Put the Pedal to WAN Metal

Tech Analysis: WAN accelerators provide a bandwidth boost to remote users.

As the number of remote users and business partners has increased, so, too, has the need to make their computing experience as seamless as if they were on the corporate LAN.

Indeed, there are many business cases and scenarios in which WAN acceleration products could be extremely beneficial, which is why eWEEK Labs expects the technology to become more broadly adopted in the next few years.

Common file sharing and application protocols function well in LAN environments, but they slow to a crawl when clients try to access large files and attachments over a WAN link.

Throwing bandwidth at the problem often doesnt improve performance because the chattiness of these protocols prevents the network from running at its full potential.

/zimages/1/28571.gifClick here to read a review of Riverbed and Blue Coat WAN acceleration solutions.

The effects of this chattiness are even more pronounced when network traffic must go across the globe to outsourcing and business partners thousands of miles away. At these kinds of distances, it could take a couple hundred milliseconds for packets to reach their destination and for their acknowledgments to then return to the sender.

WAN acceleration products use a number of different technologies to optimize the speed of data transfers over a WAN, giving remote users data access comparable to that of users working in a centralized office.

In addition to using well-known technologies such as compression to maximize the efficiency of packets, WAN acceleration products limit the number of acknowledgment packets sent, which substantially minimizes network latency.

WAN acceleration appliances, such as the Riverbed and Blue Coat units eWEEK Labs tested for this report (see review, below), are deployed at the primary data center and each of an organizations remote sites.

Each WAN acceleration appliance contains a data store that identifies fragments of data within a live data stream. When data is sent across the WAN, the local appliance and the appliance at the remote site communicate with each other and ensure that data in a receiving appliances data store is not sent over the wire.

The elimination of this redundant data from the data stream can greatly reduce a companys bandwidth utilization, allowing IT managers to leverage unused bandwidth capacity to add new network services.

While it is tempting to call these solutions WAN caches, that terminology would not be completely correct because WAN accelerators cannot directly serve up data the same way a cache can. Instead, the WAN accelerator session must be authenticated and acknowledged by the source application or file server.

The primary benefit of WAN accelerators versus WAN caches is that the accelerators do not disrupt clients or applications—neither of which, for all intents and purposes, know that the WAN accelerators are in the data path.

WAN accelerators also can be used to enhance storage consolidation implementations.

With storage consolidation becoming a key goal for many companies, IT managers have enacted policies and implemented technologies to reel in critical information from remote offices back to centralized data centers.

The problem is that this data—often in the form of e-mail attachments, documents and blueprints—is out of easy reach for the remote knowledge workers who need to access it. And, no matter what kind of business you are in, nothing is more frustrating than having to wait several minutes to gain access to critical business files.

WAN acceleration products can help here, too: They can be configured to work in a bi-directional manner, speeding communications between the central site and peer sites. With this bidirectional capability in place, partners and remote workers can effectively share and collaborate with workers at headquarters.

Senior Analyst Henry Baltazar can be reached at henry_baltazar@ziffdavis.com.

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