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"c CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY c CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL MANAGEMENT c CHAPTER 3 DEPLOYING WAN OPTIMIZATION: IN-HOUSE OR OUTSOURCE? THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN Today’s businesses rely on wide area networks more than ever before, placing unprecedented demands on geographically dispersed networks that must function 24x7. This ebook explains the drivers leading to the WAN’s critical role and examines the strategies and technologies you can employ to manage traffic, increase performance and get costs under control, whether you do it yourself or use a service provider. CHAPTER 1 1 WAN investments that save money Many of today’s cost-saving IT projects are placing excessive pressure on the WAN. Learn how to overcome these challenges with WAN optimization technology. BY ROBIN LAYLAND a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT a CHAPTER 3 DEPLOYING WAN OPTIMIZATION p THE COMING YEAR looks to be a tough one, with network managers and their budgets under extreme pressure. IT must prove its worth more than ever before and come up with ways to save money and increase productivity. This can be approached in several ways. Strategies include consolidating servers from branch offices to the data center; using the latest version of desktop virtualization; increasing multimedia and video collaboration; moving applications to the Web with service-oriented architecture (SOA); and using Software as a Service (SaaS). They are all good ideas and can save significant amounts of money. In the current economic climate, enterprises are most likely considering one or a combination of these technologies. The wide area network (WAN) becomes even more important than usual for an enterprise because every one of the above ideas requires a robust WAN. The problem is that these technologies put pressure on the WAN when resources for it are tight. WAN managers will have to invest in their WAN in 2009 to handle these new demands, but they must do it intelligently. Throwing money at the problem in the form of bandwidth upgrades is not the answer. There is little extra money to be found, and if there were, that method is not the best solution. There are better ways to support WAN-intensive projects. CONSOLIDATING BRANCH OFFICE SERVERS The most common and biggest money-saving project that enterprises are embarking on is server consolidation. Moving branch office servers to a central data center saves money in many ways. The first is by reducing hardware cost. Branch office server utilization is generally below 25%, and there is little that can be done to improve that. Moving several servers to the data center and using virtualization software allows multiple branch office servers to be consolidated into one physical server. Consoli- 2 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT a CHAPTER 3 DEPLOYING WAN OPTIMIZATION dating servers saves on hardware cost and software licenses and provides a greener and lower-cost solution because it requires less power and cooling. It also makes maintenance easier because all the servers are located in one place. Disaster recovery becomes easier, as well, because the servers easily fit into the data center’s disaster-recovery scheme, rather than being dispersed. Overall, consolidating branch office servers in the data center is a winner and a trend that will become even more common in a down economy. The problem with a consolidation project is its effect on the WAN. Data that was local to the user and retrieved over a high-speed local area network (LAN) now must cross the WAN. Normally, this means that bandwidth must be increased. But even with increased bandwidth, there can be response-time problems that speed alone will not solve. The main problem is the Common Internet File System (CIFS), the protocol Microsoft uses to allow programs to make requests for files and services on remote computers. Initially, it was very inefficient over the WAN. For example, when CIFS downloaded a file, it asked for a block of data and then waited for an acknowledgment before asking for the next block of data. This inefficient protocol was not a problem over a LAN because it involved almost no latency. Over the WAN, it created a slow start-stop process, which greatly increased file download time. Recent improvements to CIFS allow it to ask for multiple blocks of data at once, increasing its efficiency. That has not completely eliminated the start-stop process over the WAN and long downloads, however. Another problem that server consolidation introduces is the effect on some of the services that the servers The problem with consolidation is its effect on the WAN. Data that was local on a high-speed LAN must now cross the WAN. provide to local users. Local servers provide Dynamic Host Configuration Protocol (DHCP), domain name system (DNS), and activity directory services and support printing to local printers. Moving these services to the data center does not enhance them or provide any significant benefit and instead can introduce problems. If the link to the data center is down, then branch office users are prevented from performing any networking functions. Even if there are still local servers or alternate routes to the Internet, users can’t take advantage of them without DHCP or DNS. Having a good backup path in the WAN is an important strategy, and if problems do occur it will be necessary to have DHCP and DNS functions locally. Even if the link is up, routing a print job to the data center and then back 3 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN to the branch office’s local printer is a waste of resources. However, these problems and their impact on the WAN or local services are not reason enough to stop server consolidation when the total cost savings picture is considered. Instead, WAN managers must find ways around the problems. a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY OVERCOMING SERVER CONSOLIDATION CHALLENGES a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT The answer is acceleration and optimization. This is accomplished with devices commonly referred to as WAN optimization controllers (WOCs). WAN optimization is a symmetrical solution, which means a WOC must be installed in each branch office and in the data center. The WOC in the data center supports multiple branch office WOCs, with the exact ratio of branch office devices to data center devices depending on the capacity of the data center WOC. WAN optimization solves data center problems with a combination of technologies. The need for increased bandwidth is solved by compressing data using a technique commonly referred to as dictionary compression. Dictionary compression can easily reduce the amount of data sent by a factor of five to 10 times, with reduction rates as high as 20 to 30 times. Lines running at 75% capacity can be reduced to less than 10%. Server consolidation bandwidth requirements can fit within the existing bandwidth. This is not hype; independent industry tests and user experiences have confirmed that these rates and reductions are possible. Dictionary compression achieves its high reduction rates by learning patterns in the data and substituting a CHAPTER 3 DEPLOYING WAN OPTIMIZATION WHAT’S THE MOST CHALLENGING ASPECT OF WAN NETWORKING? 