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WAN performance: Application delivery, optimization and the end user

A distributed enterprise, real-time applications like video, server virtualization and cloud computing all factor in to poor application performance.

An application delivery optimization strategy is most effective in ensuring good application performance. Learn...

how to empower your enterprise wide area network (WAN) to respond quickly and securely to user requirements. Use the advice below to overcome slow app performance.

 Which IT trends are challenging WAN application delivery?

Three trends are changing the way organizations must think about application traffic on the network: the increasingly distributed enterprise, the rise of real-time applications (video in particular), and the rise in server virtualization and cloud computing. As a result of these trends, enterprise application traffic -- both end-user-facing and generated as part of applications' internal workings -- is increasingly flowing across the WAN and the Internet. In the face of these changes, the network must become more intelligent and more focused on application delivery optimization.

Two things characterize the first trend, enterprise distribution. First, users are increasingly located in branch offices. Between 2005 and 2009, the number of branch offices grew an average of 9.2% each year. Although the number of branch offices dropped slightly (3.1 %) from 2009 to 2010, all signs indicate that 2010 will be a rebound year, with branch offices growing a whopping 17%. We see steady increases in telecommuting as well. Second, branch and teleworkers get services increasingly from a shrinking set of central data centers as IT centralizes services out of branches and consolidates data centers into fewer, larger facilities. Together, these trends mean that about 90% of users get their applications over the WAN.

The second trend -- the rise of real-time applications, particularly video -- can be characterized in many ways. In 2009, 79% of enterprises said using video reduced travel costs, and 43% of organizations had a policy in place to encourage video use. Nemertes Research anticipates that these trends will continue through 2010 and beyond as people become more comfortable using video conferencing and systems and services continue to be cost-effective.

Finally, there's the trend toward server virtualization, and ultimately cloud computing. More than 90% of organizations are at least test-driving server virtualization, which decouples applications from physical computing and storage infrastructure. The next logical step is to explore locating these decoupled application workloads in the cloud. Sixty percent of organizations say they're using some form of software-as-a-service (SaaS), and although adoption of infrastructure-as-a-service (IaaS) cloud computing lags far behind (just 20% say they're even considering IaaS for 2010), there is clear long-term interest.

 Why WAN application delivery optimization solves poor performance

Organizations are increasingly focusing on ways to optimize application delivery over the network -- what Nemertes refers to, logically enough, as "application delivery optimization." Enterprises look to four key techniques for improving WAN performance: compression, caching, protocol acceleration, and prioritization (or traffic shaping). Vendors including  Blue Coat Systems, Cisco, Juniper, and Riverbed put different subsets of these functions in WAN optimization appliances or integrate them with security or switching/routing functionality.

Service providers have begun offering optimization as a service. This comes in two basic flavors:

  • Carrier/cloud optimization
  • Overlay network optimization

AT&T, BT, Orange Business Services, TaTa Communications, and Verizon Business, among others, offer carrier/cloud optimization, usually via managed customer premise equipment, sometimes completely in the cloud. Akamai, Internap and LimeLight, among others, provide overlay optimization, using a dedicated network to speed the delivery of specific kinds of content. These services are more popular with enterprise users -- 43% would prefer optimization services to in-house deployments, other things being equal.

 How WAN managers can succeed in deploying application delivery optimization

One major application delivery optimization challenge for IT is to recognize and manage user expectations. That's no easy task: End-user expectation of application performance is rapidly becoming time- and location-independent. No matter where they are, how they are connecting, or what time of day they are working, users expect good, uniform performance.

Another crucial challenge is to understand application characteristics. Depending on how they are architected, some applications (such as email) can be relatively insensitive to network performance. They aren't sensitive to latency and packet loss, they are asynchronous, and end-user experience is largely independent of network characteristics. Others applications -- particularly video, remote desktops, and real-time interactive applications -- are more persnickety. IT professionals need to understand which applications are sensitive and architect an application delivery optimization strategy that clearly prioritizes them.

They key? Think in terms of service delivery. Once the IT folks understand user expectations and application characteristics, they should craft service-level agreements (SLAs), which are critical to application delivery. If necessary, SLAs should be linked to chargeback -- so a business unit that requires premium delivery of, say, high-definition video conferencing pays the extra costs required to guarantee that delivery.

Security and reliability can't be an afterthought in this calculation. Enterprises need to develop an application delivery optimization strategy in conjunction with security and disaster recovery strategies.

The bottom line? Effective application delivery optimization is about empowering the network to respond appropriately, and securely, to user requirements.

Johna Til Johnson

About the author:
Johna Till Johnson is president and senior founding partner of Nemertes Research, where she sets research direction and works with strategic clients. She has decades of experience in IT structure, processes, and organizations and has worked closely with senior IT executives at leading organizations across a broad range of industries. A highly regarded expert, Johnson regularly speaks at trade shows, conferences and seminars and writes an insightful weekly column in Network World .


This was last published in May 2010

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