Advanced Content Delivery, Streaming, and Cloud Services pdf pdf

  ADVANCED CONTENT

DELIVERY, STREAMING,

AND CLOUD SERVICES

  ADVANCED CONTENT

DELIVERY, STREAMING,

AND CLOUD SERVICES

  Edited by Mukaddim Pathan

  Telstra Corporation Ltd., Australia

  Ramesh K. Sitaraman

  University of Massachusetts, Amherst and Akamai Technologies, USA

  Dom Robinson

  id3as-company Ltd., UK Cover Image: iStockphoto © nadla Cover Design: Wiley Copyright © 2014 by John Wiley & Sons, Inc. All rights reserved. Published by John Wiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada.

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  Library of Congress Cataloging-in-Publication Data: Advanced content delivery, streaming, and cloud services / editors, Mukaddim Pathan, Ramesh K.

  Sitaraman, Dom Robinson. pages cm Includes index.

  ISBN 978-1-118-57521-5 (hardback)

1. Cloud computing. 2. Computer networks. I. Pathan, Mukaddim. II. Sitaraman, Ramesh Kumar, 1964- III.

Robinson, Dom.

  QA76.585.A377 2014 _′ 004.67 82–dc23 2014005235 Printed in the United States of America.

  

To my wife Ziyuan for her inspiration, love, and support. This book would not

have been completed, if she did not single-handedly take care of everything,

while I was too busy in writing and compilation!—Mukaddim

To my wife Vidya for her love and support. And to our lovely children Anu and

  

Siddu for reminding me that despite our best efforts the Internet still isn’t fast

enough for them!—Ramesh

To my wife Mariana and our wonderful kids Sofia and Zac—I am sure you will

enjoy this book as a bedtime reading. And to my parents (that funny “computer

thing” you bought me as a kid came in handy!)—Dom

  CONTENTS

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

   Dom Robinson

  

  

  

  

   Mukaddim Pathan

  

  

  

  

  

  

  

  

  

  

  

  

  

   CONTENTS

  

  

  

  

  

  

  

  

  

   Hussein A. Alzoubi, Michael Rabinovich, Seungjoon Lee, Kobus Van Der Merwe, and Oliver Spatscheck

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

   Dom Robinson

  

  

  

  

  

  

  

  

  

  4 EFFICIENCY OF CACHING AND CONTENT DELIVERY IN

   Gerhard Haßlinger

  

  

  

  

  

  

  

  

5 ANYCAST REQUEST ROUTING FOR CONTENT DELIVERY

  CONTENTS

  

  

  

  

  

  

  

  

  

  Timothy Siglin

  

  

  

  

   Tiago Cruz, Paulo Sim̃oes, and Edmundo Monteiro

  

  

  

  

   Ram Lakshmi Narayanan, Yinghua Ye, Anuj Kaul, and Mili Shah

  

  

  

  

  

  

  

  

PART II CDN PERFORMANCE MANAGEMENT AND OPTIMIZATION 159

  CONTENTS

   CONTENTS

  

  

  

  

  

  

  

  

  

  

   Marat Zhanikeev

  

  

  

  

  

  

  

   Benjamin Molina, Jaime Calvo, Carlos E. Palau, and Manuel Esteve

  

  

  

  

  

  

  

  

  

   Tolga Bekta¸s and Ozgur Ercetin

  

  

  12 BEYOND CDN: CONTENT PROCESSING AT THE EDGE OF THE

  

   Phil Davies and Mukaddim Pathan

  

  

  

  

  

  

  

  

   Eugenio Cesario, Carlo Mastroianni, and Domenico Talia

  14 MINING DISTRIBUTED DATA STREAMS ON CONTENT DELIVERY

  

  

  

   Salekul Islam and Jean-Charles Gr ́egoire

  

  

  

  

   Norihiko Yoshida

  

  

  

  

  

  

  

  

  

  CONTENTS

   Vivek S. Pai

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

   Ramesh K. Sitaraman, Mangesh Kasbekar, Woody Lichtenstein, and Manish Jain

  PART III CASE STUDIES AND NEXT

  

  

  

  

  

   Michael Talyansky, Alexei Tumarkin, Hunter Xu, and Ken Zhang

  CONTENTS

  

  

  

  

  

  

  

  

  

  

  

   Piotr Srebrny, Dag H.L. Sørbø, Thomas Plagemann, Vera Goebel, and Andreas Mauthe

  20 CacheCast: A SINGLE-SOURCE MULTIPLE-DESTINATION

  

