wan virtualization transforming the enterprise...

A Talari Networks White Paper

A Talari White Paper

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WAN Virtualization – Transforming the Enterprise WAN

2 WAN Virtualization -‐ Transforming the Enterprise WAN

© 2009-‐2011 Talari Networks Inc.

Introduction IT departments face pressures to control costs while meeting increasing demands on the network. As applications’ thirst for bandwidth ever increases, centralizing servers and services reduces some costs, but places increased pressure on network reliability and response. New services such as VoIP and videoconferencing only further increase this pressure on network reliability and predictability.

Talari’s WAN Virtualization technology is doing for Enterprise Wide Area Networking what RAID did for storage – delivering a network with 30x – 100x bandwidth/$, monthly WAN costs reduced by 40% -‐ 90%, and with greater reliability than existing single-‐vendor private MPLS WANs.

In a carrier-‐pricing environment where a price/performance factor of 2x (50%) is enormous, WAN Virtualization as implemented in Talari’s Adaptive Private Networking (APN) technology brings Moore’s Law and Internet economics to Enterprise WAN buyers for the first time in 15+ years. Furthermore, a WAN Virtualization solution does this incrementally and seamlessly on top of existing networks – no forklift upgrades required.

Learning from the Storage Market

Where RAID wrapped a layer of hardware and intelligent software

around the PC hard disk, the intelligent software in Talari’s APN appliances does something similar with multiple WAN connections -‐ existing private WANs and high speed Internet connections (T3, OC3, Metro Ethernet, etc.) at data centers and large sites, as well as existing connections and any type of broadband Internet links for branch/smaller locations. See Figure 2.

Inexpensive Reliable

Figure 1: Raid Reliability

WAN Virtualization -‐ Transforming the Enterprise WAN 3


RAID leveraged that PC hard disk technology to revolutionize business storage cost, capacity and reliability. WAN Virtualization technology

leverages the most powerful, ubiquitous, low cost communications network ever created – the public Internet – to deliver Enterprise WANs that are far higher bandwidth and far lower cost, with more reliability and greater application performance predictability than the best proprietary single service provider WANs available today.

The WAN Price / Reliability Disconnect Over the last decade Internet connectivity has exploded and the associated economics have resulted in the more than 400 million broadband Internet subscribers worldwide. Moore’s Law, the growing demand for bandwidth from media-‐rich applications such as video, and competition between broadband providers are driving up the speed of these connections. Today many knowledge workers have more bandwidth at home than they do in the office – sometimes a lot more. The contrast with the market for private WAN bandwidth can be clearly seen in Figure 3. This chart plots different wide area services against their reliability and cost per megabit of bandwidth per month. Reliability in this case is the combination of network availability, plus the absence of packet loss and excessive delay from the applications perspective. Frame Relay was fabulous price/performance when it was introduced in early 1990s, much better than the X.25 and leased lines it replaced. As Frame Relay gives way to the improved, all IP cost structure of MPLS, business are seeing only modest reductions in the price of private WAN bandwidth. At the other end of the chart we see the highly competitive broadband Internet market. These connections are still quite reliable at somewhere around 99%. But, that small difference in reliability versus

Figure 2: WAN Virtualization via Talari’s Adaptive Private Networking



Frame Relay or MPLS is driving a thirty to one hundred times difference in bandwidth cost per megabit.

Carriers are able to get away with this 100 times difference in price per bit because broadband’s two nines (99%) reliability doesn’t meet the minimum three nines (99.9%) or four nines (99.99%) which enterprises expect for their private WANs. Business customers are conservative when it comes to their wide area connectivity, and rightly so due to the high cost of downtime. So given that one or two vendors in each country dominate the telecom service provider market, there has been little incentive to cut prices. It is this price versus quality disconnect that offers businesses the ability to significantly reduce their ongoing WAN expenditures, and simultaneously significantly increase their network capacity, by using WAN Virtualization to solve the Internet quality/reliability issue.

Reliable WANs Don’t Have to be Expensive For the last few years the only choices to connect a remote office have been either expensive leased lines, Frame Relay or MPLS, or to live with the variable performance and suboptimal reliability of an IP VPN over the public Internet. Now there is another choice that combines the best of all worlds. WAN Virtualization takes two or more disparate sources of IP bandwidth at each network location and combines them in a way that delivers reliability that meets or exceeds that offered by any single vendor Frame Relay or MPLS network. These bandwidth sources can be high-‐

Figure 3: WAN Price/Reliability Disconnect



Figure 4: Reliability of Two Paths in Parallel

speed T3, OC-‐3, or Gigabit Ethernet links at larger sites, as well as any Internet connectivity such as DSL, cable, FTTH, T1, T3, Metro Ethernet, etc. at remote locations. Existing private WAN connections such as MPLS can also be leveraged, as shown in Figure 2. With connectivity between locations possible over at least two paths from different network sources there is redundancy because of the diversity at the physical and the IP network levels.

