Do More with MPLS: Ensure Application Performance

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1 Do More with MPLS: Ensure Application Performance Buy More Performance, Not More Bandwidth By John Burke Principal Research Analyst, Nemertes Research Executive Summary VoIP and collaboration tools, provisioned out of ever fewer data centers to an increasingly dispersed corporate environment, along with rising use of SaaS, drive bandwidth growth and rising need for predictable, stable, real-time WAN and Internet performance. To deliver new services to users in an evolving branch and telework environment, IT must compress, condition, and control network traffic to guarantee acceptable performance, and to ensure capacity goes to applications according to their organizational priority. IT needs more visibility into traffic too, if it is to set and meet realistic SLAs. Now is the time for organizations to set or refresh their optimization plans, to reassess architectural and vendor choices in light of new needs, and to look at combining approaches (asymmetric with overlay, carrier-cloud with symmetric) to best match solutions to resources and needs. The Issue: The Hunger for Bandwidth Two important trends have emerged that are changing the way organizations think about the WAN, Internet bandwidth, and application traffic on the network. They are the increasingly distributed enterprise and the rise of realtime and Internet-provided applications. Their growth drives steady increases in bandwidth, but as the traffic becomes more performance sensitive, additional bandwidth is not enough: the network must become more intelligent and more active in ensuring application performance. (Please see Figure 1: Mean Enterprise Annual Bandwidth Growth Rates, Page 2.) The Distributed Enterprise. Organizations continue to spread across space: between 2005 and 2008, the number of branch offices grew an average of 9.2 each year. At the same time, they provide IT services out of fewer and fewer locations. More than half (57) of organizations are committed to a fully centralized delivery model, and another 32 deliver most applications centrally even though they retain some distributed servers. Nemertes Research DN0738 1

2 120 Bandwidth Growth Figure 1: Mean Enterprise Annual Bandwidth Growth Rates Data center consolidation is also an issue, as organizations with many data centers strive to reduce the number. About 90 of users get enterprise applications over the WAN because of this increased centralization and consolidation and also because more are telecommuting. Yet regardless of location or how they re connected, users expect the same performance and reliability they would get when sitting at headquarters. With money tight, having applications run well on the WAN helps keep costs down. New Applications. Some of the most exciting and potentially transformative applications spreading through organizations now center on real-time, presence-enabled communications and collaboration tools, including Voice Over IP (VoIP), audio and video conferencing, and Web conferencing. Supporting collaboration tools to replace travel or to support a virtual workplace is a wise move, but real-time communications applications have very stringent WAN-performance requirements. (Please see Figure 2: New Applications Driving Bandwidth Needs, Page 3.) Other new applications that dramatically change long-distance network bandwidth and performance requirements include remote desktop access, and Software as a Service (SaaS). With 59.6 of organizations deploying some form of UC, and another 17 in the planning and piloting phases, optimization that is sensitive to the particulars of real-time voice and video traffic will become crucial. VoIP is most organizations first UC application, with 84.9 in some phase of VoIP deployment. Most roll-outs touch fewer than 50 of employees, currently. But as deployments proceed the WAN will have to become ever more capable of juggling the performance needs of many simultaneous real-time streams moving across a complete mesh of branches. Nemertes Research DN0738 2

3 Top Bandwidth Drivers Video/telepresence 36 New collaborative apps 29 New enterprise apps 27 More multimedia Web apps 25 Centralized apps 23 IP telephony Figure 2: New Applications Driving Bandwidth Needs Videoconferencing and high-resolution telepresence are following VoIP. Already, 77.6 of companies using video conferencing deploy room-to-room systems, and a growing number are adding desktop and telepresence systems. The economy and growing ecological awareness among organizations of all sizes combine to reinforce the spread of videoconferencing as a cost-saving and earthfriendly alternative to travel. In fact, 74 of those deploying videoconferencing can say with confidence that it is reducing their organizations travel time, and 47.8 have or are developing policies to promote videoconferencing to replace travel. Desktop conferencing, present in 52.8 of organizations, increases the number of video streams to juggle and the number of endpoints involved in the conversations. Telepresence, in place in 27.8 of organizations, is also tougher than standard room-based conferencing since it requires more bandwidth and even better network behavior with respect to packet loss and jitter. (Please see Figure 3: Enterprise Adoption of Video Conferencing, Page 4.) SaaS is also transforming enterprise IT, with 59.1 of organizations using SaaS now and another 9.1 evaluating. (Much conferencing traffic involves Internet sites such as GoToMeeting or WebEx, rather than internal sites.) SaaS traffic entangles critical network bandwidth and performance considerations for the WAN and the Internet. For 57 of organizations that do some direct branch connectivity to the Internet, SaaS performance depends on Internet performance only, where they have direct-to-net service, while in-house applications depend on Nemertes Research DN0738 3

