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Audio Over IP

Book Description

Position yourself at the forefront of audio and broadcast studio technology by learning audio over IP. You will gain knowledge of IP network engineering as it applies to audio applications, and then progress to a full understanding of how equipment built on Ethernet and Internet Protocol are used in today's audio production and broadcast facilities for the transporting, mixing and processing of pro-quality audio. A chapter on integrating Voice-over IP telephony (VoIP) to pro-audio and broadcast facilities is also included.

Using the popular Livewire technology, you will learn how to design, construct, configure and troubleshoot an AoIP system, including how to interface with PCs, VoIP telephone PBXs, IP codecs, and the Internet. See how AoIP systems work in practice, and discover their distinct advantages over older audio infrastructures. With its complete introduction to AoIP technology in a fun, highly readable style, this book is essential for audio professionals who want to broaden their knowledge of IP-based studio systems--or for IT experts who need to understand AoIP applications.



Table of Contents

  1. Front Cover
  2. Title Page
  3. Copyright
  4. Dedication
  5. Contents
  6. Acknowledgments
  7. Preface
  8. CHAPTER 1 Introduction to AoIP
    1. 1.1 Two to Tango
    2. 1.2 Arguments for AoIP
      1. 1.2.1 Scalability
      2. 1.2.2 Cost Effectiveness
      3. 1.2.3 Convenience
      4. 1.2.4 Smooth Integration with Other IP-Based Systems
      5. 1.2.5 Talking the PC’s Native Language
      6. 1.2.6 In the Tech Mainstream
      7. 1.2.7 Future-proofing
    3. 1.3 IP-Anything
    4. 1.4 What’s the Catch?
    5. 1.5 Implementation and Integration
    6. 1.6 AoIP in Use Today
    7. 1.7 The Bottom Line
  9. CHAPTER 2 Network Engineering for Audio Engineers
    1. 2.1 TDM versus IP
      1. 2.1.1 Statistical Multiplexing
      2. 2.1.2 IP “Backplane”
    2. 2.2 Ethernet/IP Networks: Layering Model
      1. 2.2.1 Layer 1: Physical Interface
      2. 2.2.2 Layer 2: Ethernet and Switching
      3. 2.2.3 Layer 3: IP Routing
      4. 2.2.4 Layer 4: Transport
      5. 2.2.5 Layer 5: Application
      6. 2.2.6 Making Packets
      7. 2.2.7 TCP
      8. 2.2.8 UDP
      9. 2.2.9 RTP
      10. 2.2.10 Ports
    3. 2.3 Local Area Networks
      1. 2.3.1 Ethernet Switching
      2. 2.3.2 Ethernet Traffic Prioritization
      3. 2.3.3 The Role of TCP for Audio on LANs
      4. 2.3.4 VLANs
      5. 2.3.5 Ethernet Multicast
      6. 2.3.6 IGMP
      7. 2.3.7 ARP
    4. 2.4 Wide Area Networks and the Internet
      1. 2.4.1 The Internet
      2. 2.4.2 Private WANs
      3. 2.4.3 VPNs
      4. 2.4.4 DNS
      5. 2.4.5 DHCP
      6. 2.4.6 IP Broadcast
      7. 2.4.7 IP Multicast
      8. 2.4.8 Firewalls
      9. 2.4.9 NATs
    5. 2.5 Quality of Service
      1. 2.5.1 Bandwidth
      2. 2.5.2 Dropped Packets
      3. 2.5.3 Delay and Jitter
      4. 2.5.4 Service Level Agreements
      5. 2.5.5 MPLS
    6. 2.6 IP and Ethernet Addresses
      1. 2.6.1 IP Addresses