  

  

  

  

  

  

  

  

  

  

  

   Mirosław Czyrnek, J ¸edrzej Jajor, Jerzy Jamro˙zy, Ewa Ku´smierek, Cezary Mazurek, Maciej Stroi´nski, and Jan W ¸eglarz

  19 PlatonTV: A SCIENTIFIC HIGH DEFINITION CONTENT DELIVERY

  

  

  

  18.3 Directions for Future CDN Research and Trends in

  

  CONTENTS

21 CONTENT REPLICATION AND DELIVERY IN

  

  

  

  

  

  

  

  

  

  

  

   Irene Kilanioti, Chryssis Georgiou, and George Pallis

  23 ON THE IMPACT OF ONLINE SOCIAL NETWORKS IN CONTENT

  

  

  

  

  Vasilis Sourlas, Paris Flegkas, Dimitrios Katsaros, and Leandros Tassiulas

  

  

  

  

  

  

Giancarlo Fortino, Carlos T. Calafate, Juan C. Cano, and Pietro Manzoni

  

  

  

  

  

  

  

  PREFACE

  The ever-evolving nature of the Internet brings new challenges in managing and delivering content to end-users. Content Delivery Networks (CDNs) improve Web access and streaming performance, in terms of response time and system through- put, while delivering content to Internet end-users through multiple, geographically distributed edge servers. The CDN industry, that is, content delivery, consumption, and monetization, has been undergoing rapid changes. The multidimensional surge in content delivery from end-users has led to an explosion of new content, formats, and an exponential increase in the size and complexity of the digital content supply chain. These changes have been accelerated by economic downturn in that the content providers are under increasing pressure to reduce costs while increasing revenue.

  The main value proposition for CDN services has shifted over time. Initially, the focus was on improving end-user-perceived experience by decreasing response time, especially when the customer website experiences unexpected traffic surges. Nowadays, CDN services are treated by content providers as a way to use a shared infrastructure to handle their peak capacity requirements, thus allowing reduced investment cost in their own hosting infrastructure. Moreover, recent trends in CDNs indicate a large paradigm shift toward a utility computing model, which allows customers to exploit advanced content delivery services, hosted on commodity hardware, without having to build a dedicated infrastructure.

  From a market perspective, historically buyers based the bulk of demand and spend- ing on “core” CDN products that facilitate the delivery of Web-based content services. Over the last few years, offering from video streaming and value-added services (VASs) peaked as the most demandable CDN products. They formed the basis of most of the present-day CDNs’ offering, while strong demand for the basic CDN services still con- tinues. Market research shows that on average, buyers reported 43% of total CDN spend- ing on core products, such as caching and content delivery, while 57% spending on VAS-based products.

  While satisfying the market demands, CDN providers are more and more focusing on higher margin, VAS offering in order to gain (or stabilize) overall profit margins. These VASs include mobile data acceleration, content protection, content management, application acceleration, mobile data delivery, and cloud-based storage. While these products currently have a reasonable market penetration, they represent even more sub- stantial near-term growth opportunities.

  PREFACE

  In addition to the emergence of innovative CDN models, such as managed CDNs, licensed CDNs, and federated CDNs, Telco/operator CDNs are evolving into major market share holders. Telcos/operators around the world have started building CDN platform, technology, and support to aid content consumption, delivery, and rich media experience by end-users. The geographic expansion of Web-based content continues to grow and drive global CDN business requirements. Many CDN players have started with a regional focus and then expanded to offer services in new regions. It is expected that these trends in the CDN industry will continue, as the definition and scope of a CDN gets broader.

  1.1 OVERVIEW AND SCOPE OF THE BOOK

  The book entitled Advanced Content Delivery, Streaming, and Cloud Services presents fundamental and trendy CDN technologies, with a comprehensive coverage of evolu- tion, current landscape, and future roadmap. The book builds on academic and industrial research and developments, and case studies that are being carried out at different orga- nizations around the world. In addition, the book identifies potential research directions and technologies that will drive future innovations. This book is aimed at a large audi- ence including systems architects, practitioners, product developers, and researchers. It can be used as a reference/textbook for graduate students and a roadmap for academi- cians, who are starting to research in the field of content delivery. We expect the readers to have at least the basic knowledge about Web technologies and the Internet. In partic- ular, readers should be knowledgeable about Web caching, replication, Internet-based services and applications, and basic networking.