3.18% Interfacing with other IT departments 5.68% Integrating multiple carrier services/links 8.64% Administration of branch office systems 16.36% Minimizing downtime SOURCE: SEARCHNETWORKING WAN READER SURVEY, 12/08; N=440 27.73% Application performance 18.64% Managing/predicting the volume of traffic 18.41% Security 4 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN a reference number for the patterns. As data is passing through the WOC, it breaks the data into a series of patterns and stores them, creating a dictionary of patterns. When the next message comes through, the WOC a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY WAN managers must carefully understand how appliances handle SSL traffic to ensure it is the best fit for their environment. checks to see whether any of its stored patterns matches patterns in the message. If it finds them, the WOC removes the patterns and substitutes reference numbers in their place. The WOC on the receiving end removes the reference number and replaces it with its copy of the pattern from its dictionary. The patterns do not have to be exchanged between the two WOCs because they are learning and storing the exact same pattern, using the same reference number independently. For example, if a user retrieves a file from a server that he accessed the day before, then the WOC need only send a series of reference numbers. That’s because the file was turned into a pattern the first time it was retrieved. If a section of the file has changed since it was last retrieved, then the WOC sends the reference numbers for the part that hasn’t changed, along with the small part that has. This example uses the same file but the patterns can come from other messages as well; the WOC uses its entire dictionary of patterns to find a match. Replacing patterns with reference numbers also reduces the number of packets sent over the network because the WOC can bundle reference numbers from multiple packets into one. Dictionary compression works only on uncompressed data or un-encrypted data. There is no reduction with video and voice since those media are already compressed. The best action for WAN optimization is not to waste time trying to compress it. a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT HANDLING ENCRYPTED TRAFFIC a CHAPTER 3 DEPLOYING WAN OPTIMIZATION Encrypted data, such as SSL traffic, is too random and a poor candidate for compression. Most WAN optimization appliances get around this problem by first un-encrypting the SSL traffic, compressing it and then re-encrypting it. The two endpoints never know this happens and thus require no changes. How the WOCs perform the de- and re-encryption differs from vendor to vendor. WAN managers must carefully understand how appliances handle SSL traffic to ensure it is the best fit for their environment and works with their key management system. Reducing the size of the data generated by server consolidation solves only part of the problem created by server consolidation. Response time is still affected by the inefficiencies of 5 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT a CHAPTER 3 DEPLOYING WAN OPTIMIZATION the CIFS protocol. WOCs solve this problem by optimizing CIFS. CIFS works as an end-to-end protocol between the application running on the user’s PC and the Microsoft server. WOCs optimize it by first breaking the end-to-end nature. The WOC in the branch office acts like the server to the user’s PC, and the WOC in the data center acts like the user to the server. An example best demonstrates how this will improve response time. When a user requests a file, the server sends several blocks of data to the PC. After the PC has received the blocks of data, it sends an acknowledgment back to the server, which tells the server to send the next block of data. The latency of the WAN causes the file to take longer than it did over the LAN because the server has to wait a lot longer for the acknowledgment to make its way back. The WOC overcomes this problem by stepping into the middle of the process. When the PC requests the file, the WOC passes the request to the server. The server then sends the blocks to the WOC, which immediately passes them onward to the PC. But at the same time, the WOC immediately sends an acknowledgment back to the server, acting as if the PC has already received the first blocks. This causes the server to immediately send the next blocks of data. The process continues, with the data center WOC quickly getting the entire file and sending it on to the WOC at the branch office. The WOC at the branch office sends the first block of data to the PC, which sends an acknowledgment. Instead of passing this acknowledgment back to the server in the data center, the branch office WOC sends the next block of data, acting as if it is the server. The Although the WAN is more burdened than ever before, optimization helps send more traffic over the same links. key is that the two WOCs are keeping the acknowledgments local and quickly receiving and sending the blocks of data. This improvement can make files appear to be local to the user, solving the response time problem of moving servers to the data center. The final major hurdles for server consolidation are the services, including DHCP, DNS, active directory and local printing. WAN optimization venPHOTOGRAPH: PHOTOS.COM 6 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN dors have either engineered their own versions of these servers or partnered with Microsoft to achieve this functionality. Most WOCs can act as if they are Microsoft servers for these functions, keeping them local. Since each vendor’s implementation is unique