      2. 2.6.2 Subnets and the Subnet Mask
      3. 2.6.3 Ethernet Addresses
    7. 2.7 Network Diagrams
    8. 2.8 Pro-Audio, Meet IP
  10. CHAPTER 3 Switching and Routing
    1. 3.1 Layers and Terms
    2. 3.2 Ethernet Switch
      1. 3.2.1 Managed Switches
      2. 3.2.2 Scalability
    3. 3.3 IP Router
      1. 3.3.1 Routes of the Internet
      2. 3.3.2 TCP/IP Suite
    4. 3.4 Straddling Layers
    5. 3.5 Audio Routing Control
    6. 3.6 Multicasting
  11. CHAPTER 4 Livewire System
    1. 4.1 What Can You Do with It?
    2. 4.2 AES3
    3. 4.3 Livewire System Components
      1. 4.3.1 Axia Hardware Interface Nodes
      2. 4.3.2 Router Selector Node
      3. 4.3.3 GPIO Node
      4. 4.3.4 Axia Driver for Windows
      5. 4.3.5 iPlay (PC Router Selector)
      6. 4.3.6 Axia Element Mixing Console
      7. 4.3.7 Pathfinder Routing Control Software
      8. 4.3.8 Axia Intercom System
      9. 4.3.9 Telos iPort Codec
      10. 4.3.10 Telos Nx12 and Nx6 Telephone Interfaces
      11. 4.3.11 Omnia 8x Dynamics Processor
      12. 4.3.12 Fraunhofer Institute “Content Server” Encoders
    4. 4.4 Channel Numbering and Naming
      1. 4.4.1 Channel Numbers
      2. 4.4.2 Text Name
      3. 4.4.3 Sources and Destinations
      4. 4.4.4 Backfeeds and Mix-Minus
      5. 4.4.5 GPIO
      6. 4.4.6 V-Mix and V-Mode
    5. 4.5 Delay
    6. 4.6 Levels and Metering
      1. 4.6.1 Headroom
      2. 4.6.2 Alignment
      3. 4.6.3 International Variants
      4. 4.6.4 Terminology of Audio Level Metering
      5. 4.6.5 Livewire Levels
      6. 4.6.6 Aligning Consoles to PC Audio Applications
    7. 4.7 Deep Stuff—How the Livewire Technology Works
      1. 4.7.1 Quality of Service
      2. 4.7.2 Source Advertising
      3. 4.7.3 Synchronization
      4. 4.7.4 Livewire’s Use of Multicast Ethernet and IP Addresses
      5. 4.7.5 Livewire Packet Format
      6. 4.7.6 Link Capacity
      7. 4.7.7 Network Time Protocol
      8. 4.7.8 Network Standards and Resources
    8. 4.8 Livewire Routing Control Protocol
    9. 4.9 Livewire Control Protocol
  12. CHAPTER 5 Designing and Building with AoIP
    1. 5.1 Wiring the AoIP Facility
      1. 5.1.1 Simplification via Cabling
      2. 5.1.2 Structured Wiring
      3. 5.1.3 Ethernet for AoIP Systems
      4. 5.1.4 Twisted-Pair Cable Categories
      5. 5.1.5 Structure of Structured Wiring
      6. 5.1.6 Pin Numbering, Jacks, Cables, and Color Codes
      7. 5.1.7 Installing RJ-45s
      8. 5.1.8 Special Care for AoIP Wiring
      9. 5.1.9 Minimizing Pairs in a Cable
      10. 5.1.10 Patch Panels
      11. 5.1.11 Wall Jacks
      12. 5.1.12 Power over Ethernet
      13. 5.1.13 Fiber
      14. 5.1.14 Beyond Cable: Ethernet Radio Links
      15. 5.1.15 Analog and AES3 Audio Cabling
      16. 5.1.16 Microphone Connections
      17. 5.1.17 Unbalanced Connections
    2. 5.2 Ethernet Switches and IP Routers for Livewire
      1. 5.2.1 Switch Configuration
    3. 5.3 AoIP Applications and Architectures
      1. 5.3.1 AoIP “Snake”
      2. 5.3.2 Networkable PC Sound Card
      3. 5.3.3 Studio-to-Transmitter Link
      4. 5.3.4 Simple Radio Studio
