The Shortcut Guide to Optimized WAN Application Deliveryby Ed Tittel
The Shortcut Guide to Optimized WAN Application Delivery offers insight into the whys and wherefores, as well as the nuts and bolts involved in optimizing WAN applications to improve the end user experience. Along the way, readers will learn about the features and shortcomings of TCP/IP that help to make WAN optimization necessary. By the time readers finish this eBook, they will be comfortable with the key issues involved in optimizing WAN applications, as well as the tools and techniques used to improve WAN application experience and enhance user perceptions.
"IT professionals seeking to understand how WAN optimization can help to improve application response time and performance will find The Shortcut Guide to Optimized WAN Application Delivery to be an invaluable resource," explains author Ed Tittel. "They will learn how WAN applications are optimized, what kinds of optimization tools and techniques deliver the best results, and how to use WAN optimization to improve the end user experience."
Chapter 1: Networking Issues and Complexity Increase as Technology Improves and Speeds Up
Today's business environments have scaled to new heights and reached new plateaus. An increasingly globalized economy continues to transform modern enterprises to adopt more adaptive networking and business service management (BSM) models. At the same time, an increasingly mobile workforce demands remote connectivity for its people, processes, and resources. As organizations and employees become ever more distributed throughout branch offices and off-site locations, boosting productivity grows increasingly important in all kinds of interesting—and unobvious—ways. All users require efficient, secure, and unimpeded access to critical business applications wherever and whenever they create static or temporary workspaces: company headquarters, branch offices, and even off-site client locations.
Several distinct and high-impact business requirements and technology trends compel the need for organizations to further improve performance, while increasing security and managing risk in their business applications. To remain competitive within increasingly challenging markets, IT must streamline the business by ensuring superior application responsiveness and delivering an agile infrastructure without undue (or any) increases to operational costs or headcount. Then too, a burgeoning set of state and federal regulatory requirements and an increase in underlying threats and vulnerabilities continues to raise the bar when it comes to managing and accepting risk. At the same time, the intersection of consolidation, outsourcing, and mobility pushes applications and end users ever further apart. This creates extraordinary pressures on both network technologies and network traffic patterns.
Centralized applications and widely distributed users can impose huge performance penalties on modern business environments, where remotely connected users suffer most from network latency and bandwidth constraints. Although ongoing trends toward consolidating or outsourcing critical applications and servers to fewer locations may simplify administration tasks, consolidation and virtualization can also pose performance problems to a distributed user base. Such problems are often particularly, if not spectacularly, evident whenever business-critical applications and resources are scattered among a variety of remote global locations and across numerous servers. When combating these difficulties, many organizations turn to solutions to accelerate and secure the delivery of business applications for all users across a distributed enterprise—including those near Internet gateways, located within branch offices or data centers, and even at individual end-points.
Chapter 2: Managing Scale and Scope in a Distributed WAN Environment
At the very core of every network infrastructure is the routing process. Network cabling and media, in all its various forms, creates the veins and arteries for the network, where routing is a dynamic internal process through which data travels around a system composed of intermediary devices and connection endpoints. Routing manages the communications path selection process in computer and telecommunications networksâ€”and is a component function in all such networksâ€”and determines when and where to deliver data-bearing traffic. Routing involves the direct forwarding of data packets in packet-switched networks to designated endpoint addresses through intermediary devices known as routers, bridges, switches, firewalls, and gateways.
The science of routing is the process of identifying connective pathways along which to deliver data between subnets or external network sources, using a variety of logical and algorithmic techniques. It is the directional flow of datagram or packet traffic from source to destination according to some defined passageway that is typically specified through administratively managed memory-resident routing tables. A router selects the correct interface from its available routing table and determines the next hop along which to forward a packet. Similar network address structures (closely related numeric values) imply proximity within a network, even for WAN-spanning connections. The process of accessing the Internet through a WAN connection is depicted in Figure 2.1.
Chapter 3: WAN Optimization Tools and Techniques
Any good tool requires its builders to cycle from circumstances (necessity), to conceptualization and creation (invention), before they can explore those developmental processes that kick-start innovation and growth. Software and hardware are no different in this regard. Even when tools are short-lived and quickly replaced or retired, they often serve as a basis or foundation for future developments. WAN optimization tools borrow tips, tricks, and techniques from many other disciplines that are not unique to WAN solutions. Even so, WAN optimization solutions usually combine multiple approaches and algorithms, some disjoint and independent, others interrelated and interdependent, into a single framework designed to enhance WAN performance.
Outmoded legacy applications and protocols also guide us to better designs, in part by serving as base references for inspiration and new implementations. Likewise, tried and true optimization techniques from areas as diverse as operating systems and databases also play a role in inspiring and informing WAN optimization tools and technologies. Although WAN optimization draws its ideas and techniques from many different computing disciplines, it uses them in its own interesting and specific ways to reduce the amount of data that must traverse WAN links, the frequency at which such traversals must occur, and the kinds of communications and protocols used to communicate across them.
If you perceive earlier network protocols as having grandfathered a newer generation of performance-enhancing network processes, protocols, and procedures you already have a good grasp on where WAN optimization is headed. You might also notice that steady, incremental improvements have also helped to optimize routing behaviors in an ever-increasing number of ways. This lets all of us understand that the motivation behind improving network performance remains the same, even when the modus operandi changes. From the broadest possible perspective, then, WAN optimization is just one class of tools available to designers and managers to help them make the most of their networks.
Chapter 4: Challenges and Best Practices for WAN Optimization
WAN acceleration is a key enabler of strategic IT initiatives and enterprise goals, including branch office networking, central storage repositories, and business continuity planning. WAN connections and delivery may be established using dedicated leased lines or cloud services that are owned and operated by providers and shared by multiple subscribers. Furthermore, the diversity among protocols, platforms, and performance rates adds layers of complexity to traffic optimization for network engineers and infrastructure implementers.
Ultimately, the real meat of the WAN optimization discussion hinges on application delivery. This topic is probably best understood as a form of optimization that incorporates a deep and detailed understanding of application traffic patterns, network messages, and overall behavior. This approach provides a foundation for optimization techniques that includes smart use of proxies, protocol optimization, application behavior optimization, and more. It makes effective use of the techniques and technologies described in the previous chapter, particularly compression, various levels of caching, and streamlining of network traffic behavior to make the most of the WAN bandwidth available for application use. Above all, with a serious focus on delivering the best overall end-use experience, optimization and its metrics can improve productivity and usability. In turn, this depends on creating and maintaining an optimal application infrastructure, designed to improve response time and to deliver a positive application access experience.