  Upon reading this, book readers will perceive the following benefits:

  1. Learn the state of the art in research and development on content management, delivery, and streaming technologies.

  2. Obtain a future roadmap by learning open research issues.

  3. Gather the background knowledge to tackle key problems, whose solutions will enhance the evolution of next-generation content networks.

  4. Use the book as a valuable reference and/or textbook.

  1.2 ORGANIZATION OF THE BOOK

  This book is organized into three parts, namely, Part I: CDN and Media Streaming Basics; Part II: CDN Performance Management and Optimization; and Part III: Case Studies and Next-Generation CDNs. Specifically, the topics of the book are the following:

• CDN—Infrastructure, architecture, and technology for web content delivery,

PREFACE

• Adaptive Bitrate Streaming (ABR). Techniques for multimedia streaming over computer networks using the HTTP protocol.
• Cloud-Based Content Delivery. Integration of cloud computing with traditional CDN model for content and Web application delivery.
• Wide Area Network (WAN) Optimization. Optimization algorithms to increase data transfer efficiency in an end-to-end delivery path across WANs.
• Mobile Acceleration Service. Optimizing content and video streams to mobile devices to meet dynamic and personalized content needs of mobile users.
• Transparent Caching. Carriers network caching technology to control over what content to cache, when to cache, and how fast to accelerate the content delivery.
• Request-Routing Techniques. Known and advanced algorithms for redirecting end-user requests, such as DNS-based routing, anycasting, and content-based routing.
• CDN Performance, Availability, and Reliability. SSL processing, network-based personal video recorder (PVR), and measurement techniques.
• Next-Generation CDNs. Overview of managed/licensed CDN, Telco/carrier CDNs, P2P CDN, and federated CDNs.
• CDN Case Studies. Overview of operational infrastructure and services from the major CDNs.
• CDN Business Intelligence. Coverage of the CDN market trends, ongoing plan- ning, and management.

  Part I of the book focuses on the basic ideas, techniques, and current practices related to content delivery and media streaming. Chapter 1 by Pathan presents an overview of CDNs, operational models, and use cases. It covers recent market and technology trends, as well as identifies a few research issues in the CDN domain. Robinson, in Chapters 2 and 3, provides a comprehensive description of the live media streaming ecosystem and demonstrates the practical configuration of live streaming using a few tools. In Chapter 4, Haßlinger identifies key properties of caching and content delivery in broadband access network, and describes how efficiency can be achieved by configuration and performance tuning. Alzoubi et al. in Chapter 5 present mechanisms and algorithms to effectively redi- rect end-user requests in a CDN platform. This chapter demonstrates the applicability of IP anycasting for request redirection. Basics of content delivery to cloud-based home ecosystem is covered in Chapter 6 by Cruz et al., highlighting key challenges, indus- try practices, and recent trends. In Chapter 7, Narayanan et al. describe the challenges in delivering video in mobile networks and present various adaptation techniques for mobile video streaming.

  Part II of the book provides a coverage of CDN performance measurement tech- niques, tools, reporting, and analytics. In Chapter 8, Siglin covers CDN analytics tools and explores a variety of analytic practices and their implications in practical context, including new methods for analyzing adaptive bitrate (ABR) streaming technology. Mathematical modeling to optimize CDN services, such as video on demand (VoD)

  PREFACE

  aware of fundamental optimization problems arising in content delivery and the ways of effectively solving these problems. Molina et al. in Chapter 10 present a basic analytical model to analyze the basic and advanced properties of a CDN. Zhanikeev in

  Chapter 11 describes a method for cloud-based multisource streaming and compares its performance over traditional methods. In Chapter 12, Islam and Grégoire discuss on the intersection of CDN and cloud computing by exposing a number of trade-offs on the deployment of multimedia processing functions inside the cloud and identify relevant performance factors. In Chapter 13, Yoshida describes the performance of a dynamic streaming CDN, comprising techniques for dynamic network reorganization, and load distribution and balancing to realize dynamicity, as well as techniques for stream seg- mentation and reconstruction, and QoS assurance. Cesario et al. in Chapter 14 present the analysis of mining streaming data in a CDN, improving efficiency and effectiveness of a CDN architecture. A hybrid multidomain architecture is described that solves the problem of computing frequent items and frequent itemsets from distributed data streams. In Chapter 15, Davies and Pathan cover the capacity planning process that is instrumental for the ongoing operation of a deployed CDN infrastructure. It includes a practical application and workflow of the CDN capacity planning process.