4 WAN performance. But few organizations have direct Internet connections in all locations, and for those branches that don't -- as well as the 28.6 of organizations that backhaul all Internet traffic through the WAN -- Internet and WAN performance are linked. Although all of these changes in the enterprise and in applications have driven (and will continue to drive) a steady increase in bandwidth, bandwidth is not the only consideration. Even in situations where enough bandwidth is available, lack of conditioning of the bandwidth can be crippling, especially to applications such as desktop video conferencing that need a well-behaved link for acceptable performance. IT must somehow mitigate the effects of latency and packet loss, the banes of voice and video communications, and thereby improve the performance and response time of applications delivered over the WAN. Application response time is the key, says the senior architect at a large energy company. Moreover, organizations need more than just capacity and conditioning, they need visibility and control: the ability to ensure capacity is going to applications according to their priority to the organization. They often need to prioritize traffic in fairly granular ways. For instance, access to critical SaaS applications must take priority over basic Web browsing or even over other, lesscritical SaaS services. Siebel CRM access should not suffer because there is a new American Idol video on YouTube Videoconferencing Adoption Using Evaluating Not Using Desktop Room-based Telepresence Figure 3: Enterprise Adoption of Video Conferencing Nemertes Research DN0738 4

5 The bottom line: Users expect optimal performance wherever they are, regardless of which application they are using. Network capacity is part of the solution but not all of it; the networks must become more intelligent and more active in ensuring application performance if IT is to meet user expectations and the needs of the business. Keep Buying Bandwidth, or Use What You Have Better As mentioned, throwing bandwidth at connections is not enough, and perpetually costs a lot. Adding bits per second doesn't eliminate latency or make a bad application protocol deal with WAN as opposed to LAN distances. Organizations need to look at making the connections they have work better for them. Making it possible to work within existing bandwidth, or to at least slow the rate of increase, is the business of WAN optimization. If performance, and not bandwidth, is the only problem, and if the performance problems relate only to real-time communications versus other traffic, it may be possible to address those problems using existing class-ofservice/quality-of-service features in core network routers. By putting communications traffic in a "real-time" priority class, for delivery before other packets, many organizations can address problems with intermittent packet loss and jitter in their voice and video traffic. However, QoS systems are not very granular - they typically only allow four classes of service, for example. If the organization needs finer grain control of their traffic then QoS alone will not solve the problem. Also, there are kinds of latency that QoS can't help with: QoS does nothing to ameliorate the latency introduced by distance, and cannot reduce latency associated with delivery of large packets. Optimization systems, on the other hand, can provide additional granularity, and can sometimes mitigate these other forms of latency as well. Another great benefit, apart from the problems that optimization can solve that adding bandwidth cannot, is cost reduction. An organization can usually costjustify deploying WAN optimization just by looking at the ability to avoid or delay bandwidth upgrades. Consider a typical organization with a few T1-level WAN links. (Please see Figure 4, Basic Optimization ROI, Page 6.) Faced with a need for more WAN capacity, they planned to bump up from T1 to T3 rates, at a quadrupling of costs. By bringing in WAN optimization instead, even including all the costs of testing, installing, and maintaining the gear, they saved about $130,000 in the following year! Optimization Techniques Optimization uses various techniques to reduce traffic volume and improve application performance: content caching and data compression reduce volume, while protocol accelerations, prioritization, and traffic shaping control and improve application performance over the network. Nemertes Research DN0738 5

6 Implementation on Four Cross-Country T1 Circuits FTE Hours or Quantity Cost per hour/item Cost Evaluation 2 60 $ 39 $ 4,680 Consulting $ 10,000 Pilot $ 39 $ 12,480 Engineering 1 30 $ 39 $ 1,170 Implementation 2 30 $ 39 $ 2,340 Capital 4 $ 10,000 $ 40,000 Start-up $ 70,670 Annual Operational 2 10 $ 39 $ 9,360 Annual Licensing 14 $ 5,600 Operational $ 14,960 First year costs $ 85,630 Annual Monthly T1 cost 4 $ 1,500 $ 72,000 Monthly T3 cost 4 $ 6,000 $ 288,000 Monthly upgrade avoidance 4 $ 4,500 $ 216,000 Figure 4: Basic Optimization ROI CIFS is very latency sensitive because of the way it relies on request/response chains to move data around. Accelerators can tinker with the mechanics of the conversations in various ways to remove the chattiness of SMB and so ameliorate the effects of the added latency. TCP adopts a very brutal flow-management algorithm: If the network or the receiver can't handle the flow speed at which the sender is working, perhaps indicated by packet loss, the flow will drop to half that rate, and if that is still too fast, it will drop by half again, and so on. Speeds ramp up again, but only very slowly by comparison, giving the traffic a sawtooth look. So, performance of TCP applications that generate long packet flows, such as media streaming, can suffer hugely over WAN connections. Accelerators, either by helping the network avoid packet drops or by tinkering with the TCP flows directly and adjusting dropback/ramp-up behaviors, mitigate this kind of performance problem. Traffic Shaping and Prioritization. Modification of flow controls on TCP streams is one of the techniques used to shape traffic. Traffic shaping aims to Nemertes Research DN0738

