Introduction

Within Internetworking, there are numerous career fields, such as network security, IP telephony, and Storage Area Networking (SAN). Content networking is growing so much that it has become a discipline of its own. In the past, most organizations have given the content networking responsibility to the IT operations or network security staff, but these days the field has become so large and complex that organizations often require dedicated content networking professionals to design and operate their content networks.

The purpose of this book is to introduce content networking as an individual field of study, and explain how numerous application and networking concepts are married to make the discipline a whole.

Goals and Methods

This book will first introduce you to some basic underlying networking technologies, which have been around for quite a while but that content networking uses in new and unique ways to accelerate your applications.

Once you understand the underlying technologies, this book uses the divide-and-conquer approach to address the single broad topic of content networking. By further isolating and examining content networking’s constituent technologies, you avoid the blurring and generalizing that tend to occur when discussing content networking. Covering each subtopic and its interdependencies in detail will give you valuable insight into the overall topic of content networking, without minimizing the importance of each subtechnology.

Who Should Read This Book?

This book is designed for any networking or application professional who requires an introduction to content networking. If you come to this book as an application professional, you will be able to obtain an introduction to the basic networking concepts from the first few chapters; this information may be superfluous to the network professional. On the other hand, networking professionals will be able to glean information about application concepts from the initial chapters to fully understand the content networking concepts discussed in this book.

Specifically, this book is an excellent resource for professionals who

• Design, implement, and maintain content networks

• Are preparing for the Cisco CCNP content networking exam

• Are responsible for technically justifying the purchase of content networking products to their management or purchasing departments

How This Book Is Organized

Although this book is designed to be read from cover-to-cover, it was also developed so that you can easily jump between its parts, chapters, and sections, enabling you to concentrate on only those topics that require your focused attention. As mentioned previously, both application- and network-centric professionals will learn a great deal about their IT counterpart’s native technologies. By allowing the reader to effectively concentrate on particular areas, this book benefits readers from diverse technical backgrounds.

Chapter 1 provides an introduction to content networking. Chapters 2 through 9 are framed as background chapters to content networking, giving a detailed examination of both the fundamentals of networks and applications. Chapters 10 through 14 are the core content networking chapters, with each Chapter providing a detailed treatment of a particular subtechnology of content networking. If you intend to read all the chapters, the order in the book is an excellent sequence to use.

The chapters of this book cover the following topics:

• Chapter 1, “Introducing Content Networking”— This Chapter offers general insight into the broad topic of content networking, including its purpose, goals, and subtechnologies.

• Chapter 2, “Exploring the Network Layers”— This Chapter examines Layers 1 through 4 of the Open Systems Interconnection (OSI) reference model, giving approximately equal coverage on each layer. To glue the layers together, this Chapter ends with an illustration of a sample application flow, showing how the layers interact with one another.

• Chapter 3, “Introducing Switching, Routing, and Address Translation”— This Chapter introduces how frames are switched by Layer 2 switches, how packets are routed and switched by Layer 3 routers, and how the transport segment’s IP addresses and port numbers are translated by Layer 4 content switches and firewalls.

• Chapter 4, “Exploring Security Technologies and Network Infrastructure Designs”— This Chapter covers major topics for securing your applications and network, such as packet filtering, application inspection, and encryption, and provides design backdrops for common networking infrastructures, including WANs, campuses, and Internet Content Delivery Networks (ICDN).

• Chapter 5, “IP Multicast Content Delivery”— Streaming media and content distribution can consume a great deal of network bandwidth. To deal with this issue, Chapter 5 provides a way to minimize potential flooding using IP multicast.

• Chapter 6, “Ensuring Content Delivery with Quality of Service”— This Chapter provides a way to minimize the impact of packet loss, delay, and jitter by enabling QoS features in your network.

• Chapter 7, “Presenting and Transforming Content”— This Chapter covers how to use Extensible Markup Language (XML)-based markup laguages for describing, presenting, and transforming content.

• Chapter 8, “Exploring the Application Layer”— This Chapter introduces the application layer and in particular the protocols that pertain to content networking concepts discussed throughout the book, including HTTP, Secure Sockets Layer (SSL), and FTP application layer protocols.

• Chapter 9, “Introducing Streaming Media”— This Chapter covers streaming media concepts, including how video on demand (VoD), live, and rebroadcast events are delivered using Real-Time Transport Protocol (RTP), Real-Time Streaming Protocol (RTSP), and Motion Picture Expert Group (MPEG) protocols. This Chapter also compares and contrasts Microsoft Windows, Apple QuickTime, and RealNetworks streaming technologies.

• Chapter 10, “Exploring Server Load Balancing”— This Chapter shows how to design redundancy and high availability into your server farms by configuring load distribution algorithms, health checks, session persistence, and Layer 5–7 load balancing on your content switches.

• Chapter 11, “Switching Secured Content”— This Chapter shows how to switch and offload encrypted content by importing, creating, and configuring certificates and keys in SSL termination devices, such as the Content Switching Module (CSM) with Secure Sockets Layer (SSL) daughter cards (CSM-S) and the Content Services Switch (CSS) SSL modules.

• Chapter 12, “Exploring Global Server Load Balancing”— This Chapter shows how to design redundancy and high availability across your sites, using the Domain Name System (DNS), Distributed Director, proximity-based load balancing, and global sticky databases.

• Chapter 13, “Delivering Cached and Streaming Media”— This Chapter examines how to configure your routers with Web Cache Control Protocol (WCCP) and content switches to switch requests to Content Engines (CE) for serving frequently requested objects. These frequently requested objects can include the following: HTTP and streaming media; standard caching services, such as web and reverse-proxy caching on your CEs using the Application and Content Networking System (ACNS); value-added services, such as content authentication and content preloading; and content freshness from CEs.

• Chapter 14, “Distributing and Routing Managed Content”— This Chapter explores how to configure ACNS for content distribution and routing serivces, by configuring channels of CEs, forwarding content to those channels, and using content request routing technologies, such as simplified hybrid routing and dynamic proxy auto-configuration, to route client’s requests for the distributed content.