The probability of being able to get a packet from one location to another across at least one of these networks in a timely fashion is very high. If each network has a reliability of only 98%, then the reliability of the two networks when combined properly using WAN Virtualization technology will be 1-‐((1-‐0.98) * (1-‐0.98))= 99.96%. Similarly, two Internet connections that are 99% reliable can be made 1-‐((1-‐.99)*(1-‐.99)=99.99% or ‘four nines’ reliable.

Usable Bandwidth is Inexpensive and Abundant Broadband connections are priced and sized differently than private WAN offerings. With WAN Virtualization, a site with a DSL connection plus a Cable Modem connection, together costing perhaps $100 -‐ $150 per month, can achieve four nines reliable connection back to the data center. Compare this to using an MPLS network with a T1 link at the site costing $750 per month. Besides costing a small fraction of the amount, the other key difference is that the remote office now has perhaps 5 to 20 times as much bandwidth! This is game changing for businesses that rely on applications that run over the WAN. Now remote offices can benefit from an order of magnitude more reliable bandwidth at a fraction of the traditional



cost. New applications such as videoconferencing become economically feasible, and IT infrastructure can be consolidated more aggressively.

Real-‐time Traffic Engineering for Network Predictability There are two key technologies that allow Talari’s APN WAN Virtualization solution to deliver these benefits.

Multipath Network Spectrometry

With Multipath Network Spectrometry, the characteristics of every WAN link, network path and traffic flow are monitored precisely and continuously. This yields detailed unidirectional data about instantaneous loss, latency, jitter and bandwidth utilization for each path between any two network locations.

Figure 5: Multipath Network Spectrometry



Resilient Multipath Connectivity

All of the possible paths through the network are monitored and utilized to improve the performance for all applications, maxim-‐izing the use of available bandwidth thanks to sub-‐second reaction to and mitigation of the effects of packet loss and jitter. This delivers predictable performance throughout, regardless of transient congestion or network outages. To TCP/IP based applications, the resulting WAN connectivity looks like a zero loss network with

occasional bouts of jitter.

With these two underlying technologies, APN appliances use end-‐to-‐end algorithms to match the state of the network with the needs of different traffic types and adapt using real-‐time, per-‐packet traffic engineering. This ensures that the optimal path is chosen for every packet. Even though packets can follow any number of paths to the destination, the connection between two locations appears as a single highly reliable link. In APN terminology, this is called a “conduit”. Like all good intermediate networking boxes, APN appliances implements QoS and use the class of service information and any other configured policy rules associated with each flow as part of the path selection criteria. Unlike other boxes that implement QoS and can only prioritize which traffic goes out on the local link first, Talari’s WAN Virtualization technology uses this QoS information to choose the path that gets the packet to the destination in the shortest possible time, which is ultimately what matters most. In a Talari APN conduit there can be up to 10 classes of service, and per-‐flow classification inside the APN appliance determines which class to use for each traffic flow. Consequently, there is enormous flexibility in how the bandwidth is used among real-‐time traffic,

Figure 6: Resilient Multipath Connectivity



interactive and bulk transfer application flows. The packets within a conduit are also secured using 128-‐bit AES encryption.

Using All of the Bandwidth Most of the Time Unlike traditional back-‐up circuits, all of the connections are used almost all of the time. Even packets from a single IP flow may be sent to the destination over different paths and sorted by the APN appliance at the destination. If network impairments are detected along any of the paths, traffic can be moved to an alternate path in a fraction of a second. [The actual time is a function of the round trip time (RTT) between the two locations and is usually less than 2.5 x RTT.]

Once a path returns to an acceptable level of performance, the APN appliances will respond within a second or two to add that bandwidth back into the conduit. So APN uses all of the bandwidth most of the time, most of the bandwidth all of the time, while always maintaining application performance predictability as good, and usually better than a single

This real data taken over 60 hour period from San Jose, California to Raleigh, North Carolina illustrates how the performance of paths through the Internet varies over time.

The state is logged down to the granularity of 1 minute.

Good = Acceptable Performance

Bad = Significant Packet Loss

Dead = No connectivity

Notice how the state of the conduit

marked with a black ‘+’ remains good despite the degradation in the underlying paths.

