WAN optimization

<h2 id="wan-optimization-techniques">WAN optimization techniques</h2>
<a href="/facts/Data_deduplication/sHuJ8zya">Deduplication</a>
Eliminates the transfer of redundant data across the WAN by sending references instead of the actual data. By working at the byte level, benefits are achieved across IP applications.
<a href="/facts/Data_compression/gMFuY4FT">Data compression</a>
Relies on data patterns that can be represented more efficiently. Essentially compression techniques similar to ZIP, RAR, ARJ etc. are applied on-the-fly to data passing through hardware (or virtual machine) based WAN acceleration appliances.
Latency optimization
Can include TCP refinements such as window-size scaling, selective acknowledgements, Layer 3 congestion control algorithms, and even co-location strategies in which the application is placed in near proximity to the endpoint to reduce latency.<a class="footnote-ref" id="fnref:16" href="#fn:16">16</a> In some implementations, the local WAN optimizer will answer the requests of the client locally instead of forwarding the request to the remote server in order to leverage write-behind and read-ahead mechanisms to reduce WAN latency.
Caching/proxy
Staging data in local <a href="/facts/Web_cache/DqIBcWem">caches</a>; Relies on human behavior, accessing the same data over and over.
<a href="/facts/Forward_error_correction/cLUTUJrA">Forward error correction</a>
Mitigates packet loss by adding another loss-recovery packet for every N packets that are sent, and this would reduce the need for retransmissions in error-prone and congested WAN links.
<a href="/facts/Protocol_spoofing/EjNL65PX">Protocol spoofing</a>
Bundles multiple requests from chatty applications into one. May also include stream-lining protocols such as <a href="/facts/CIFS/pWM35pl8">CIFS</a>.
<a href="/facts/Traffic_shaping/VCF0Gb3b">Traffic shaping</a>
Controls data flow for specific applications. Giving flexibility to network operators/network admins to decide which applications take precedence over the WAN. A common use case of traffic shaping would be to prevent one protocol or application from hogging or flooding a link over other protocols deemed more important by the business/administrator. Some WAN acceleration devices are able to traffic shape with granularity far beyond traditional network devices. Such as shaping traffic on a per-user and per-application basis simultaneously.
Equalizing
Makes assumptions on what needs immediate priority based on the data usage. Usage examples for equalizing may include wide open unregulated Internet connections and clogged VPN tunnels.
Connection limits
Prevents access gridlock in and to denial of service or to peer. Best suited for wide open Internet access links, can also be used links.
Simple rate limits
Prevents one user from getting more than a fixed amount of bandwidth. Best suited as a stop gap first effort for remediating a congested Internet connection or WAN link.