      5. 5.3.5 Full-Fledged Radio Facility
      6. 5.3.6 Livewire “Classic” Radio Studio Setup
      7. 5.3.7 Audio Router
      8. 5.3.8 A 50+ Studio Facility with Redundancy
    4. 5.4 More on Architectures
      1. 5.4.1 Daisy-Chaining
      2. 5.4.2 Redundancy
      3. 5.4.3 Security
  13. CHAPTER 6 VoIP Telephone Systems in the Studio Environment
    1. 6.1 VoIP in Radio Stations
    2. 6.2 SIP
      1. 6.2.1 Parts of a SIP System
      2. 6.2.2 Addressing
      3. 6.2.3 How SIP Works
      4. 6.2.4 The State of SIP and Its Future
    3. 6.3 IAX as a SIP Alternative
    4. 6.4 Codecs
    5. 6.5 Packetization and RTP
    6. 6.6 Delay
    7. 6.7 IP PBX
      1. 6.7.1 Cisco
      2. 6.7.2 Microsoft
      3. 6.7.3 Asterisk
      4. 6.7.4 Others
    8. 6.8 Gateways
      1. 6.8.1 Overview of Circuit-Switched Interfaces
    9. 6.9 Using VoIP to Connect to the Telco Network
      1. 6.9.1 MPLS
      2. 6.9.2 IP Centrex and Hosted PBX Services
    10. 6.10 Skype
    11. 6.11 Studio On-Air Systems
      1. 6.11.1 Line Echo Cancellation
      2. 6.11.2 Audio Processing
      3. 6.11.3 Acoustic Echo Cancellation
      4. 6.11.4 Application Example: Telos VX System
    12. 6.12 Application Examples: Telos Nx6 and Nx12
    13. 6.13 Transformative Tech
  14. CHAPTER 7 IP Codecs
    1. 7.1 The Challenge
    2. 7.2 When Delay Doesn’t Matter
    3. 7.3 When Delay Does Matter: Achieving Low Delay
      1. 7.3.1 Audio Coding
      2. 7.3.2 Transport
      3. 7.3.3 Adaptive Receive Buffer
      4. 7.3.4 Adaptive Codec Bitrate
      5. 7.3.5 Putting It Together
    4. 7.4 Delay and Echo
    5. 7.5 Call Setup: Say Hello to SIP (Again)
    6. 7.6 SIP Servers
      1. 7.6.1 Firewalls and NATs
      2. 7.6.2 Telos Z/IP Server
    7. 7.7 Networks
      1. 7.7.1 Public Internet
      2. 7.7.2 Dedicated Links
      3. 7.7.3 MPLS Service
      4. 7.7.4 Mobile IP Services
      5. 7.7.5 Ethernet Radios
      6. 7.7.6 WiMax
      7. 7.7.7 WiFi
      8. 7.7.8 Satellites
    8. 7.8 EBU N/ACIP Standard
      1. 7.8.1 Transport Protocols
      2. 7.8.2 Audio Coding
      3. 7.8.3 Signaling
      4. 7.8.4 What’s Missing from N/ACIP?
    9. 7.9 Livewire-Enabled IP Codecs
      1. 7.9.1 Telos Z/IP
      2. 7.9.2 Telos iPort
    10. 7.10 Convergence
  15. CHAPTER 8 Troubleshooting
    1. 8.1 Prevention
    2. 8.2 Basic Network Tests and Diagnostics
      1. 8.2.1 Link Test
      2. 8.2.2 Ping and TraceRoute
      3. 8.2.3 Rate and Duplex Modes
    3. 8.3 Ethernet Switch Diagnostics and Configuration
      1. 8.3.1 Link, Activity, Duplex, and Rate LEDs
      2. 8.3.2 Advanced Switch Diagnostics
      3. 8.3.3 Switch Configuration
    4. 8.4 Cable Testers
    5. 8.5 Sniffers
    6. 8.6 Livewire Components
      1. 8.6.1 Livewire Node Network Status LEDs
      2. 8.6.2 Checking Audio Levels
    7. 8.7 Logging
      1. 8.7.1 Element Console
      2. 8.7.2 Pathfinder PC
  16. CHAPTER 9 FAQs
    1. 9.1 Reliability
    2. 9.2 Cost Effectiveness
    3. 9.3 Latency
    4. 9.4 Interconnection
    5. 9.5 Livewire-Specific Issues
  17. References and Resources
  18. Glossary of Acronyms
  19. Index