Figure 7: Path and Conduit State



MPLS network. Contrast this to a back-‐up VPN link for a primary MPLS network, which is left idle most of the time and when needed might have unpredictable network characteristics.

Handling Real Time Traffic Real-‐time traffic such as VoIP cannot normally be deployed reliably over the public Internet due to the lack of end-‐to-‐end QoS and the major impact of relatively small amounts of jitter and packet loss on voice quality. Even with sophisticated voice quality software and adaptive jitter buffers in the end equipment, it is almost impossible to guarantee toll quality throughout the duration of most calls. As a result, high quality business VoIP solutions today run over private networks owned by a service provider or the enterprise themselves. This allows the traffic engineering needed to ensure a low level of jitter and loss. With APN, the transient problems on the Internet are avoided by using APN’s real-‐time traffic engineering to select the optimal path between the sender and receiver on a packet-‐by-‐packet basis. At call set-‐up the path with optimal latency, loss and jitter is selected. If those characteristics degrade during the call, packets are immediately sent on a better path. With these changes happening sub-‐second, the user may not be able to perceive that the call was re-‐routed over a new path. APN can even go one step further, providing “platinum” quality for voice, by replicating real-‐time packets over two network paths and suppressing duplicates at the receiving APN appliance. Packets from the two real-‐time streams arrive at the destination with a few tens of milliseconds of each other, allowing the APN appliance to utilize packets from the secondary path if needed. This hides any loss or jitter on the path that was formerly the primary/better path. This technique trades the cheap bandwidth made possible by broadband Internet combined with APN WAN Virtualization technology for highly predictable voice performance. Given sufficient available bandwidth, the technique can be used for videoconferencing as well.



APN Deployment APN is deployed as an overlay network, so it integrates seamlessly with an existing network in a similar way to two-‐ended WAN Optimization solutions. Depending on the business needs, APN can be deployed conservatively or aggressively along one, two or all of the following 3 axes.

• Inexpensively Add Useable Bandwidth • Reduce WAN Operating Expense • Increase Reliability

Inexpensively Add Useable Bandwidth

As a first step APN can be used to add inexpensive Internet bandwidth to a remote location. Often remote sites already have an Internet link for local Internet access and/or for VPN backup for the primary private WAN connection. With APN this second link can be brought into service all of the time rather than just for emergencies or only for local web browsing. The low cost of broadband Internet links makes it particularly easy to add bandwidth inexpensively at remote sites. Add, say, just one 6 Mbps downstream, 768 Kbps upstream DSL to a 1.5 Mbps T1 MPLS connection and the corporate WAN bandwidth multiplies by 5x at that location. Adding three of those 6 Mbps results in 12x more bandwidth at the site.

Figure 8: Add Bandwidth



Reduce WAN Operating Expense

On this axis there are a broad range of approaches depending on how aggressively the enterprise wants to capture cost savings. As a first step a business could downsize their private WAN commitments by eliminating backup FR or MPLS circuits, using APN to both add bandwidth and ensure service continuity. The next step might be to reduce the amount of primary FR or MPLS bandwidth at each site and use proportionately more of the less expensive Internet bandwidth, which the WAN Virtualization technology now enables to be business quality. One of the side benefits of effective WAN Virtualization technology is that it must keep highly accurate information on the real performance of the paths across the Internet and the private WAN circuits used. So it is possible for businesses to look at the real data that shows the reliability of the resultant WAN Virtualization solution as compared to their MPLS network or individual Internet-‐based connections.

Increase Reliability

APN’s ability to use multiple active, load sharing connections between locations, with sub-‐second response to failure, packet loss or other congestion events, means that no single WAN link failure, or any single problem in the network, will cause a loss of connectivity. Even for those willing to pay for dual MPLS networks from different providers, WAN Virtualization provides a level of network reliability and application predictability unavailable using standard routed networks and routing protocols. With APN’s Multipath Network Spectrometry continuously measuring the state of all network paths,