  Part III, the final part of the book, consists of a handful of representative case studies on present- and next-generation CDNs. In Chapter 16, Sitaraman et al. discuss differ- ent network overlays that are crucial for meeting the needs for Internet-based services. Architecture and techniques of representative overlays are discussed, along with their practical usage and implications. Chapter 17 by Pai provides coverage of a variety of next-generation CDNs and presents a case study of CoBlitz, a research CDN that became a commercial licensed CDN. In Chapter 18, Talyansky et al. describe the challenges of content delivery in China, by drawing on experience from ChinaCache, a carrier-neutral CDN. A brief coverage of content-aware network services offered by ChinaCache is provided, along with future trends of content delivery within China. Chapter 19, by Czyrnek et al., presents a case study of a high definition (HD) interactive TV platform, called PlatonTV. In addition to describing the PlatonTV architecture, different aspects of content delivery such as content ingest, content distribution, and management within the CDN are discussed. In Chapter 20, Srebrny et al. present CacheCast—a link layer caching system for single-source, multiple destination data transfers. In this case study, CacheCast architecture, operational methodology, and deployment details are presented. Sourlas et al. in Chapter 21 present a generic three-phase framework for content replica- tion in information centric networks (ICNs). Algorithms supporting efficient replication in ICN are discussed and performance benefits are demonstrated. Chapter 22 by Fortino et al. describes content delivery techniques in vehicular ad hoc networks (VANets). A content broadcasting methodology is presented, which improves content transfer time and delivery efficiency in the radio network. Finally, in Chapter 23, Kilanioti et al. discuss approaches to leverage information from online social networks (OSNs) for PREFACE

  rich media content delivery in CDNs. Future research directions in this area, along with a few commercial implications for CDNs, are also discussed.

  Mukaddim Pathan

  Telstra Corporation Ltd., Australia

  Ramesh K. Sitaraman

  University of Massachusetts, Amherst and Akamai Technologies, USA

  Dom Robinson

  id3as-company Ltd., UK

  ACKNOWLEDGMENTS

  This book came into light because of the direct and indirect involvement of many researchers, academics, and industry practitioners. We acknowledge and thank the contributing authors; research institutions; and companies whose papers, reports, articles, notes, websites, and study materials have been referred to in this book. We are thankful to Professor Albert Zomaya, editor of the Wiley Series on Parallel and Distributed Computing, for his support in accepting the book proposal and guiding us through Wiley’s publication process. We express our gratitude to Simone Taylor, Director, Editorial Development of John Wiley & Sons, Inc., and Wiley’s publication staff, for handling the book project and ensuring a timely publication.

  All chapters were peer reviewed, and authors have updated their chapters addressing the review comments. Prior technical sources are acknowledged citing them at appro- priate places in the book. In case of any errors, we would like to receive feedback so that it could be taken into consideration in the next edition.

  We hope that this book will serve as a valuable text for students especially at gradu- ate level and a reference for researchers and practitioners working in the content delivery domain.

  Mukaddim, Ramesh, and Dom

  CONTRIBUTORS Hussein A. Alzoubi Case Western Reserve University, Cleveland, OH, USA Tolga Bekta¸s University of Southampton, Highfield, Southampton, UK Carlos T. Calafate Universitat Politècnica de València, Valencia, Spain

Jaime Calvo Universidad de Salamanca, Escuela Politecnica Superior de Zamora,

  Zamora, Spain

  Juan C. Cano Universitat Politècnica de València, Valencia, Spain Eugenio Cesario ICAR-CNR, Rende (CS), Italy

Tiago Cruz Faculdade de Ciências e Tecnologia da, Universidade de Coimbra,

  Coimbra, Portugal

  

Mirosław Czyrnek Poznan Supercomputing and Networking Center, Pozna´n, Poland

Phil Davie Telstra Corporation Limited, Melbourne, Victoria, Australia Ozgur Ercetin Sabanc University, ˙Istanbul, Turkey Manuel Esteve Universitat Politecnica de Valencia, Valencia, Spain Paris Flegkas University of Thessaly, Oktovriou, Volos, Greece Giancarlo Fortino University of Calabria, Rende (CS), Italy

