The Essential Guide To Audio OverIP FOR BROADCASTERS Powerful Performance | Powerful Control | Powerful Savings i 1. Why IP for Broadcast Audio? Reasons to Migrate to Audio over IP ..........................................................................................................8 1. Flexibility ..................................................................................................................................................................................8 2. Cost ...........................................................................................................................................................................................8 3. Scalability ................................................................................................................................................................................9 4. Reliability (yes really!) .........................................................................................................................................................9 5. Availability ..............................................................................................................................................................................9 6. Control and Monitoring .....................................................................................................................................................9 7. Network Consolidation ......................................................................................................................................................9 8. Potential Cost Savings from Switching from T1 to IP ............................................................................................. 10 9. Skills Consolidation ........................................................................................................................................................... 10 10. Necessity! .............................................................................................................................................................................. 11 CONTENTS 2. IP Audio Applications Studio Transmitter Links ............................................................................................................................................................... 12 Remotes / Outside Broadcasts .................................................................................................................................................... 13 Audio Contribution & Distribution ............................................................................................................................................ 13 Confidence Monitoring ................................................................................................................................................................. 14 3. The Nature of Audio Over IP 1. Packets and Packet Size ................................................................................................................................................... 15 2. Bandwidth,Compression & Compromise Framed Algorithms .......................................................................... 15 3. Audio Algorithms .............................................................................................................................................................. 17 New Audio Formats and Algorithms ....................................................................................................................................... 19 Opus ................................................................................................................................................................................................... 19 AES67 .................................................................................................................................................................................................. 20 4. About IP Networks Types of IP Networks .........................................................................................................................................21 Dedicated IP Links .................................................................................................................................................................. 21 MPLS Links ................................................................................................................................................................................ 21 Wireless IP Links ...................................................................................................................................................................... 22 Satellite IP .................................................................................................................................................................................. 22 Public Internet ......................................................................................................................................................................... 22 Types of Connections IP Address ................................................................................................................................................................24 Gateway ...................................................................................................................................................................24 Mask ..........................................................................................................................................................................24 1. Dealing with Jitter ...........................................................................................................................................24 2. Dealing with Delay .........................................................................................................................................25 3. Packet Loss .........................................................................................................................................................26 The Essential Guide To Audio Over IP for Broadcasters 2 5. Overcoming Imperfections a. Concealment ........................................................................................................................................................................ 27 b. Forward Error Correction ................................................................................................................................................ 27 c. Quality of Service ............................................................................................................................................................... 29 d. Service Level Agreements .............................................................................................................................................. 30 e. Alternative Connection .................................................................................................................................................... 30 f. Redundant Streaming ....................................................................................................................................................... 30 Advantages of Redundant Streaming .................................................................................................................................... 33 The Audio Cloud - “Ultimate Resilience” .................................................................................................................................. 34 Redundant Streaming .................................................................................................................................................................. 35 Distributed Intelligence ............................................................................................................................................................... 35 Packet Forwarding ......................................................................................................................................................................... 35 Multicast / Multiple Unicast Relocation ................................................................................................................................. 36 CONTENTS 6. Advanced IP Concepts a. The IP Layer & Protocols ................................................................................................................................38 The OSI Reference Model ..........................................................................................................................38 The Four Layers of the TCP/IP Model ......................................................................................................38 The Link Layer (OSI layer 1 & 2) .................................................................................................................38 The Internet Layer .........................................................................................................................................38 The Transport Layer ......................................................................................................................................39 Encapsulation of Protocols and Services ..............................................................................................40 b. MAC & IP Addresses ........................................................................................................................................40