Network Simulation for Professional Audio Networks
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Network Simulation for Professional Audio Networks Submitted in fulfilment of the requirements of the degree Doctor of Philosophy of Rhodes University Fred Otten June 2014 Abstract Audio Engineers are required to design and deploy large multi-channel sound systems which meet a set of requirements and use networking technologies such as Firewire and Ethernet AVB. Band- width utilisation and parameter groupings are among the factors which need to be considered in these designs. An implementation of an extensible, generic simulation framework would allow audio en- gineers to easily compare protocols and networking technologies and get near real time responses with regards to bandwidth utilisation. Our hypothesis is that an application-level capability can be developed which uses a network simulation framework to enable this process and enhances the audio engineer’s experience of designing and configuring a network. This thesis presents a new, extensible simulation framework which can be utilised to simulate professional audio networks. This framework is utilised to develop an application - AudioNetSim - based on the requirements of an audio engineer. The thesis describes the AudioNetSim models and implementations for Ethernet AVB, Firewire and the AES- 64 control protocol. AudioNetSim enables bandwidth usage determination for any network configuration and connection scenario and is used to compare Firewire and Ethernet AVB bandwidth utilisation. It also applies graph theory to the circular join problem and provides a solution to detect circular joins. Acknowledgements Firstly I would like to thank God “For from him and through him and to him are ALL things” (Ro- mans 11:36 [NIV], Emphasis added). My life is a testimony of his mercy and grace. He has given me my abilities and deserves all the glory. I would like to thank my beautiful wife - Nicki - for her support and encouragement throughout this process. I would also like to thank my family and friends for their support on this journey. I specially want to thank my supervisor - Prof. Richard Foss - for all his advice and guidance over the years as I have completed this work. His knowledge and expertise has taught me so much and I really appreciate all the time and effort he has put in to help shape this work. I would also like to thank all the people in the Computer Science Department - particularly my peers Nyasha Chigwamba, Philip Foulkes and Osedum Igumbor. Thanks for reading through sections of my thesis and for the many great times we shared working together in the lab. I would finally like to thank Telkom SA for allowing me to complete these studies and the Andrew Melon Foundation and DAAD for their generous financial support. UMAN is acknowledged for the provision of hardware devices and the use of the UNOS Vision software. The sponsors of the Center of Excellence at Rhodes University (Telkom SA, Business Connexion, Comverse, Verso Technologies, THRIP, Stortech, Tellabs, Mars Technologies, Amatole Telecommunication Services, Bright Ideas 39, Open Voice and the National Research Foundation) are also acknowledged. Contents 1 Introduction 1 1.1 Introduction . 1 1.2 Professional Audio Networks . 1 1.3 Problem Statement . 3 1.4 Network Simulation . 4 1.5 Research Questions . 4 1.6 Thesis Layout . 4 1.6.1 Chapter 2 - Introduction to Firewire and AVB Networks . 4 1.6.2 Chapter 3 - Network Simulation . 5 1.6.3 Chapter 4 - Network Design Applications . 5 1.6.4 Chapter 5 - Overview of Sound System Control and AES64 . 5 1.6.5 Chapter 6 - Network Simulator Design . 5 1.6.6 Chapter 7 - Modelling and Analysing Joins . 5 1.6.7 Chapter 8 - Bandwidth Calculation for Firewire and AVB Networks . 5 1.6.8 Chapter 9 - Comparison of Firewire and AVB Networks . 6 2 Introduction to Firewire and AVB Networks 7 2.1 Introduction . 7 2.2 Firewire Networks . 7 2.2.1 The nature of the Firewire bus . 8 2.2.1.1 CSR Architecture . 8 2.2.1.2 Firewire Bridges and Routers . 10 2.2.1.3 Firewire Communications Model . 11 2.2.1.4 Operation of a Firewire Network . 12 i CONTENTS ii 2.2.1.5 Physical Layer . 13 2.2.2 Transmission Modes . 13 2.2.2.1 Isochronous Transmission . 13 2.2.2.2 Asynchronous Transmission . 16 2.2.3 Arbitration . 17 2.2.3.1 Legacy Arbitration . 17 2.2.3.2 1394a Enhancements . 18 2.2.3.3 BOSS Arbitration . 19 2.2.4 Configuration . 22 2.2.5 Timing and synchronisation . 23 2.2.6 IP over 1394 . 24 2.3 Ethernet AVB Networks . 24 2.3.1 Ethernet AVB . 25 2.3.2 Queues, Priorities and Packet Types . 27 2.3.2.1 Traffic Classes . 27 2.3.2.2 Selection Algorithms . 28 2.3.2.3 Queue Types . 29 2.3.3 Timing and synchronisation . 29 2.3.4 The Multiple Reservation Protocol (MRP) and its applications . 30 2.3.4.1 MRP . 30 2.3.4.2 MVRP . 33 2.3.4.3 MSRP . 33 2.3.5 Transmission of Streaming Data . 37 2.4 Conclusion . 38 3 Network Simulation 39 3.1 Introduction . 39 3.2 Network Simulation . 39 3.2.1 Definitions and Concepts . 40 3.2.2 Existing Network Simulation . 41 3.2.3 Network Simulation Requirements . 42 3.2.4 Tension between Abstraction and Accuracy . 42 CONTENTS iii 3.2.5 Concluding Remarks . 43 3.3 A Representational approach to modelling Firewire . 44 3.3.1 NS-2 . 44 3.3.2 NS-2 Firewire implementation . 45 3.3.2.1 Tcl code . 46 3.3.2.2 C++ code . 49 3.3.3 Evaluation of NS-2 . 55 3.3.3.1 The network animator . 56 3.3.3.2 Tracefile output . 56 3.3.3.3 Setting up a network scenario . 58 3.3.3.4 Outputting required information . 59 3.3.4 Concluding Remarks . 59 3.4 Conclusion . 59 4 Network Design Applications 61 4.1 CobraCAD . 61 4.2 mLAN Installation Designer . 64 4.3 HiQNet London Architect . 66 4.4 Harman System Architect . 68 4.5 Comparison of Existing Configuration and Design Programs . 70 4.6 Usability Requirements for Network Simulator Application . 72 4.7 Conclusion . 73 5 Sound System Control Protocols 74 5.1 Introduction . 74 5.2 Comparison of Protocols . 75 5.2.1 Device Model and Parameter Addressing . 75 5.2.2 Transport independence . 77 5.2.3 Monitoring and Control . 77 5.2.4 Device Discovery . 77 5.2.5 Standardisation . 78 5.2.6 Graphical Control Applications . 78 CONTENTS iv 5.2.7 Connection Management . 78 5.2.8 Grouping . 78 5.2.9 Concluding Remarks . 78 5.3 AES64 . 79 5.3.1 Protocol Overview . 79 5.3.1.1 7 level structure . 80 5.3.1.2 Commands and Responses . 81 5.3.1.3 Wildcarding Mechanism . 81 5.3.1.4 The Universal Snap Group (USG) Mechanism . 83 5.3.1.5 Desk Items . 83 5.3.2 Connection Management . 83 5.3.2.1 IEEE 1394 . 83 5.3.2.2 Ethernet AVB . 84 5.3.3 Parameter Control . 85 5.3.3.1 Control Application - UNOS Vision . 86 5.3.4 Parameter Monitoring . 88 5.3.5 Parameter Grouping . ..