Chryssis Georgiou Department of Computer Science, University of Cyprus, Nicosia,

  Cyprus

  Vera Goebel University of Oslo, Oslo, Norway Jean-Charles Grégoire INRS-EMT, Montréal, QC, Canada Gerhard Haßlinger Deutsche Telekom Technik, Darmstadt, Germany Salekul Islam United International University, Dhaka, Bangladesh Manish Jain Akamai Technologies, Inc., Cambridge, MA, USA J ¸edrzej Jajor Poznan Supercomputing and Networking Center, Pozna´n, Poland Jerzy Jamro ̇zy Poznan Supercomputing and Networking Center, Pozna´n, Poland Mangesh Kasbekar Akamai Technologies, Inc., Cambridge, MA, USA Dimitrios Katsaros University of Thessaly, Oktovriou, Volos, Greece Anuj Kaul Nokia Siemens Networks, Mountain View, CA, USA

Irene Kilanioti Department of Computer Science, University of Cyprus, Nicosia,

  CONTRIBUTORS Ewa Ku´smierek Poznan Supercomputing and Networking Center, Pozna´n, Poland Seungjoon Lee AT&T Labs—Research, Florham Park, NJ, USA Woody Lichtenstein Akamai Technologies, Inc., Cambridge, MA, USA Pietro Manzoni Universitat Politècnica de València, Valencia, Spain Carlo Mastroianni ICAR-CNR, Rende (CS), Italy Andreas Mauthe InfoLab 21, Lancaster University, Lancaster, UK

Cezary Mazurek Poznan Supercomputing and Networking Center, Pozna´n, Poland

Benjamin Molina Universitat Politecnica de Valencia, Valencia, Spain

Edmundo Monteiro Faculdade de Ciências e Tecnologia da, Universidade de Coimbra,

  Coimbra, Portugal

  Ram Lakshmi Narayanan Nokia Siemens Networks, Mountain View, CA, USA Vivek S. Pai Princeton University, Princeton, NJ, USA Carlos E. Palau Universitat Politecnica de Valencia, Valencia, Spain

George Pallis Department of Computer Science, University of Cyprus, Nicosia, Cyprus

Mukaddim Pathan Telstra Corporation Ltd., Melbourne, Victoria, Australia Thomas Plagemann University of Oslo, Oslo, Norway Michael Rabinovich Case Western Reserve University, Cleveland, OH, USA Dom Robinson id3as-company Ltd., Rottingdean, Brighton, Sussex, UK Mili Shah Nokia Siemens Networks, Mountain View, CA, USA Timothy Siglin Braintrust Digital, Inc., Harriman, TN, USA

Paulo Simões Faculdade de Ciências e Tecnologia da, Universidade de Coimbra,

  Coimbra, Portugal

  

Ramesh K. Sitaraman University of Massachusetts, Amherst, and Akamai Technolo-

  gies, MA, USA

  Dag H.L. Sørbø University of Oslo, Oslo, Norway Vasilis Sourlas University of Thessaly, Oktovriou, Volos, Greece Oliver Spatscheck AT&T Labs—Research, Florham Park, NJ, USA Piotr Srebrny University of Oslo, Oslo, Norway Maciej Stroi ´nski Poznan Supercomputing and Networking Center, Pozna´n, Poland

Domenico Talia ICAR-CNR, Rende (CS), Italy; DIMES, University of Calabria,

  Rende (CS), Italy

  Michael Talyansky ChinaCache, Sunnyvale, CA, USA Leandros Tassiulas University of Thessaly, Oktovriou, Volos, Greece Alexei Tumarkin ChinaCache, Sunnyvale, CA, USA Kobus Van Der Merwe University of Utah, Salt Lake City, UT, USA Jan W ¸eglarz Poznan Supercomputing and Networking Center, Pozna´n, Poland Hunter Xu ChinaCache, Beijing, China

  CONTRIBUTORS Yinghua Ye Nokia Siemens Networks, Mountain View, CA, USA

Norihiko Yoshida Information Technology Center, Saitama University, Saitama, Japan

Ken Zhang ChinaCache, Beijing, China Marat Zhanikeev Kyushu Institute of Technology, Iizuka, Japan

  PART I CDN AND MEDIA

STREAMING BASICS

  1 CLOUD-BASED CONTENT

DELIVERY AND STREAMING

  Mukaddim Pathan Telstra Corporation Ltd., Melbourne, Victoria, Australia

1.1 INTRODUCTION

  Over the last decade, end-users have been increasingly using the Internet to access not only typical websites but also high definition (HD) video and rich media content. While accessing the Web, end-users expect high bandwidth, improved performance, and low latency for the delivered content. End-users’ requirements of high quality, consistent, dependable, responsive viewer experience can be characterized by faster loading Web pages, quick channel changes and downloads, fast-start video, and quality of experience (QoE) in mobile devices. Similarly, content providers require an efficient content deliv- ery mechanism to increase growth and scale, reliability and performance, and engage- ment and reach, while decreasing cost, risk, and network load.

