior
        2. Receiver Behavior
        3. Synchronization Accuracy
        4. Summary
    6. III. Robustness
      1. 8. Error Concealment
        1. Techniques for Audio Loss Concealment
          1. Measuring Audio Quality
          2. Silence Substitution
          3. Noise Substitution
          4. Repetition
          5. Other Techniques for Repairing Speech Signals
        2. Techniques for Video Loss Concealment
          1. Motion-Compensated Repetition
          2. Other Techniques for Repairing Video Packet Loss
          3. Dependency Reduction
        3. Interleaving
        4. Summary
      2. 9. Error Correction
        1. Forward Error Correction
          1. Parity FEC
            1. FORMAT OF PARITY FEC PACKETS
            2. USE OF PARITY FEC
            3. RECOVERING FROM LOSS
          2. Unequal Error Protection
          3. Reed–Solomon Codes
          4. Audio Redundancy Coding
            1. FORMAT OF REDUNDANT AUDIO PACKETS
            2. LIMITATIONS OF REDUNDANT AUDIO
            3. USE OF REDUNDANT AUDIO
        2. Channel Coding
          1. Partial Checksum
          2. Reference Picture Selection
        3. Retransmission
          1. RTCP as a Framework for Retransmission
            1. PACKET FORMATS
            2. TIMING RULES
            3. MODES OF OPERATION
          2. Applicability
        4. Implementation Considerations
          1. At a Receiver
          2. At the Sender
        5. Summary
      3. 10. Congestion Control
        1. The Need for Congestion Control
        2. Congestion Control on the Internet
        3. Implications for Multimedia
        4. Congestion Control for Multimedia
          1. TCP-Like Rate Control
          2. TCP-Friendly Rate Control
          3. Layered Coding
        5. Summary
    7. IV. Advanced Topics
      1. 11. Header Compression
        1. Introductory Concepts
          1. Patterns, Robustness, and Local Implementation
          2. Standards
        2. Compressed RTP
          1. Operation of CRTP: Initialization and Context
          2. Operation of CRTP: Compression and Decompression
          3. Effects of Packet Loss
        3. Robust Header Compression
          1. Operation of ROHC: States and Modes
          2. Operation of ROHC: Robustness and Compression Efficiency
        4. Considerations for RTP Applications
        5. Summary
      2. 12. Multiplexing and Tunneling
        1. The Motivation for Multiplexing
        2. Tunneling Multiplexed Compressed RTP
          1. Basic Concepts of TCRTP
          2. Implementing TCRTP
          3. Performance
        3. Other Approaches to Multiplexing
          1. GeRM
            1. CONCEPTS AND PACKET FORMAT
            2. APPLICATION SCENARIOS
            3. THE FUTURE OF GERM
          2. Application-Specific Multiplexing
        4. Summary
      3. 13. Security Considerations
        1. Privacy
        2. Confidentiality
          1. Confidentiality Features in the RTP Specification
          2. Confidentiality Using the Secure RTP Profile
          3. Confidentiality Using IP Security
          4. Other Considerations
        3. Authentication
          1. Authentication Using Standard RTP
          2. Authentication Using the Secure RTP Profile
          3. Authentication Using IP Security
        4. Replay Protection
        5. Denial of Service
        6. Mixers and Translators
        7. Active Content
        8. Other Considerations
        9. Summary
    8. References
      1. IETF RFC Standards
      2. IETF Internet-Drafts
      3. Other Standards
      4. Conference and Journal Papers
      5. Books
      6. Web Sites
      7. Other References