to its product, WAN managers need to understand how they fit within their environments. a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY VDI AND HTTP a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT a CHAPTER 3 DEPLOYING WAN OPTIMIZATION WAN optimization also solves the problems associated with implementing virtual desktop infrastructure (VDI) and Web-based applications. The major problem with VDI, the practice of hosting a desktop operating system within a virtual machine running on a centralized server, is that large amounts of data must be transferred quickly over the network. That problem is solved by dictionary compression. Object caching combined with dictionary compression reduces the bandwidth impact and greatly improves response time for Web/ HTTP traffic. Web pages are based on objects; each item on the page is an object. Rich media objects make Web applications appealing to users, but they generate significantly more data than the client/server applications they replace. WOCs can reduce the impact of these rich objects, because it is common for the same object to be used on multiple pages or accessed frequently by the same users. The WOC stores a copy of the object, and when a page requests an object that the WOC already has in its cache, it sends its copy. This also addresses an HTTP protocol efficiency that has an impact on response time. The Web application may serially request the object as it builds a page. It waits until the first object is received before asking for the next object. Because the objects travel over the WAN, the WAN latency increases the page’s response time. Using the objects in the WOC’s cache mitigates the problem because the WAN latency is removed. Overcoming Web and VDI challenges means enterprises can move ahead with money-saving projects and productivity-enabling applications, in many cases avoiding bandwidth upgrades. Response time problems are eliminated. COLLABORATION AND VIDEO ON THE WAN The current tight economic times mean businesses must be more productive. Collaboration is a proven productivity and creativity enhancer. The problem with face-to-face collaboration is that traveling for live meetings is both expensive and a time waster. The solution is more collaboration using the WAN. Unified communications, including collaboration and conferencing tools, can provide enterprises with significant cost savings and an increase in worker productivity but create more traffic on the WAN. The effects of tools such as Web conferencing, 7 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT a CHAPTER 3 DEPLOYING WAN OPTIMIZATION social software, document sharing, whiteboarding and team workspaces can be managed using WAN optimization. Collaboration using video must be treated differently, however. Telepresence, with its high-definition video, allows meetings over the network to have the same look and feel as being there. Even lower-resolution video conferencing is better than a traditional phone call. Collaboration puts a premium on a high-functioning WAN. There is no way to avoid upgrading WAN bandwidth to support telepresence because it requires megabits of bandwidth. Dictionary compression and protocol improvements do not help with video. Video is already compressed as much as it can be, and there are no problems with the protocol used. WAN optimization can help if an enterprise is using video that is static rather than real-time collaboration. Some WOCs have limited content delivery networking (CDN) functions built in and can store video locally. Thus, when multiple users view it at different times, the video doesn’t have to be resent over the WAN each time. This helps primarily with video such as training and corporate announcements. Another feature found on WOCs is the ability to know whether several people at a site are watching or participating in the same video Collaboration puts a premium on a high-functioning WAN. stream. The data center WOC will send only one stream to the WOC at that site, and then the local WOC sends the stream to each of the viewers. The reality is that WAN optimization can do little to reduce the impact of video on the WAN. If a real-time collaboration project including video is planned, WAN managers must be sure that necessary bandwidth increases are part of the proposal. The primary challenge is to support all the traffic generated by collaboration without affecting other missioncritical business traffic. I ABOUT THE AUTHOR Robin Layland is President of Layland Consulting. As an industry analyst and consultant, Robin has covered all aspects of networking from both the business and technical side, and has published over 100 articles in leading trade journals including Network World, Business Communication Review, Network Magazine and Data Communications. Prior to his current role, Robin spent a combined fifteen years at American Express and Travelers Insurance in a wide range of jobs including network architect, technical support, management, programming, performance analysis and capacity planning. 8 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN RESOURCES FROM OUR SPONSOR q Whitepaper: “Resolving Application Performance Problems with Unified Performance Management” q Demo: View a 2 minute demo of Exinda WAN Optimization q Whitepaper: “Controlling Recreational Peer-to-Peer Traffic on the Network” q Product information is available at: http://exinda.com/public/solutions.html?EB q Whitepaper: “Best Practices in Optimizing WAN Performance” About Exinda Networks: Exinda Networks is a global supplier of WAN optimization and bandwidth shaping solutions that help organizations achieve predictable application performance. Founded in 2002, Exinda facilitates optimal and consistent application performance over the WAN. Exinda integrates traffic visibility by application, bandwidth shaping, application acceleration and application response measurement into a single appliance. Exinda has helped more than 2,000 customers worldwide to reduce network operating costs by eliminating the need for expensive bandwidth upgrades. 9 THE ULTIMATE GUIDE TO GAINING CONTROL OF THE WAN CHAPTER 2 1 Leveraging WAN resources with skillful WAN management a CHAPTER 1 WAN INVESTMENTS THAT SAVE MONEY Discover why application awareness and comprehensive monitoring are critical to ensure your WAN is functioning optimally and to its fullest capacity. BY ROBIN LAYLAND a CHAPTER 2 LEVERAGING WAN RESOURCES WITH SKILLFUL WAN MANAGEMENT..."

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