  Content delivery networks (CDNs) [1–4] improve websites, streaming, and down- load performance of Internet content by end-users while reducing the cost to serve for content providers. A CDN is a collaborative collection of network elements spanning the Internet, where content is replicated over mirrored Web servers (i.e., point of pres- ence (PoP), edge or replica servers), located at the edge of the Internet service providers’ (ISPs’) networks to which end-users are connected. As shown in Figure 1.1, content is served into the CDN once, then content is delivered to end-users from the edge servers

  Advanced Content Delivery, Streaming, and Cloud Services , First Edition.

  Edited by Mukaddim Pathan, Ramesh K. Sitaraman, and Dom Robinson.

CLOUD-BASED CONTENT DELIVERY AND STREAMING

  Origin server Content acquisition ^{CDN PoP CDN PoP CDN PoP} Content delivery Connected devices

  ^{CDN PoP} at the edge ^{CDN PoP} Peering points

  Content acquires CDN

  ISP 2

  ISP 1

Figure 1.1 Abstract view of a CDN.

  rather than serving each individual request directly from the content provider’s origin server. Nowadays, CDNs are a prerequisite for delivering quality online experience for live, linear, and on-demand delivery of website and media content. They often leverage cloud (compute and storage) infrastructure and services to provide scalability, resiliency, availability, and performance.

  The reason why a CDN may be used varies depending on the particular enterprise—providing live streaming coverage of major events, distributing training videos to employees, providing fast and efficient software downloads to customers, or enhancing the performance of an e-commerce website. A few of these practical use cases are the following:

• Accelerated Web Performance. CDNs help to improve the delivery of website content (static and dynamic) so that websites perform better, load faster, and generate more revenue for content providers. CDNs not only cache static con- tent at the edge but also handle dynamic, transactional content from e-commerce providers, online auction sites, by accelerating the data transfer to provide an improved experience to end-users.
• Software Updates and Downloads. CDNs enhance the automatic or on-demand delivery of software or file downloads, including software patches. For example, consumers can fast download the latest release of operating system or word pro- cessing software releases online instead of ordering and purchasing in-store.
• Rich Media Content Streaming. CDNs help deliver rich media content, that is, interactive digital media such as audio and video files in different encoding for- mats (HyperText Transfer Protocol (HTTP) adaptive streaming with Microsoft Smooth, Adobe HDS, and Apple HLS [5,6]), to specialized streaming clients

CDN OVERVIEW

  streaming provides webcasts of corporate announcements, investor briefings, and online coverage of events such as the Olympics. On-demand streaming is per- formed with stored/archived content, based on end-user request to view it.

• IPTV Use Case. CDNs are used for Internet Pay TV (IPTV), such as catch-up TV service for recent programs of broadcasters, as well as online live video channels. This type of service features delivery of most media types, digital rights man- agement (DRM), multiple bitrate streaming, and distribution of video content to multiple regions. IPTV services over CDN apply both linear content delivery and on-demand content delivery.
• Managing and Delivering User-Generated Content. CDNs are often used to facil- itate the hosting and distribution of user-generated content. YouTube is the prime example where a CDN is used to deliver content uploaded by end-users. In addi- tion, CDNs open the way for new applications such as Enterprise TV (e.g., Enter- prise YouTube where corporate staff can upload and access video content) for interactions, training, and knowledge sharing.
• End-to-End Online Video. CDNs at its fullest use are often employed as the glue in integrating online video and content management platform to create an end-to-end delivery chain, offering a real differentiation through high quality user experience. Such end-to-end video delivery is composed of content ingest over Internet Protocol (IP) or satellite; content management and repurposing using specialized software, corporate storage, and hosting; content delivery using a CDN; and analytics-based management of IP-connected devices of end-users.

