WAN optimization (WAN acceleration)

What is WAN optimization?

WAN optimization -- also known as WAN acceleration -- is a collection of technologies and techniques used to improve the efficiency of data transfer across a wide area network (WAN) between organizations' centralized data centers and their remote locations.

In an enterprise WAN, the goal of optimization is to improve user experience by increasing the speed with which end users can access business-critical applications and information. The most common measures of data transfer efficiency are increased throughput, reduced latency and packet loss, and maximized limited bandwidth.

Why is WAN optimization important?

WAN optimization tools have been around since the early days of enterprise wide area networking when bandwidth requirements first started to exceed availability. To address the problem, the public and private sectors started researching how to improve the end-to-end throughput of Transmission Control Protocol. At the time, connectivity options were limited. Organizations relied on expensive Multiprotocol Label Switching links to connect their branch offices and data centers. WAN optimization helped network managers use bandwidth more efficiently, which improved application performance without dramatically increasing spending on expensive links.

WAN optimization use cases include the following:

• improving response times for business applications over WAN links and mobile connections;
• optimizing traffic from data center to data center for faster storage replication;
• improving enterprise investment in bandwidth; and
• moving traffic across hybrid WANs that include public cloud connectivity to access cloud applications.

WAN optimization is still in use, although, by some projections, the rise of software-defined WAN (SD-WAN) is eliminating the need for specific WAN optimization appliances to improve network performance and reliability.

How does WAN optimization work?

WAN optimization works to overcome latency, minimize packet loss and increase network throughput. It accomplishes this via an array of complementary WAN optimization techniques and technologies.

Data caching

Data caching stores frequently used information on a local host or server for faster access in the future. Because data doesn't have to travel from its point of origin to its destination over and over again, caching lightens the burden on the network.

Data deduplication

Data deduplication identifies and eliminates redundant copies of data. This reduces the amount of information that must be sent across a WAN for remote backups, replication and disaster recovery.

Data compression

Data compression shrinks the size of data to minimize bandwidth use, similar to ZIP files, as it passes through hardware or virtual WAN acceleration appliances.

Network monitoring

Network monitoring identifies nonessential traffic. By creating and enforcing rules about downloads and internet use, WAN optimization appliances can prioritize the performance of critical applications over less important ones.

Protocol acceleration

Protocol acceleration, or protocol spoofing, minimizes the burden a chatty protocol puts on the WAN. Many protocols require a client or server to wait for an acknowledgement before it can transmit again. Protocol acceleration bundles chatty protocols so they are, in effect, a single protocol, which results in fewer packet headers and network handshakes.

Traffic shaping

Traffic shaping enables network admins to decide which applications take precedence over the WAN, which prioritizes traffic and allots bandwidth accordingly.

What are some tools used for WAN optimization?

WAN optimization technology has evolved over the past several decades. Even though SD-WAN may be eclipsing its use, the WAN optimization market is still estimated at $1 billion-plus.

WAN accelerator appliances may be physical or virtual, and they may be sold as standalone products or as part of SD-WAN platforms. For example, WAN optimization controllers are virtual or physical appliances applied to both ends of a WAN connection. Single-ended physical or virtual application delivery controllers used for load balancing can also be used in WAN optimization.

WAN optimization vendors include Broadcom (Symantec), Cato Networks, Citrix, Riverbed Technology, Hewlett Packard Enterprise (Silver Peak Systems), F5 Networks, Fortinet and FatPipe Networks, among others.