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Packet Guide to Voice over IP

Book Description

Go under the hood of an operating Voice over IP network, and build your knowledge of the protocols and architectures used by this Internet telephony technology. With this concise guide, you’ll learn about services involved in VoIP and get a first-hand view of network data packets from the time the phones boot through calls and subsequent connection teardown.

Table of Contents

  1. Special Upgrade Offer
  2. Preface
    1. Audience
    2. Contents of This Book
    3. Conventions Used in This Book
    4. Using Code Examples
    5. Safari® Books Online
    6. How to Contact Us
    7. Acknowledgments
    8. Dedication
  3. 1. Introduction to Voice over the Internet Protocol
    1. What Is VoIP?
    2. Real-time Versus Nonreal-time Data
    3. Why Change to VoIP?
      1. The Business Case
    4. VoIP and FCC Regulation
      1. 911
      2. A Note on Power
    5. General VoIP Topologies
    6. Power over Ethernet
      1. PoE Basic Operation
    7. VoIP Protocols
      1. Signaling Protocols
        1. Session Initiation Protocol
        2. H.323
        3. Skinny Client Control Protocol
      2. Transport Protocol
    8. VoIP Basic Operation
      1. Performance
    9. Unified Communications
    10. Summary
    11. Standards and Reading
    12. Review Questions
    13. Review Question Answers
    14. Lab Activities
      1. Activity 1—Review of the Standards
      2. Activity 2—Download Wireshark and the Capture Files for This Chapter
      3. Activity 3—Examine VoIP Offerings in Your Area
      4. Activity 4—Take a Look at the FCC Website
      5. Activity 5—Latency, Packet Loss, and Jitter
  4. 2. Traditional Telephony
    1. Introduction
    2. Overview
    3. Organizations
    4. Connecting to the Traditional World
    5. Telecommunication Companies
    6. Telephone Wiring
      1. Data Cabling, EIA568 A and B
      2. POTS and the Local Loop
      3. T-1
        1. T-1 signaling
        2. T-1 physical layer and wiring
    7. Integrated Services Digital Network
    8. Basic Telephone-Call Operation
    9. Summary
    10. Standards and Reading
    11. Review Questions
    12. Review Question Answers
    13. Lab Activities
      1. Activity 1—Review Your Local Telephone Connections
      2. Activity 2—Experiment with the Desktop Telephone or VoIP Phone
      3. Activity 3—Wiring to the PBX or Central Office
      4. Activity 4—ITU-T Recommendations
  5. 3. Session Initiation Protocol
    1. Introduction
    2. Protocol Description
      1. Components
      2. Addressing
    3. Basic Operation
    4. SIP Messages and Message Structure
      1. Requests
      2. Responses
      3. Header Fields
    5. Basic Operation Continued
      1. Session Description Protocol (SDP)
    6. Trunks
    7. Security
    8. Summary
    9. Standards and Reading
    10. Review Questions
    11. Review Question Answers
    12. Lab Activities
      1. Activity 1—Build the Topology Shown
      2. Activity 2—Packet Capture
      3. Activity 3—Packet Capture Analysis
      4. Activity 4—Phone-Call Analysis
      5. Activity 5—SDP
  6. 4. The Real-Time Transport Protocol and the Real-Time Control Protocol
    1. Protocol Description
    2. Profiles
    3. Basic Operation
      1. Protocol Structure
        1. Header first octet
        2. Header second octet
        3. Packet fields beyond the first two octets
        4. RTP extension header
    4. RTP Control Protocol
      1. Detailed Operation
    5. Security
      1. Vectors
      2. SRTP Operation
    6. Summary
    7. Standards and Reading
    8. Review Questions
    9. Review Answers
    10. Lab Activities
      1. Activity 1—Topology Build
      2. Activity 2—Analysis of the RTP Stream
      3. Activity 3—The Codec
      4. Activity 4—Analysis of the RTCP Stream
  7. 5. Codecs
    1. Audio Frequencies
    2. Voice Signals
    3. Audio Coders and Decoders
      1. Sampling
      2. Quantizing
      3. ITU-T G Series Specifications
      4. Codec Selection and Performance
        1. So, what values can we expect?
    4. Transcoding
    5. Packet Loss and Packet Loss Concealment (PLC)
    6. What Codec Are You Using?
    7. Video Signals
      1. Sending a Series of Pictures
      2. Video Encoding
    8. Standards Groups for Video
      1. Profiles
      2. ITU-T Video Recommendations
      3. ISO/IEC Video Standards
    9. Summary
    10. Standards and Reading
    11. Review Questions
    12. Review Question Answers
    13. Lab Activities
      1. Activity 1—Colors
      2. Activity 2—File Sizes
      3. Activity 3—Audio Quality
      4. Activity 4—Video Quality
  8. 6. H.323 ITU-T Recommendation for Packet-Based Multimedia Communications Systems
    1. Recommendation Description
    2. Subprotocols
    3. Basic Operation and Message Structure
    4. H.225 Messaging
      1. Q.931 Fields
      2. H.225 Message Format
      3. H.225 RAS
        1. H.225 RAS fields
      4. H.225 Standard Messages
      5. H.225 Modes
        1. FastStart
      6. Other H.225 Messages
    5. H.245
    6. Voice Data
    7. Termination
    8. Summary
    9. Standards and Reading
    10. Review Questions
    11. Review Question Answers
    12. Lab Activities
      1. Activity 1—Build the Topology Shown
      2. Activity 2—Capture Setup
      3. Activity 3—Packet Capture Analysis
      4. Activity 4—Phone-Call Analysis
      5. Activity 5—H.245
  9. 7. Skinny Client Control Protocol
    1. Protocol Description
      1. Structure
      2. Basic Header Format
    2. Topology Construction
    3. Operational Stages
      1. Startup
      2. Registration
      3. Picking up the Handset—Going Off-Hook
      4. Dialing a Number
      5. At the Receiver
      6. Back at the Source Phone
      7. Voice Data
      8. Teardown of the Call
    4. Performance Measuring
    5. Off-Site Calling
    6. Summary
    7. Reading
    8. Review Questions
    9. Review Answers
    10. Lab Activities
      1. Activity 1—Basic Topology Build
      2. Activity 2—Going Off-Hook
      3. Activity 3—Show and Debug
      4. Activity 4—Call-Flow Diagram
      5. Activity 5—Multiple Call Managers
  10. About the Author
  11. Colophon
  12. Special Upgrade Offer
  13. Copyright