7 ensure that an organization has some control over how applications consume available bandwidth. Control can be positive, guaranteeing that certain applications, devices, or users get bandwidth, or negative, limiting the bandwidth that specific users, devices, or applications get. Other techniques include queuing (parking packets in buffers, or queues, to await delivery after higher priority packets), connection-closing (sending a close packet to one or both ends of a stream, to shut it down), and selective packet dropping (creating artificial packet loss, to stop ramp-up or force step-down on a TCP stream's speed). Optimization Architectures There are four types of WAN optimization, defined by the optimization system s position in the network: symmetric, asymmetric, carrier-cloud, and overlay. Symmetric optimization requires an optimizer at both ends of a connection in order to function. The end points can be dedicated appliances, embedded functions in a multi-function device, or even software running on servers or on a user's computer. Because symmetric optimizers control both ends of a traffic stream, they can do more significant compressions and accelerations. However, putting something at both ends of connections, especially when that something is dedicated hardware, adds cost and complexity that grows as the network grows, increasing the management burden of IT. Soft clients may or may not cost extra on a per-seat basis, but because they usually run on a PC, they increase complexity and support burdens in the form of helpdesk calls. Asymmetric optimizers only control one end of a connection. Optimizations that don't require special clients on the other end include some protocol accelerations, traffic shaping, and compression of Web content, since Web browsers have the ability to decompress content which has been compressed, using a few standard techniques. Many asymmetric optimizers incorporate features aimed at offloading work from Web servers, and for load balancing among them. Some include security functionality as well, such as application firewalls for Web apps. Because they are deployed only in the data center end of the network, asymmetric optimizers don't have the same capital or management overhead that come with broad deployments of symmetric devices and they can serve arbitrary end users, not just those with company computers. However, they cannot compress traffic as much or perform all the accelerations possible with symmetric devices. Carrier/cloud optimization employs the same technologies as an enterprise might deploy in-house (compression, protocol acceleration, and so on). Volume-reducing functions such as compression have to happen in customerpremises equipment (CPE) managed by the carrier, since the point of reducing volume is to minimize bandwidth to the carrier. Behavior-based functions such as protocol accelerations or packet-loss mitigation can take place in the carrier's internal network. The carrier can install optimization gear for traffic shaping or protocol acceleration wherever it makes the most sense in their network, avoiding Nemertes Research DN0738

8 the complexity and cost of CPE, which can be attractive for organizations with lots of small branches. A managed solution can have lower start-up costs, making it a choice worth examining closely in recessionary times. A managed service is also typically quicker to get up and running, handy when needs change unexpectedly. Because they are lighter-weight organizationally, requiring less lead time, less internal expertise, and no capital investment, they allow easier layering of new solutions on top of or alongside existing in-house deployments. Overlay optimization consists primarily of separating the traffic to be optimized from the rest of the WAN traffic and sending it over a dedicated network. Like the high-occupancy vehicle lanes on some highways, overlay networks speed the delivery of content mainly by letting it avoid other traffic. Caching is another key feature of an overlay network, as most focus on delivering streaming media content. It is this focus that constitutes the main shortcoming of overlay optimization: limited scope. Most providers can't do much beyond optimizing content delivery to Internet-connected users, although some providers now offer server offload too, e.g. by handling media format conversion. A few are also branching into hosting of content-intensive or high-transaction applications. Conclusions and Recommendations VoIP and collaboration tools such as voice and video conferencing are sweeping through organizations, provisioned out of ever fewer data centers as IT centralization and consolidation proceed. These along with other new applications, SaaS and the increasingly dispersed corporate environment are driving bandwidth growth and rising need for predictable, stable, real-time performance. To deliver new services to users in an evolving branch and telework environment, IT may need to compress traffic to conserve bandwidth, but must condition network traffic to guarantee acceptable performance. The organization must also control traffic to ensure capacity goes to applications according to their organizational priority, and not to recreational or social media sites. IT also increasingly needs visibility into traffic (as well as control over it, and the ability to condition it) to meet user expectations and business-line SLAs. Now is the time for organizations to take a close look at their WAN and make their optimization plans. Organizations should: Save money by better managing what they have, evaluating users populations and new application requirements against current WAN and Internet performance. Expect an increase in real-time and fault-intolerant traffic, if not an increase in actual bandwidth required. Consider optimization technologies and architectures Weigh premises solutions versus managed offerings Be prepared to upgrade, replace, or supplement current solutions for new use cases or traffic types. Nemertes Research DN0738

9 Optimize for the shift in traffic flows as a result of IT centralization and data center consolidation. Control, monitor, and optimize traffic with SaaS providers and other direct-to-internet branch traffic. Plan on providing optimization and security to progressively more numerous and smaller endpoints: big branches become mini branches, become teleworkers. Cheap hardware or robust managed or carrier services, or affordable soft clients are key. Don t forget that optimization is about management; you can t manage what you can t see About Nemertes Research: Nemertes Research is a research-advisory firm that specializes in analyzing and quantifying the business value of emerging technologies. You can learn more about Nemertes Research at our Website, or contact us directly at research@nemertes.com. Nemertes Research DN0738