  This chapter sets the context for the book, by providing an overview of CDN tech- nologies, use cases, trends, and research directions in this domain. It presents how CDN is positioned with respect to the video ecosystem, followed by operational details of a CDN for several use cases. Coverage of recent technology trends in the CDN domain is provided to assist practitioners in this field; in addition, a few research issues are listed to demonstrate an R&D pathway to CDN researchers. While introductory concepts on many CDN terminologies, concepts, and technologies are covered in this chapter, read- ers should refer to later chapters in the book for detailed information and discussion on relevant CDN technologies.

1.2 CDN OVERVIEW

  In addition to the growing popularity of news, sports, and e-commerce website con- tent, accelerating demand for online HD video content, coupled with improvements in broadband technologies, and the increased availability of media-rich content are the key drivers behind using a CDN by content providers. At the most fundamental level, a CDN is about the efficient movement of digital content (video, software, audio, and files) across the Internet middle mile on a massive and ever-increasing scale. Let us con- sider a specific example (Figure 1.2) on how a CDN can be useful for large-scale video

CLOUD-BASED CONTENT DELIVERY AND STREAMING

  Local video streaming Remote video streaming _{m− z} viewers Embedded viewing window

  Aggregation Aggregation

  IP network core Aggregation

  

1−n

Media client Aggregation

  Media server Media server viewers _n−m Buffering...

  Ethernet network viewers Rationale behind CDNs: video streaming example.

  Figure 1.2

  to avoid contention. Moreover, the streaming server needs to be close to the end-user, characterized as local video streaming. When significant network infrastructure (i.e., Internet middle mile) is present between end-users and the originating media server, in the remote video streaming scenario, satisfactory performance may be obtained at a small scale. Nevertheless, as demand grows, end-user viewing experience gets increas- ingly worse (e.g., video buffering, jitter). Centralized media server suffers performance and reliability problems, and significant cost is incurred to deliver video files across large network distances. A CDN can be used to tackle such scenario where it helps to minimize the cost of video content delivery, ensures that network resources are utilized efficiently, and optimizes end-user experience.

  Without a CDN, bandwidth is overused as each request for the same content is retransmitted over and over. Moreover, a “brute force best effort” solution means that media content is not optimized (linear streaming vs video on demand (VoD)) for optimal edge delivery, as required for real-time video streaming. With a CDN, bandwidth usage of the content provider is optimized, as if a single end-user has requested unique con- tent only once. No additional investment is required by the content provider to increase bandwidth capacity, as media content is packaged for delivery by the CDN infrastructure.

  1.2.1 CDN Types

  The CDN market is highly dynamic, comprising a myriad of players, with different offer- ing and targeted market segments. Table 1.1 lists the different CDN types.

  1.2.2 Market and Product Segments

  A CDN is composed of content distribution and management, content routing,

CDN OVERVIEW

  T A B L E 1.1 Types of CDNs

  CDN Types Description

Pure-play CDN CDNs that provide over-the-top (OTT) delivery of video and audio

content without the ISPs being involved in the control and distribution of the content itself. Pure-play CDNs deliver content over ISPs’ network (e.g., Akamai) or own infrastructure (e.g., Limelight Networks, Level 3). Carrier/Telco CDN Broadband providers and Telcos, for example, Verizon, Telstra, AT&T, that provide content delivery as a means to reduce the demands on the network backbone and reduce infrastructure investment, using hardware and software from vendors, for example, Cisco, Juniper, or Alcatel-Lucent.

Managed CDN Pure-play CDNs can help carriers to build and manage the CDN

component of the carrier’s network with their professional services group, for example, Limelight Deploy. This approach leverages the expertise, infrastructure, and software of a pure-play CDN.

Licensed CDN Pure-play CDNs can also provide CDN software for integration,

testing, and deployment on the carrier’s infrastructure. Although integration assistance is initially available from the pure-play CDN provider, licensed CDN is managed by the network operator itself. For example, EdgeCast, Highwinds, and Akamai Aura provide licensed CDN product.

