Audio Over IP. Building Pro AolP Systems. with Livewire. Skip Pizzi. Steve Church. Focal. Press ELSEVIER AMSTERDAM BOSTON HEIDELBERG LONDON

Transcription

1 Audio Over IP Building Pro AolP Systems with Livewire Steve Church Skip Pizzi ELSEVIER AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO Focal press is an imprint of Elsevier Focal Press

2 Contents Acknowledgements xv Preface CHAPTER 1 Introduction to AolP l 1.1 Two to Tango Arguments for AolP Scalability Cost Effectiveness Convenience Smooth Integration with Other IP-Based Systems Talking the PC's Native Language In the Tech Mainstream Future-proofing IP-Anything What's the Catch? Implementation and Integration AolP in Use Today The Bottom Line 11 CHAPTER 2 Network Engineering for Audio Engineers TDM versus IP Statistical Multiplexing IP "Backplane" Ethernet/IP Networks: Layering Model Layer 1: Physical Interface Layer 2: Ethernet and Switching Layer 3: IP Routing Layer 4: Transport Layer 5- Application Making Packets TCP UDP RTP Ports Local Area Networks Ethernet Switching 27 vii

3 viii Contents 23.2 Ethernet Traffic Prioritization The Role of TCP for Audio on LANs VLANs Ethernet Multicast IGMP ARP Wide Area Networks and the Internet The Internet Private WANs VPNs DNS DHCP IP Broadcast IP Multicast Firewalls NATs Quality of Service Bandwidth Dropped Packets Delay and Jitter Service Level Agreements MPLS IP and Ethernet Addresses IP Addresses Subnets and the Subnet Mask Ethernet Addresses Network Diagrams Pro-Audio, Meet IP 49 CHAPTER 3 Switching and Routing Layers and Terms Ethernet Switch Managed Switches Scalability IP Router Routes of the Internet TCP/IP Suite Straddling Layers Audio Routing Control Multicasting 59

4 Contents ix CHAPTER 4 Livewire System What Can You Do with It? AES Livewire System Components Axia Hardware Interface Nodes Router Selector Node GPIO Node Axia Driver for Windows iplay (PC Router Selector) Axia Element Mixing Console Pathfinder Routing Control Software Axia Intercom System Telos iport Codec Telos Nxl2 and Nx6 Telephone Interfaces Omnia 8x Dynamics Processor Fraunhofer Institute "Content Server" Encoders Channel Numbering and Naming Channel Numbers Text Name Sources and Destinations Backfeeds and Mix-Minus GPIO V-Mix and V-Mode Delay Levels and Metering Headroom Alignment International Variants Terminology of Audio Level Metering Livewire Levels Aligning Consoles to PC Audio Applications Deep Stuff How the Livewire Technology Works Quality of Service Source Advertising Synchronization Livewire's Use of Multicast Ethernet and IP Addresses Livewire Packet Format Link Capacity Network Time Protocol 106

5 x Contents Network Standards and Resources Livewire Routing Control Protocol Livewire Control Protocol 108 CHAPTER 5 Designing and Building with AolP Wiring the AolP Facility Simplification via Cabling Structured Wiring Ethernet for AolP Systems Twisted-Pair Cable Categories Structure of Structured Wiring Pin Numbering, Jacks, Cables, and Color Codes Installing RJ-45s Special Care for AolP Wiring Minimizing Pairs in a Cable Patch Panels Wall Jacks Power over Ethernet Fiber Beyond Cable: Ethernet Radio Links Analog and AES3 Audio Cabling Microphone Connections Unbalanced Connections Ethernet Switches and IP Routers for Livewire Switch Configuration AolP Applications and Architectures AolP "Snake" Networkable PC Sound Card Studio-to-Transmitter Link Simple Radio Studio Full-Fledged Radio Facility Livewire "Classic" Radio Studio Setup Audio Router A 50+ Studio Facility with Redundancy More on Architectures Daisy-Chaining l4l Redundancy Security 143

6 Contents xi CHAPTER 6 VoIP Telephone Systems in the Studio Environment VoIP in Radio Stations SIP Parts of a SIP System Addressing How SIP Works The State of SIP and Its Future IAX as a SIP Alternative Codecs Packetization and RTP Delay IP PBX Cisco Microsoft Asterisk Others Gateways Overview of Circuit-Switched Interfaces Using VoIP to Connect to the Telco Network MPLS IP Centrex and Hosted PBX Services Skype Studio On-Air Systems Line Echo Cancellation Audio Processing Acoustic Echo Cancellation Application Example: Telos VX System Application Examples: Telos Nx6 and Nxl Transformative Tech 190 CHAPTER 7 IP Codecs The Challenge When Delay Doesn't Matter When Delay Does Matter: Achieving Low Delay Audio Coding Transport Adaptive Receive Buffer Adaptive Codec Bitrate Putting It Together 196

7 xii Contents 7.4 Delay and Echo Call Setup: Say Hello to SIP (Again) SIP Servers Firewalls and NATs Telos Z/IP Server Networks Public Internet Dedicated Links MPLS Service Mobile IP Services Ethernet Radios WiMax WiEi Satellites EBU N/ACIP Standard Transport Protocols Audio Coding Signaling What's Missing from N/ACIP? Livewire-Enabled IP Codecs Telos Z/IP Telos iport Convergence 210 CHAPTER 8 Troubleshooting Prevention Basic Network Tests and Diagnostics Link Test Ping and TraceRoute Rate and Duplex Modes Ethernet Switch Diagnostics and Configuration Link, Activity, Duplex, and Rate LEDs Advanced Switch Diagnostics Switch Configuration Cable Testers Sniffers Livewire Components Livewire Node Network Status LEDs Checking Audio Levels 222

8 Contents xiii 8.7 Logging Element Console Pathfinder PC 224 CHAPTER 9 FAQs Reliability Cost Effectiveness Latency Interconnection Livewire-Specific Issues 236 References and Resources 241 Glossary of Acronyms 245 Index 253