Figure 9: Using Internet Bandwidth to Lower Costs



businesses avoid the possibility that their backup connection, which rarely is needed, itself has a problem or is incorrectly configured just when it is needed the most – when trouble does occur on the primary network. WAN Virtualization, in addition to reacting more quickly (sub-‐second) to hard network or device failures, where routing protocols can sometimes require up to 30 seconds to react, also protects applications from the performance problems which can occur due to loss or congestion on the WAN. While it is true that these “network brownouts” rarely occur on over-‐engineered North American MPLS networks, they do occur with at least some frequency in international MPLS networks, especially in the Asia-‐Pacific region. In fact, the inherent nature of APN to adapt in the face of WAN connectivity problems actually makes a WAN, once the WAN Virtualization solution has been set up, incredibly fault tolerant even to problems caused by a faulty software upgrade or incorrectly configured router on a business’ own network. A highly conservative company might conclude it is sensible to spend 60% of the WAN budget on expensive MPLS to provide perhaps 10% of overall network bandwidth, and 40% of their budget on inexpensive Internet bits to provide the other 90% -‐ a solution offering much higher reliability than MPLS alone at a lower overall price and with more bandwidth. A more aggressive cost reduction plan would look to eliminate expensive connections at most or all of the remote offices.

Beyond WAN Optimization Many companies have deployed WAN Optimization as a way to improve performance and defer bandwidth upgrades on their private WAN. WAN Virtualization and WAN Optimization are different but largely complementary technologies addressing the issues surrounding to how to improve wide area network performance. At the most fundamental level WAN Virtualization is about improving the performance of all applications over the WAN, by making cheap and abundant bandwidth reliable enough to use for business. In contrast, WAN Optimization assumes that WAN bandwidth is scarce and expensive and focuses on data deduplication (compression, caching) and application specific techniques to reduce the average bandwidth load on the WAN links. These WAN Optimization techniques generally only lead to a 2 to 4 times improvement in the price per bit benefit, versus 30 to 100 times for WAN Virtualization.



APN Complements WAN Optimization

Figure 10: APN as a Complement to WAN Optimization

Since WAN Optimization uses existing WAN links it can only free-‐up bandwidth with data deduplication; it will not provide more bandwidth, lower costs or increase reliability. However in combination, the benefits of WAN Virtualization and WAN Optimization are multiplicative. Adding bandwidth using WAN Virtualization means that all data transfers go more quickly, whereas WAN Optimization is really good at reducing the time for a ‘warm transfer’ where the data has all ready been cached or stored at the destination appliance. WAN Virtualization dramatically improves performance in times when the network is having issues with loss and jitter. WAN Virtualization will hide these issues from the WAN Optimization device. More bandwidth generally improves performance for most types of traffic, and WAN Virtualization-‐enabled bandwidth with predictable performance means that real-‐time and interactive applications work even better. WAN Optimization devices greatly improve the performance of Microsoft’s CIFS protocol, which often performs poorly over a WAN. Therefore, enterprises that have already deployed WAN Optimization can benefit greatly from the reliability, bandwidth increases and ongoing monthly WAN cost savings inherent in WAN Virtualization.



Conclusion WAN Virtualization solves the Internet reliability problem that has forced businesses to continue to pay very high prices for fairly limited private WAN bandwidth from their telecommunication providers. When combined with the incredibly low monthly cost per megabit per second of broadband Internet, WAN Virtualization technology can drastically reduce the ongoing monthly WAN operating expense for an enterprise. The market dynamics of broadband Internet have consistently improved Internet price/performance. Talari APN’s ability to aggregate multiple sources of this inexpensive bandwidth coupled with the sub-‐second response to network performance problems, delivers high reliability and more bandwidth to each site. Where once a branch office could only justify a 1.5 Mbps MPLS connection 6 Mbps, 20 Mbps or even more can now be provisioned at a fraction of the existing cost, providing overall higher WAN performance. Since WAN Virtualization can utilize multiple sources of IP bandwidth and combine them to provide a high bandwidth, highly reliable private network it is possible to migrate gradually away from existing private WANs. An enterprise can address issues at groups of sites that perhaps have issues with reliability or simply don’t have enough bandwidth, ultimately migrating partially or completely to WAN Virtualization to achieve significant cost savings. Where WAN Virtualization is used to replace an existing private WAN circuit altogether, or enables a reduction in the amount of bandwidth provisioned on an MPLS or Frame Relay network, it actually reduces the ongoing monthly WAN operating expense and pays for itself out of this hard cost savings. In a carrier-‐pricing environment where a price/performance factor of 2x is enormous, Talari’s Adaptive Private Networking technology for WAN Virtualization brings Moore’s Law and Internet economics to Enterprise WAN buyers for the first time in 15+ years. Furthermore, since WAN Virtualization does this incrementally and seamlessly on top of existing private networks, without requiring forklift upgrades, enterprises can take advantage of this powerful new technology at their own pace.

Talari Networks

550 S Winchester Boulevard, Suite 500

San Jose CA 95128

http://www.talari.com

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