Federated CDN Multiple CDNs can interconnect their networks and compete more

directly against pure-play CDNs. It is interesting for a content provider willing to deliver its content to the aggregated audience of the federation [7,8]. Cisco and Highwinds are working toward federated CDNs.

  integration, self-service portal, professional services, and core networking. From a product perspective, a CDN provider can bundle content management, storage, and customer-onboarding (portal) services, in addition to the core CDN functionalities and value-added services (VAS). Figure 1.3 shows an example product portfolio of a CDN, showing the five constituents. Although earlier CDNs have been feature-rich in core functionalities, recent market trends indicate that traditional CDN services (e.g., caching, routing, delivery) are running the risk of being commoditized and sold mainly on price. Therefore, CDN providers are adding new services on top of their basic offering to generate revenue from running the business. There is a growing demand of

  VAS (e.g., website/application acceleration, Front-End Optimization (FEO), application security, rights protection, and analytics) and ancillary offering (e.g., origin storage, encoding/transcoding, content management, and ingest). It may also be required by a CDN to offer personalized service and custom solutions for individual enterprise customer needs. Details on the representative value-added and ancillary CDN services

CLOUD-BASED CONTENT DELIVERY AND STREAMING

  Content management services, Value-added services,

for example, publish, store, manage for example, FEO, App acceleration

CDN portal

Origin storage services for Core CDN services, for example,

encoding, lngest, playout caching, content delivery

Figure 1.3 Example product portfolio of a CDN.

  There are a number of driving forces in the CDN marketplace that influence the amount of revenue a CDN provider can make [9,10]. A representative list of these market drivers is provided in Table 1.2.

  From a market perspective, a CDN provider offers its services to the following market segments:

• E-commerce and Consumer Products/Retail. CDNs offer whole-site and dynamic content delivery services to website owners. A large portion of such websites is composed of applications and dynamic content, such as e-commerce/online retailers (eBay, Amazon), auction website (graysonline), and consumer products website (Walmart, JC Penny). These websites are heavily used during sales and special events (e.g., Thanksgiving, Christmas), requiring a CDN to tackle the heavy traffic demand for them.
• Media and Entertainment. CDNs offer progressive download, linear, VoD, and live streaming services to digital media companies such as content broadcasters (CNN, BBC), Internet-based publishing (Fairfax Media), and experimental dig- ital media (DXARTS, ACMI). These services are predominantly based on video content, with limited website static object caching. Users access the VoD or live streaming in mobile devices, set-top box, and online. CDNs help to deliver the video content at scale as well as tackle bursty traffic [11] for special events, such as the Cricket/Football World Cup and the Olympics.
• Hospitality, Travel, and Leisure. This market segment features websites and ser- vices used by end-users for accommodation booking, holiday booking, air ticket purchase, and so on. Similarly, in e-commerce websites, the websites Zuji, Expe- dia, and HotelClub have embedded applications and dynamic content, but differ in terms of back-end search and computation functionalities. This market seg- ment is aided by CDNs by taking care of the high traffic to websites, as well as application and database query execution at scale, during airfare/accommodation

CDN OVERVIEW

  T A B L E 1.2 CDN Market Drivers and Impacts

  Market Drivers Impact

Uptime/availability of The most crucial market driver to set up a CDN’s reputation

service as a reliable provider (and hereby to attract revenue-generating customers) is its service availability. Throughput performance CDN customers are increasingly looking at network throughput performance, as the key driver for choosing a

  CDN. Network performance: A CDN’s network performance, in terms of first byte

first byte delivery delivery, provides the very first impression of the service

provided by it and also gives the customer confidence on

its chosen CDN.

  Price Over the past years, CDN pricing has reached a commoditized level. CDNs are now focusing on value-added services (VAS) to generate revenue. There are six underlying cost models that appear frequently, namely, Gbps billing, GB transfer billing, GB storage billing, pay-as-you-go, monthly commit, and capped (percentile-based pricing).

Customer service The success of the relationship with the service provider is

defined by the moment the service fails and when it is too complex to initialize. When things go wrong, communication barriers only add to the frustration. Therefore, the customer service staff should have fluency to communicate in the language spoken by regional/global customer. Reporting/analytics For mission critical CDN services, real-time monitoring, “heartbeat” reporting, analytics, and live alerts are to be provided proactively, in order to cater for failure resolution. Customer portal/online An online account management system allows faster

account management customer onboarding and allows the customer to track

the service activation process, as well as ongoing account and/or service management.

Provider’s financial The CDN marketplace is very dynamic and has experienced

stability number of acquisition and/or mergers, as well as close

operations. A CDN provider has to demonstrate that it is making stable revenue from the market to gain

customers’ trust.

Sales process/ease of A customer always expects to be professionally guided

doing business through the sales process by the sales executive. The

sales process is a significant opportunity to impress and

secure the customer.

Range of products A CDN is often assessed by customers based on its product

portfolio and the VAS it provides. A set of innovative and trendy product feature set characterizes a CDN’s revenue potential.