<h2 id="references">References</h2>

<ol>
<li id="fn:1">Machowinski, Matthias. "WAN optimization market passes $1 billion in 2008, up 29%; enterprise router market down". Enterprise Routers and WAN Optimization Appliances. Infonetics Research. Retrieved 19 July 2011. <a href="http://www.infonetics.com/pr/2009/4q08-enterprise-routers-market-research.asp" target="_blank">http://www.infonetics.com/pr/2009/4q08-enterprise-routers-market-research.asp</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Skorupa, Joe; Severine Real (2010). "Forecast: Application Acceleration Equipment, Worldwide, 2006–2014, 2Q10 Update". Gartner, Inc. Retrieved 19 July 2011.[dead link‍] <a href="http://www.gartner.com/DisplayDocument?id=1387649" target="_blank">http://www.gartner.com/DisplayDocument?id=1387649</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Munch, Bjarne; Neil Rickard (2015). "Magic Quadrant for WAN Optimization, 17 March 2015". Gartner, Inc. Retrieved 26 March 2015. <a href="https://www.gartner.com/doc/3008618/magic-quadrant-wan-optimization" target="_blank">https://www.gartner.com/doc/3008618/magic-quadrant-wan-optimization</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Cardwell, N.; Savage, S.; Anderson, T. (2000). "Modeling TCP latency". Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064). Vol. 3. Dept. of Comput. Sci. & Eng., Washington Univ., Seattle, WA: IEEE.org. pp. 1742–1751. doi:10.1109/INFCOM.2000.832574. ISBN 0-7803-5880-5. S2CID 6581992. <a href="0-7803-5880-5" target="_blank">0-7803-5880-5</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">Jacobson, Van (October 1988). "TCP Extensions for Long-Delay Paths". Request for Comments: 1072. Internet Engineering Task Force (IETF). Retrieved 19 July 2011. <a href="http://tools.ietf.org/html/rfc1072" target="_blank">http://tools.ietf.org/html/rfc1072</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Floyd, Sally. "HighSpeed TCP for Large Congestion Windows". Request for Comments: 3649. Internet Engineering Task Force (IETF). Retrieved 19 July 2011. <a href="http://www.ietf.org/rfc/rfc3649.txt" target="_blank">http://www.ietf.org/rfc/rfc3649.txt</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">S. Jain; et al. (2013). "B4: Experience with a Globally-Deployed Software Defined WAN" (PDF). Retrieved April 4, 2018. <a href="https://cseweb.ucsd.edu/~vahdat/papers/b4-sigcomm13.pdf" target="_blank">https://cseweb.ucsd.edu/~vahdat/papers/b4-sigcomm13.pdf</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">C. Hong; et al. (2013). "Achieving High Utilization with Software-Driven WAN". Microsoft. Retrieved April 4, 2018. <a href="https://www.microsoft.com/en-us/research/publication/achieving-high-utilization-with-software-driven-wan/" target="_blank">https://www.microsoft.com/en-us/research/publication/achieving-high-utilization-with-software-driven-wan/</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">S. Kandula; et al. (2014). "Calendaring for Wide Area Networks" (PDF). Microsoft. Retrieved April 4, 2018. <a href="https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/sigc334-kandula.pdf" target="_blank">https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/sigc334-kandula.pdf</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">M. Noormohammadpour; et al. (2016). "DCRoute: Speeding up Inter-Datacenter Traffic Allocation while Guaranteeing Deadlines". Retrieved April 4, 2018. <a href="https://www.researchgate.net/publication/307888649" target="_blank">https://www.researchgate.net/publication/307888649</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">X. Jin; et al. (2016). "Optimizing Bulk Transfers with Software-Defined Optical WAN" (PDF). Retrieved April 4, 2018. <a href="http://iiis.tsinghua.edu.cn/~weixu/files/SIGCOMM-Jin.pdf" target="_blank">http://iiis.tsinghua.edu.cn/~weixu/files/SIGCOMM-Jin.pdf</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">X. Jin; et al. (2016). "Optimizing Bulk Transfers with Software-Defined Optical WAN" (PDF). Retrieved April 4, 2018. <a href="http://iiis.tsinghua.edu.cn/~weixu/files/SIGCOMM-Jin.pdf" target="_blank">http://iiis.tsinghua.edu.cn/~weixu/files/SIGCOMM-Jin.pdf</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">M. Noormohammadpour; et al. (2018). "Minimizing Flow Completion Times using Adaptive Routing over Inter-Datacenter Wide Area Networks". Retrieved April 4, 2018. <a href="https://www.researchgate.net/publication/323411017" target="_blank">https://www.researchgate.net/publication/323411017</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">M. Noormohammadpour; et al. (July 10, 2017). "DCCast: Efficient Point to Multipoint Transfers Across Datacenters". USENIX. Retrieved July 26, 2017. <a href="https://www.researchgate.net/publication/316921061" target="_blank">https://www.researchgate.net/publication/316921061</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">M. Noormohammadpour; et al. (2018). "QuickCast: Fast and Efficient Inter-Datacenter Transfers using Forwarding Tree Cohorts". Retrieved January 23, 2018. <a href="https://www.researchgate.net/publication/322243498" target="_blank">https://www.researchgate.net/publication/322243498</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">Paris, Chandler. "Latency & Colocation". Retrieved 20 July 2011. <a href="http://biztt.com/info/?p=23" target="_blank">http://biztt.com/info/?p=23</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></li>
</ol>

WAN optimization open-in-new

WAN optimization