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`Clarifying WAN virtualization, WAN aggregation and WAN optimization
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`http://searchenterprisewan.techtarget.com/feature/ClarifyingWANvirtualizationWANaggregationandWANoptimization?vgnextfmt=printGo
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`SearchEnterpriseWAN.com
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`2012
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`Clarifying WAN virtualization, WAN aggregation and WAN optimization
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`Talari Networks, a pioneer in the WAN virtualization industry, is often lumped together with WAN optimization solutions.
`Does this mean the technologies are the same? And how does WAN virtualization compare with WAN aggregation?
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`To understand the nuanced differences among these breakthrough WAN technologies, SearchEnterpriseWAN.com spoke
`with Andrew Gottlieb, founder and board member of Talari Networks. In this Q&A, Gottlieb explains how WAN
`virtualization contrasts with WAN aggregation and WAN optimization.
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`What is WAN virtualization?
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`Andrew Gottlieb: WAN virtualization is a twoended technology similar to the way [symmetrical] WAN optimization is
`deployed that enables network managers to use multiple WAN connections to augment or replace individual private WAN
`connections; [those connections can] be existing private WANs, such as MPLS, or Internet WAN links, like DSL, cable,
`fiber, Metro Ethernet, etc.
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`[WAN virtualization performs] bandwidth aggregation, allowing all links to be used almost all of the time. [It also] typically
`has lossmitigation capabilities to minimize the application performance impact of packet loss, latency or jitter. A well
`designed WAN virtualization solution does dynamic, realtime traffic engineering, reacting subsecond to not only link
`failures but also congestionrelated network problems. This enables enterprises to build a WAN with much higher bandwidth
`for a much lower cost than a singlevendor WAN based entirely on MPLS.
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`How does WAN virtualization differ from WAN aggregation?
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`Gottlieb: There is confusion here both because the term WAN aggregation or its equivalent multilink WAN aggregation
`is used sometimes for singleended technologies and sometimes for dualended technologies, and because even for dual
`ended technologies WAN aggregation can be used to describe simpler, special cases of what WAN virtualization delivers.
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`WAN virtualization is unrelated to the singleended definition of WAN aggregation, and is a superset of what's historically
`been delivered by products which do simpler WAN aggregation, most specifically in delivering excellent application
`performance and performance predictability in the face of network congestion problems that occur on shared networks like
`MPLS and especially the public Internet.
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`Note that all WAN aggregation and WAN virtualization technologies will correctly handle reliability when a network
`connection fails completely like when a WAN link dies, or a router fails. The more complex issue separating simpler
`WAN aggregation from WAN virtualization is handling connections with dissimilar latency, jitter and packet loss and, in
`particular, what happens in the face of network congestionbased changes in loss, latency and jitter.
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`What's an example of how WAN virtualization technology behaves in contrast to WAN aggregation?
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`Gottlieb: WAN routers supporting multiple WAN links, and using backup connections, are in some sense doing WAN
`aggregation, especially if you turn on balancing protocols like OSPF equalcost routing, but no one would really describe
`this as WAN virtualization. Any given flow is steered to a given route using some predetermined method. Other than in the
`case of link failure, all flows of that type will stay on that WAN connection.
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`FatPipe was perhaps the first company to deliver WAN aggregation technology focused on supporting WAN links with
`dissimilar loss [or] latency characteristics, like multiple public Internet connections. While it handles link failures very well
`and, in fact, has had some success in the small and mediumbusiness market, because it always stripes packets from every
`flow across all available WAN connections, it is almost guaranteed to cause application performance predictability problems
`whenever there is congestion on any WAN connection. For this and other reasons [it] has never really caught on in the large
`enterprise market. That said, whether or not one describes what FatPipe does as WAN virtualization is perhaps a matter of
`degree.
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`https://web.archive.org/web/20130308080758/http://searchenterprisewan.techtarget.com/feature/ClarifyingWANvirtualizationWANaggregationandWANopt… 1/2
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`FatPipe, Ex. 2005, pg. 1
`Talari v. FatPipe
`IPR2016-00976
`
`
`
`1/30/2017
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`Clarifying WAN virtualization, WAN aggregation and WAN optimization
`WAN optimization generally seeks to optimize each of many applications for the network, while WAN
`FEB
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`virtualization takes the approach of optimizing the network fabric for all applications.
`2 captures
`Andrew Gottlieb, Talari Networks Founder
`8 Mar 13 4 Jun 14
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`2012
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`WAN virtualization, from companies like Talari and Ipanema, goes behind traditional WAN aggregation in that it not only
`allows the use of multiple dissimilar WAN connections, but delivers excellent application performance and performance
`predictability even in the face of meaningful loss/latency/jitter events on the WAN. And [WAN virtualization] determines
`where to put traffic based on the current, realtime conditions of each network connection.
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`The best WAN virtualization implementations will allow you to use all available bandwidth even for just a single large flow
` like a file transfer or storagebackup application and can even move application traffic from one connection to another
`in real time in the face of network congestion, thus ensuring both maximum bandwidth utilization and predictable
`application performance.
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`It's the delivery of this predictable application performance in the face of an unpredictable network that enables enterprises
`to take advantage of inexpensive public Internet connections, including broadband connections which will see
`proportionally more episodes of network congestion than TDM links, and so makes WAN virtualization a much more
`comprehensive and valuable technology than simpler WAN aggregation technologies.
`
`WAN virtualization encompasses WAN aggregation, but delivers more in terms of reliability and performance predictability,
`especially in the general case of combining multiple dissimilar WAN connections.
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`How does WAN virtualization compare with WAN optimization? Are the two technologies complementary?
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`Gottlieb: WAN optimization technology, which has been widely deployed for the benefits it brings to server centralization
`[or] data center consolidation projects, combines diskbased data deduplication, applicationspecific help for Microsoft's
`CIFS protocol for file access, and some other TCP optimization techniques to save network bandwidth. [It] especially
`provide[s] application acceleration, which enables centralized server environments to deliver acceptable application
`performance.
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`WAN virtualization is highly complementary to WAN optimization. The majority of WAN virtualization deployments today
`add value on top of existing WAN optimization deployments. The bandwidth aggregation and lossmitigation capabilities of
`WAN virtualization deliver further benefits to WAN optimization deployments, providing better enduser performance for
`firsttime data transfers, and reliable voice and videoconferencing, as well as more predictable performance for all
`applications when any part of the private WAN becomes congested.
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`Where WAN optimization sees a reliable but expensive private WAN and seeks to squeeze every last bit of performance it
`can from the network, WAN virtualization sees lots of inexpensive, Internetbased bits out there, and seeks to make them
`reliable enough to be business quality. WAN optimization generally seeks to optimize each of many applications for the
`network, while WAN virtualization takes the approach of optimizing the network fabric for all applications.
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`For more information, listen to this podcast to understand WAN virtualization deployment and maintenance.
`
`13 Apr 2012
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`https://web.archive.org/web/20130308080758/http://searchenterprisewan.techtarget.com/feature/ClarifyingWANvirtualizationWANaggregationandWANopt… 2/2
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`FatPipe, Ex. 2005, pg. 2
`Talari v. FatPipe
`IPR2016-00976
`
`