The enterprise WAN is evolving. Connectivity between the enterprise and remote branch has been historically achieved through private leased line connections. Because these connections are expensive, bandwidth is often limited to what is affordable, often resulting in congestion, contention, and performance issues at the remote site. The tried and true method for resolving this problem has been the addition of WAN optimization controllers (WOCs), which were originally designed and targeted at helping improve performance of specific traffic protocols such as CIFS. Various techniques were used to compress, cache, and de-duplicate traffic traveling through those connections, and this approach remains effective for improving performance over leased lines even today

The availability of broadband and increased use of mobile smart devices for work is changing the nature of remote connectivity. With leased lines, the IT administrators had some degree of visibility and control over the point of origin, the path and end points. That is changing as more enterprise traffic is traveling over public Internet connections. This presents more choices for achieving WAN connectivity, but at the same time creates new challenges around visibility, security, and performance.

New Paths of Choice

With broadband so readily available, it is increasingly common for a company to have both leased and broadband connectivity at a remote site. There are multiple ways to approach the use of such mixed connectivity. One approach is to keep business critical, latency sensitive traffic over the leased lines and move all other traffic to the broadband connection. Another approach is to aggregate those links and treat them as a single pipe back to the datacenter. The idea of WAN bandwidth link aggregation across multiple disparate WAN links is not new. Talari Networks has been touting this approach for five years. The approach takes advantage of all the available WAN connectivity at the site whether it is leased or broadband and redirects traffic according to bandwidth usage. Ipanema has been another popular optimization solution among service providers and has a Dynamic WAN Selection feature that has been part of their solution since 2011. As this hybrid approach to WAN connectivity has grown in popularity, vendors such as Riverbed and Silver Peak have jumped on board as well. In July 2013, Riverbed added a path selection feature to its RiOS 8.5 Steelhead operating platform. On December 4, 2013, Silver Peak announced Dynamic Path Control.  WAN bandwidth aggregation enables companies to take advantage of all the available WAN connectivity resources while at the same time providing insight and control over WAN link usage.

Private Internet Overlays

Companies such as Aryaka, Akamai, and Limelight have built globally distributed private networks that leverage the public Internet. The first generation solutions where known as Content Delivery Networks (CDNs) whereby vendors built their own globally distributed private networks that included local points of presence (POPs) to reduce the number of hops it took to traverse the public Internet. This type of solution has been very popular with web-based companies looking to improve end user customer experience, but has since expanded to include business connectivity services, including video streaming, service analytics, website optimization, traffic shaping, security, and WAN optimization. Akamai, one of the original CDN vendors, has shifted its focus to include a wide range of business connectivity services that cover mobile, media, enterprise (including WAN optimization), security, and carrier solutions. Aryaka is a relative newcomer with a focus on leveraging its private network solely for enterprise WAN optimization. Aryaka deploys WAN Optimization technology at each of its POPs and has layered a variety of application and network optimizing capabilities on top of the private core network. These private overlay solutions provide a way to supplement, compliment or replace WAN connectivity to mobile users and remote sites.

Client-side Optimization

Most if not all of the traditional WAN optimization vendors offer a client endpoint optimization solution that either works with their appliances, or in a standalone mode, and typically make use of local storage on the device for caching to reduce the number of round trips to the datacenter. Other approaches such as IPQ from LiveQoS focus specifically on improving the mobile experience. IPQ uses a client-side standalone agent, optimize connectivity, and is targeted at OEMs of mobile devices and applications.

The Cloud

Unlike SDN, which is still evolving, companies have moved from evaluating to mandating cloud deployments. Cloud deployments that include components such as public cloud or third party SaaS components change the point of origin from under the direct control of internal IT administration. This can limit end-to-end visibility and control. In some cases it effectively makes everyone a remote user and it behooves organizations who are looking to deploy cloud and SaaS solutions to find out if WAN optimization is built in or available as an add-on service. It is important not to throw out lessons learned in dealing with WAN connectivity issues. If the access point for an application or service is moved to a third party then it is highly possible some (if not all!) remote locations will be at a disadvantage from a performance standpoint, depending on how the service provider has built out their network. For example, if the service provider’s datacenters are just located in a single geography then offices located outside that geography might find they are experiencing unacceptable levels of latency.  EMA has learned of examples where extraordinary measures had to be taken to make up for the inability of well-known SaaS vendors to provide acceptable performance guarantees precisely along these lines.

In Summary

Today there are more choices as to how remote sites and mobiles users can connect back into the corporate datacenter, however the need for those connections to be secure, reliable and with acceptable levels of performance remains critical. The original WAN optimization market grew out of the need to improve traffic flows over expensive leased WAN links between fixed datacenters and remote sites. This method is still valid and provides a secure and proven approach. However cloud, ubiquitous broadband Internet access, and mobility create new challenges and require rethinking about how to build secure and reliable WAN connectivity without creating a performance penalty for end users.

There is no one size fits all solution since it is most likely there will be multiple use cases within a given organization. In each case it is important to understand the type of traffic, the source and destination, and which optimization solutions fit best for a given deployment and budget scenario. Having separate leased lines and broadband for remote site WAN connectivity is not as efficient as aggregating those links and then managing them as a single resource in which all traffic can be monitored and tracked. This provides the added benefit of building a clear picture of how WAN links are being utilized and help with planning and future deployments. With all the good and effective options for optimizing WAN links that are now available, it is an ideal time to go back and evaluate what options might already exist that are not being utilized. Improved performance over WAN connections could be just a mouse click away.

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